From d25385d2aae709c1f9c7673cd4d03a52c35db243 Mon Sep 17 00:00:00 2001
From: Mariano Alvira <mar@devl.org>
Date: Mon, 20 Apr 2009 14:15:24 -0400
Subject: [PATCH 01/10] blink blue but with the timer.

---
 Makefile    |  2 +-
 tests/tmr.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 93 insertions(+), 1 deletion(-)
 create mode 100644 tests/tmr.c

diff --git a/Makefile b/Makefile
index f1dc502fa..1932e2fef 100644
--- a/Makefile
+++ b/Makefile
@@ -74,7 +74,7 @@ tests/rftest-tx.obj: src/maca.o src/nvm.o
 		$(OBJCOPY) ${OBJCFLAGS} -O binary $< $@
 
 %.dis:		%.obj
-		$(OBJDUMP) -D $< > $@
+		$(OBJDUMP) -SD $< > $@
 
 %.obj:		$(LDSCRIPT) %.o
 		$(LD) $(LDFLAGS) $(AOBJS) \
diff --git a/tests/tmr.c b/tests/tmr.c
new file mode 100644
index 000000000..22c12a75d
--- /dev/null
+++ b/tests/tmr.c
@@ -0,0 +1,92 @@
+/* Timer registers are all 16-bit wide with 16-bit access only */
+#define TMR_OFFSET      (0x20)
+#define TMR_BASE        (0x80007000)
+#define TMR0_BASE       (TMR_BASE)
+#define TMR1_BASE       (TMR_BASE + TMR_OFFSET*1)
+#define TMR2_BASE       (TMR_BASE + TMR_OFFSET*2)
+#define TMR3_BASE       (TMR_BASE + TMR_OFFSET*3)
+
+#define TMR_REGOFF_COMP1    (0x0)
+#define TMR_REGOFF_COMP2    (0x2)
+#define TMR_REGOFF_CAPT     (0x4)
+#define TMR_REGOFF_LOAD     (0x6)
+#define TMR_REGOFF_HOLD     (0x8)
+#define TMR_REGOFF_CNTR     (0xa)
+#define TMR_REGOFF_CTRL     (0xc)
+#define TMR_REGOFF_SCTRL    (0xe)
+#define TMR_REGOFF_CMPLD1   (0x10)
+#define TMR_REGOFF_CMPLD2   (0x12)
+#define TMR_REGOFF_CSCTRL   (0x14)
+#define TMR_REGOFF_ENBL     (0x1e)
+
+/* Timer 0 registers */
+#define TMR0_COMP1   (TMR0_BASE + TMR_REGOFF_COMP1)
+#define TMR0_COMP_UP TMR0_COMP1
+#define TMR0_COMP2   (TMR0_BASE + TMR_REGOFF_COMP2)
+#define TMR0_COMP_DOWN TMR0_COMP2
+#define TMR0_CAPT    (TMR0_BASE + TMR_REGOFF_CAPT)
+#define TMR0_LOAD    (TMR0_BASE + TMR_REGOFF_LOAD)
+#define TMR0_HOLD    (TMR0_BASE + TMR_REGOFF_HOLD)
+#define TMR0_CNTR    (TMR0_BASE + TMR_REGOFF_CTRL)
+#define TMR0_CTRL    (TMR0_BASE + TMR_REGOFF_CTRL)
+#define TMR0_SCTRL   (TMR0_BASE + TMR_REGOFF_SCTRL)
+#define TMR0_CMPLD1  (TMR0_BASE + TMR_REGOFF_CMPLD1)
+#define TMR0_CMPLD2  (TMR0_BASE + TMR_REGOFF_CMPLD2)
+#define TMR0_CSCTRL  (TMR0_BASE + TMR_REGOFF_CSCTRL)
+
+/* one enable register to rule them all */
+#define TMR_ENBL    TMR0_BASE + TMR_REGOFF_ENBL
+
+#define MBAR_GPIO       0x80000000
+#define GPIO_PAD_DIR0   0x80000000
+#define GPIO_DATA0      0x80000008
+#define UART1_DATA      0x80005008
+#define DELAY 400000
+
+#define reg32(x) (*(volatile uint32_t *)(x))
+#define reg16(x) (*(volatile uint16_t *)(x))
+
+#include "embedded_types.h"
+
+__attribute__ ((section ("startup")))
+void main(void) {
+
+	/* pin direction */
+	reg32(GPIO_PAD_DIR0) = 0x00000400;
+
+	/* timer setup */
+	/* CTRL */
+#define COUNT_MODE 1      /* use rising edge of primary source */
+#define PRIME_SRC  0xf    /* Perip. clock with 128 prescale (for 24Mhz = 187500Hz)*/
+#define SEC_SRC    0      /* don't need this */
+#define ONCE       0      /* keep counting */
+#define LEN        1      /* count until compare then reload with value in LOAD */
+#define DIR        0      /* count up */
+#define CO_INIT    0      /* other counters cannot force a re-initialization of this counter */
+#define OUT_MODE   0      /* OFLAG is asserted while counter is active */
+
+	reg16(TMR_ENBL) = 0;                     /* tmrs reset to enabled */
+	reg16(TMR0_SCTRL) = 0;
+	reg16(TMR0_LOAD) = 0;                    /* reload to zero */
+	reg16(TMR0_COMP_UP) = 18750;             /* trigger a reload at the end */
+	reg16(TMR0_CMPLD1) = 18750;              /* compare 1 triggered reload level, 10HZ maybe? */
+	reg16(TMR0_CNTR) = 0;                    /* reset count register */
+	reg16(TMR0_CTRL) = (COUNT_MODE<<13) | (PRIME_SRC<<9) | (SEC_SRC<<7) | (ONCE<<6) | (LEN<<5) | (DIR<<4) | (CO_INIT<<3) | (OUT_MODE);
+	reg16(TMR_ENBL) = 0xf;                   /* enable all the timers --- why not? */
+
+	while(1) {
+
+		/* blink on */
+		reg32(GPIO_DATA0) = 0x00000400;
+		
+		while((reg16(TMR0_SCTRL)>>15) == 0) { continue; }
+		reg16(TMR0_SCTRL) = 0; /*clear bit 15, and all the others --- should be ok, but clearly not "the right thing to do" */
+
+		/* blink off */
+		reg32(GPIO_DATA0) = 0x00000000;
+
+		while((reg16(TMR0_SCTRL)>>15) == 0) { continue; }
+		reg16(TMR0_SCTRL) = 0; /*clear bit 15, and all the others --- should be ok, but clearly not "the right thing to do" */
+
+	};
+}

From e012142abe2f1bcb4870fd9c5c35329ba2ce4f61 Mon Sep 17 00:00:00 2001
From: Mariano Alvira <mar@devl.org>
Date: Mon, 20 Apr 2009 14:28:53 -0400
Subject: [PATCH 02/10] initial interrupt stuff

taken from Contiki
---
 src/interrupt-utils.c |  84 +++++++++++++
 src/interrupt-utils.h | 272 ++++++++++++++++++++++++++++++++++++++++++
 src/sys-interrupt.c   | 100 ++++++++++++++++
 src/sys-interrupt.h   |  31 +++++
 tests/tmr-ints.c      |  92 ++++++++++++++
 5 files changed, 579 insertions(+)
 create mode 100644 src/interrupt-utils.c
 create mode 100644 src/interrupt-utils.h
 create mode 100644 src/sys-interrupt.c
 create mode 100644 src/sys-interrupt.h
 create mode 100644 tests/tmr-ints.c

diff --git a/src/interrupt-utils.c b/src/interrupt-utils.c
new file mode 100644
index 000000000..cd3e1bd81
--- /dev/null
+++ b/src/interrupt-utils.c
@@ -0,0 +1,84 @@
+/******************************************************************************
+ *
+ * $RCSfile: interrupt-utils.c,v $
+ * $Revision: 1.2 $
+ *
+ * This module provides the interface routines for setting up and
+ * controlling the various interrupt modes present on the ARM processor.
+ * Copyright 2004, R O SoftWare
+ * No guarantees, warrantees, or promises, implied or otherwise.
+ * May be used for hobby or commercial purposes provided copyright
+ * notice remains intact.
+ *
+ *****************************************************************************/
+#include "interrupt-utils.h"
+
+#define IRQ_MASK 0x00000080
+#define FIQ_MASK 0x00000040
+#define INT_MASK (IRQ_MASK | FIQ_MASK)
+
+static inline unsigned __get_cpsr(void)
+{
+  unsigned long retval;
+  asm volatile (" mrs  %0, cpsr" : "=r" (retval) : /* no inputs */  );
+  return retval;
+}
+
+static inline void __set_cpsr(unsigned val)
+{
+  asm volatile (" msr  cpsr_c, %0" : /* no outputs */ : "r" (val)  );
+}
+
+unsigned disableIRQ(void)
+{
+  unsigned _cpsr;
+
+  _cpsr = __get_cpsr();
+  __set_cpsr(_cpsr | IRQ_MASK);
+  return _cpsr;
+}
+
+unsigned restoreIRQ(unsigned oldCPSR)
+{
+  unsigned _cpsr;
+
+  _cpsr = __get_cpsr();
+  __set_cpsr((_cpsr & ~IRQ_MASK) | (oldCPSR & IRQ_MASK));
+  return _cpsr;
+}
+
+unsigned enableIRQ(void)
+{
+  unsigned _cpsr;
+
+  _cpsr = __get_cpsr();
+  __set_cpsr(_cpsr & ~IRQ_MASK);
+  return _cpsr;
+}
+
+unsigned disableFIQ(void)
+{
+  unsigned _cpsr;
+
+  _cpsr = __get_cpsr();
+  __set_cpsr(_cpsr | FIQ_MASK);
+  return _cpsr;
+}
+
+unsigned restoreFIQ(unsigned oldCPSR)
+{
+  unsigned _cpsr;
+
+  _cpsr = __get_cpsr();
+  __set_cpsr((_cpsr & ~FIQ_MASK) | (oldCPSR & FIQ_MASK));
+  return _cpsr;
+}
+
+unsigned enableFIQ(void)
+{
+  unsigned _cpsr;
+
+  _cpsr = __get_cpsr();
+  __set_cpsr(_cpsr & ~FIQ_MASK);
+  return _cpsr;
+}
diff --git a/src/interrupt-utils.h b/src/interrupt-utils.h
new file mode 100644
index 000000000..29b307d88
--- /dev/null
+++ b/src/interrupt-utils.h
@@ -0,0 +1,272 @@
+/*
+ *  Defines and Macros for Interrupt-Service-Routines
+ *  collected and partly created by
+ *  Martin Thomas <mthomas@rhrk.uni-kl.de>
+ *
+ *  Copyright 2005 M. Thomas
+ *  No guarantees, warrantees, or promises, implied or otherwise.
+ *  May be used for hobby or commercial purposes provided copyright
+ *  notice remains intact.
+ */
+
+#ifndef interrupt_utils_
+#define interrupt_utils_
+
+/* 
+   The following defines are usefull for 
+   interrupt service routine declarations.
+*/
+
+/* 
+   RAMFUNC 
+   Attribute which defines a function to be located 
+   in memory section .fastrun and called via "long calls". 
+   See linker-skript and startup-code to see how the
+   .fastrun-section is handled.
+   The definition is not only useful for ISRs but since
+   ISRs should be executed fast the macro is defined in
+   this header.
+*/
+#define RAMFUNC __attribute__ ((long_call, section (".fastrun")))
+
+
+/*
+  INTFUNC
+  standard attribute for arm-elf-gcc which marks
+  a function as ISR (for the VIC). Since gcc seems
+  to produce wrong code if this attribute is used in
+  thumb/thumb-interwork the attribute should only be
+  used for "pure ARM-mode" binaries.
+*/
+#define INTFUNC __attribute__ ((interrupt("IRQ"))) 
+
+
+/*
+  NACKEDFUNC
+  gcc will not add any code to a function declared
+  "nacked". The user has to take care to save registers
+  and add the needed code for ISR functions. Some
+  macros for this tasks are provided below.
+*/
+#define NACKEDFUNC __attribute__((naked))
+
+
+/******************************************************************************
+ *
+ * MACRO Name: ISR_STORE()
+ *
+ * Description:
+ *    This MACRO is used upon entry to an ISR with interrupt nesting.  
+ *    Should be used together with ISR_ENABLE_NEST(). The MACRO
+ *    performs the following steps:
+ *
+ *    1 - Save the non-banked registers r0-r12 and lr onto the IRQ stack.
+ *
+ *****************************************************************************/
+#define ISR_STORE() asm volatile( \
+ "STMDB SP!,{R0-R12,LR}\n" )
+ 
+ /******************************************************************************
+ *
+ * MACRO Name: ISR_RESTORE()
+ *
+ * Description:
+ *    This MACRO is used upon exit from an ISR with interrupt nesting.  
+ *    Should be used together with ISR_DISABLE_NEST(). The MACRO
+ *    performs the following steps:
+ *
+ *    1 - Load the non-banked registers r0-r12 and lr from the IRQ stack.
+ *    2 - Adjusts resume adress
+ *
+ *****************************************************************************/
+#define ISR_RESTORE()  asm volatile( \
+ "LDMIA SP!,{R0-R12,LR}\n" \
+ "SUBS  R15,R14,#0x0004\n" ) 
+
+/******************************************************************************
+ *
+ * MACRO Name: ISR_ENABLE_NEST()
+ *
+ * Description:
+ *    This MACRO is used upon entry from an ISR with interrupt nesting.  
+ *    Should be used after ISR_STORE. 
+ *
+ *****************************************************************************/
+
+#define ISR_ENABLE_NEST() asm volatile( \
+ "MRS     LR, SPSR \n"  \
+ "STMFD   SP!, {LR} \n" \
+ "MSR     CPSR_c, #0x1f \n" \
+ "STMFD   SP!, {LR} " )
+
+/******************************************************************************
+ *
+ * MACRO Name: ISR_DISABLE_NEST()
+ *
+ * Description:
+ *    This MACRO is used upon entry from an ISR with interrupt nesting.  
+ *    Should be used before ISR_RESTORE. 
+ *
+ *****************************************************************************/
+
+#define ISR_DISABLE_NEST() asm volatile(  \
+ "LDMFD   SP!, {LR} \n" \
+ "MSR     CPSR_c, #0x92 \n" \
+ "LDMFD   SP!, {LR} \n" \
+ "MSR     SPSR_cxsf, LR \n" )
+
+
+ 
+/*
+ * The following marcos are from the file "armVIC.h" by:
+ *
+ * Copyright 2004, R O SoftWare
+ * No guarantees, warrantees, or promises, implied or otherwise.
+ * May be used for hobby or commercial purposes provided copyright
+ * notice remains intact.
+ * 
+ */ 
+ 
+/******************************************************************************
+ *
+ * MACRO Name: ISR_ENTRY()
+ *
+ * Description:
+ *    This MACRO is used upon entry to an ISR.  The current version of
+ *    the gcc compiler for ARM does not produce correct code for
+ *    interrupt routines to operate properly with THUMB code.  The MACRO
+ *    performs the following steps:
+ *
+ *    1 - Adjust address at which execution should resume after servicing
+ *        ISR to compensate for IRQ entry
+ *    2 - Save the non-banked registers r0-r12 and lr onto the IRQ stack.
+ *    3 - Get the status of the interrupted program is in SPSR.
+ *    4 - Push it onto the IRQ stack as well.
+ *
+ *****************************************************************************/
+#define ISR_ENTRY() asm volatile(" sub   lr, lr,#4\n" \
+                                 " stmfd sp!,{r0-r12,lr}\n" \
+                                 " mrs   r1, spsr\n" \
+                                 " stmfd sp!,{r1}")
+
+/******************************************************************************
+ *
+ * MACRO Name: ISR_EXIT()
+ *
+ * Description:
+ *    This MACRO is used to exit an ISR.  The current version of the gcc
+ *    compiler for ARM does not produce correct code for interrupt
+ *    routines to operate properly with THUMB code.  The MACRO performs
+ *    the following steps:
+ *
+ *    1 - Recover SPSR value from stack       
+ *    2 - and restore  its value                   
+ *    3 - Pop the return address & the saved general registers from
+ *        the IRQ stack & return
+ *
+ *****************************************************************************/
+#define ISR_EXIT()  asm volatile(" ldmfd sp!,{r1}\n" \
+                                 " msr   spsr_c,r1\n" \
+                                 " ldmfd sp!,{r0-r12,pc}^") 
+  
+/******************************************************************************
+ *
+ * Function Name: disableIRQ()
+ *
+ * Description:
+ *    This function sets the IRQ disable bit in the status register
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned disableIRQ(void);
+
+/******************************************************************************
+ *
+ * Function Name: enableIRQ()
+ *
+ * Description:
+ *    This function clears the IRQ disable bit in the status register
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned enableIRQ(void);
+
+/******************************************************************************
+ *
+ * Function Name: restoreIRQ()
+ *
+ * Description:
+ *    This function restores the IRQ disable bit in the status register
+ *    to the value contained within passed oldCPSR
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned restoreIRQ(unsigned oldCPSR);
+
+/******************************************************************************
+ *
+ * Function Name: disableFIQ()
+ *
+ * Description:
+ *    This function sets the FIQ disable bit in the status register
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned disableFIQ(void);
+
+/******************************************************************************
+ *
+ * Function Name: enableFIQ()
+ *
+ * Description:
+ *    This function clears the FIQ disable bit in the status register
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned enableFIQ(void);
+
+/******************************************************************************
+ *
+ * Function Name: restoreFIQ()
+ *
+ * Description:
+ *    This function restores the FIQ disable bit in the status register
+ *    to the value contained within passed oldCPSR
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned restoreFIQ(unsigned oldCPSR);
+
+
+#endif
+
diff --git a/src/sys-interrupt.c b/src/sys-interrupt.c
new file mode 100644
index 000000000..b540145cb
--- /dev/null
+++ b/src/sys-interrupt.c
@@ -0,0 +1,100 @@
+#include <sys-interrupt.h>
+#include <interrupt-utils.h>
+#include <AT91SAM7S64.h>
+
+#define ATTR
+
+#ifndef NULL
+#define NULL 0
+#endif
+
+
+static SystemInterruptHandler *handlers = NULL;
+
+static void
+system_int_safe (void) __attribute__((noinline));
+
+static void
+system_int_safe (void) 
+{
+  SystemInterruptHandler *h;
+  h = handlers;
+  while (h) {
+    if (h->handler()) break;
+    h = h->next;
+  }
+}
+  
+static void NACKEDFUNC ATTR
+system_int (void) /* System Interrupt Handler */ 
+{
+  ISR_ENTRY();
+  system_int_safe();
+  *AT91C_AIC_EOICR = 0;                   /* End of Interrupt */
+  ISR_EXIT();
+}
+
+static unsigned int enabled = 0; /* Number of times the system
+				    interrupt has been enabled */
+
+#define DIS_INT *AT91C_AIC_IDCR = (1 << AT91C_ID_SYS)
+#define EN_INT if (enabled > 0) *AT91C_AIC_IECR = (1 << AT91C_ID_SYS)
+
+void
+sys_interrupt_enable()
+{
+  if (enabled++ == 0) {
+    /* Level trigged at priority 5 */
+    AT91C_AIC_SMR[AT91C_ID_SYS] = AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL | 5;
+    /* Interrupt vector */
+    AT91C_AIC_SVR[AT91C_ID_SYS] = (unsigned long) system_int;
+    /* Enable */
+    EN_INT;
+  }
+}
+
+
+void
+sys_interrupt_disable()
+{
+  if (--enabled == 0) {
+    DIS_INT;
+  }
+}
+
+void
+sys_interrupt_append_handler(SystemInterruptHandler *handler)
+{
+  SystemInterruptHandler **h = &handlers;
+  while(*h) {
+    h = &(*h)->next;
+  }
+  DIS_INT;
+  *h = handler;
+  handler->next = NULL;
+  EN_INT;
+}
+
+void
+sys_interrupt_prepend_handler(SystemInterruptHandler *handler)
+{
+  DIS_INT;
+  handler->next = handlers;
+  handlers = handler;
+  EN_INT;
+}
+
+void
+sys_interrupt_remove_handler(SystemInterruptHandler *handler)
+{
+  SystemInterruptHandler **h = &handlers;
+  while(*h) {
+    if (*h == handler) {
+      DIS_INT;
+      *h = handler->next;
+      EN_INT;
+      break;
+    }
+    h = &(*h)->next;
+  }
+}
diff --git a/src/sys-interrupt.h b/src/sys-interrupt.h
new file mode 100644
index 000000000..433db4a0f
--- /dev/null
+++ b/src/sys-interrupt.h
@@ -0,0 +1,31 @@
+#ifndef __SYS_INTERRUPT_H__QIHZ66NP8K__
+#define __SYS_INTERRUPT_H__QIHZ66NP8K__
+
+
+/* Returns true if it handled an activbe interrupt */
+typedef int (*SystemInterruptFunc)();
+
+typedef struct _SystemInterruptHandler SystemInterruptHandler;
+struct _SystemInterruptHandler
+{
+  SystemInterruptHandler *next;
+  SystemInterruptFunc handler;
+};
+
+
+void
+sys_interrupt_enable();
+
+void
+sys_interrupt_disable();
+
+void
+sys_interrupt_append_handler(SystemInterruptHandler *handler);
+
+void
+sys_interrupt_prepend_handler(SystemInterruptHandler *handler);
+
+void
+sys_interrupt_remove_handler(SystemInterruptHandler *handler);
+
+#endif /* __SYS_INTERRUPT_H__QIHZ66NP8K__ */
diff --git a/tests/tmr-ints.c b/tests/tmr-ints.c
new file mode 100644
index 000000000..22c12a75d
--- /dev/null
+++ b/tests/tmr-ints.c
@@ -0,0 +1,92 @@
+/* Timer registers are all 16-bit wide with 16-bit access only */
+#define TMR_OFFSET      (0x20)
+#define TMR_BASE        (0x80007000)
+#define TMR0_BASE       (TMR_BASE)
+#define TMR1_BASE       (TMR_BASE + TMR_OFFSET*1)
+#define TMR2_BASE       (TMR_BASE + TMR_OFFSET*2)
+#define TMR3_BASE       (TMR_BASE + TMR_OFFSET*3)
+
+#define TMR_REGOFF_COMP1    (0x0)
+#define TMR_REGOFF_COMP2    (0x2)
+#define TMR_REGOFF_CAPT     (0x4)
+#define TMR_REGOFF_LOAD     (0x6)
+#define TMR_REGOFF_HOLD     (0x8)
+#define TMR_REGOFF_CNTR     (0xa)
+#define TMR_REGOFF_CTRL     (0xc)
+#define TMR_REGOFF_SCTRL    (0xe)
+#define TMR_REGOFF_CMPLD1   (0x10)
+#define TMR_REGOFF_CMPLD2   (0x12)
+#define TMR_REGOFF_CSCTRL   (0x14)
+#define TMR_REGOFF_ENBL     (0x1e)
+
+/* Timer 0 registers */
+#define TMR0_COMP1   (TMR0_BASE + TMR_REGOFF_COMP1)
+#define TMR0_COMP_UP TMR0_COMP1
+#define TMR0_COMP2   (TMR0_BASE + TMR_REGOFF_COMP2)
+#define TMR0_COMP_DOWN TMR0_COMP2
+#define TMR0_CAPT    (TMR0_BASE + TMR_REGOFF_CAPT)
+#define TMR0_LOAD    (TMR0_BASE + TMR_REGOFF_LOAD)
+#define TMR0_HOLD    (TMR0_BASE + TMR_REGOFF_HOLD)
+#define TMR0_CNTR    (TMR0_BASE + TMR_REGOFF_CTRL)
+#define TMR0_CTRL    (TMR0_BASE + TMR_REGOFF_CTRL)
+#define TMR0_SCTRL   (TMR0_BASE + TMR_REGOFF_SCTRL)
+#define TMR0_CMPLD1  (TMR0_BASE + TMR_REGOFF_CMPLD1)
+#define TMR0_CMPLD2  (TMR0_BASE + TMR_REGOFF_CMPLD2)
+#define TMR0_CSCTRL  (TMR0_BASE + TMR_REGOFF_CSCTRL)
+
+/* one enable register to rule them all */
+#define TMR_ENBL    TMR0_BASE + TMR_REGOFF_ENBL
+
+#define MBAR_GPIO       0x80000000
+#define GPIO_PAD_DIR0   0x80000000
+#define GPIO_DATA0      0x80000008
+#define UART1_DATA      0x80005008
+#define DELAY 400000
+
+#define reg32(x) (*(volatile uint32_t *)(x))
+#define reg16(x) (*(volatile uint16_t *)(x))
+
+#include "embedded_types.h"
+
+__attribute__ ((section ("startup")))
+void main(void) {
+
+	/* pin direction */
+	reg32(GPIO_PAD_DIR0) = 0x00000400;
+
+	/* timer setup */
+	/* CTRL */
+#define COUNT_MODE 1      /* use rising edge of primary source */
+#define PRIME_SRC  0xf    /* Perip. clock with 128 prescale (for 24Mhz = 187500Hz)*/
+#define SEC_SRC    0      /* don't need this */
+#define ONCE       0      /* keep counting */
+#define LEN        1      /* count until compare then reload with value in LOAD */
+#define DIR        0      /* count up */
+#define CO_INIT    0      /* other counters cannot force a re-initialization of this counter */
+#define OUT_MODE   0      /* OFLAG is asserted while counter is active */
+
+	reg16(TMR_ENBL) = 0;                     /* tmrs reset to enabled */
+	reg16(TMR0_SCTRL) = 0;
+	reg16(TMR0_LOAD) = 0;                    /* reload to zero */
+	reg16(TMR0_COMP_UP) = 18750;             /* trigger a reload at the end */
+	reg16(TMR0_CMPLD1) = 18750;              /* compare 1 triggered reload level, 10HZ maybe? */
+	reg16(TMR0_CNTR) = 0;                    /* reset count register */
+	reg16(TMR0_CTRL) = (COUNT_MODE<<13) | (PRIME_SRC<<9) | (SEC_SRC<<7) | (ONCE<<6) | (LEN<<5) | (DIR<<4) | (CO_INIT<<3) | (OUT_MODE);
+	reg16(TMR_ENBL) = 0xf;                   /* enable all the timers --- why not? */
+
+	while(1) {
+
+		/* blink on */
+		reg32(GPIO_DATA0) = 0x00000400;
+		
+		while((reg16(TMR0_SCTRL)>>15) == 0) { continue; }
+		reg16(TMR0_SCTRL) = 0; /*clear bit 15, and all the others --- should be ok, but clearly not "the right thing to do" */
+
+		/* blink off */
+		reg32(GPIO_DATA0) = 0x00000000;
+
+		while((reg16(TMR0_SCTRL)>>15) == 0) { continue; }
+		reg16(TMR0_SCTRL) = 0; /*clear bit 15, and all the others --- should be ok, but clearly not "the right thing to do" */
+
+	};
+}

From 4f45e439844eca2940ebe93704c47822369d273d Mon Sep 17 00:00:00 2001
From: Mariano Alvira <mar@devl.org>
Date: Mon, 20 Apr 2009 14:29:20 -0400
Subject: [PATCH 03/10] nvm source file

---
 src/nvm.c | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 src/nvm.c

diff --git a/src/nvm.c b/src/nvm.c
new file mode 100644
index 000000000..c4d54d513
--- /dev/null
+++ b/src/nvm.c
@@ -0,0 +1,5 @@
+#include "nvm.h"
+
+volatile nvmErr_t (*nvm_detect)(nvmInterface_t nvmInterface,nvmType_t* pNvmType) = 0x00006cb9;
+volatile nvmErr_t (*nvm_read)(nvmInterface_t nvmInterface , nvmType_t nvmType , void *pDest, uint32_t address, uint32_t numBytes) = 0x00006d69;
+volatile void(*nvm_setsvar)(uint32_t zero_for_awesome) = 0x00007085;

From cfd985c8371d2678de0d372f97af946b32b1accb Mon Sep 17 00:00:00 2001
From: Mariano Alvira <mar@devl.org>
Date: Mon, 20 Apr 2009 15:42:21 -0400
Subject: [PATCH 04/10] modified at91 interrupt code from contiki to use the
 mc1322x registers and to produce code that works with THUMB.

---
 include/interrupt-utils.h | 272 ++++++++++++++++++++++++++++++++++++++
 include/sys-interrupt.h   |  31 +++++
 src/interrupt-utils.c     |  19 ++-
 src/sys-interrupt.c       |  17 +--
 4 files changed, 325 insertions(+), 14 deletions(-)
 create mode 100644 include/interrupt-utils.h
 create mode 100644 include/sys-interrupt.h

diff --git a/include/interrupt-utils.h b/include/interrupt-utils.h
new file mode 100644
index 000000000..29b307d88
--- /dev/null
+++ b/include/interrupt-utils.h
@@ -0,0 +1,272 @@
+/*
+ *  Defines and Macros for Interrupt-Service-Routines
+ *  collected and partly created by
+ *  Martin Thomas <mthomas@rhrk.uni-kl.de>
+ *
+ *  Copyright 2005 M. Thomas
+ *  No guarantees, warrantees, or promises, implied or otherwise.
+ *  May be used for hobby or commercial purposes provided copyright
+ *  notice remains intact.
+ */
+
+#ifndef interrupt_utils_
+#define interrupt_utils_
+
+/* 
+   The following defines are usefull for 
+   interrupt service routine declarations.
+*/
+
+/* 
+   RAMFUNC 
+   Attribute which defines a function to be located 
+   in memory section .fastrun and called via "long calls". 
+   See linker-skript and startup-code to see how the
+   .fastrun-section is handled.
+   The definition is not only useful for ISRs but since
+   ISRs should be executed fast the macro is defined in
+   this header.
+*/
+#define RAMFUNC __attribute__ ((long_call, section (".fastrun")))
+
+
+/*
+  INTFUNC
+  standard attribute for arm-elf-gcc which marks
+  a function as ISR (for the VIC). Since gcc seems
+  to produce wrong code if this attribute is used in
+  thumb/thumb-interwork the attribute should only be
+  used for "pure ARM-mode" binaries.
+*/
+#define INTFUNC __attribute__ ((interrupt("IRQ"))) 
+
+
+/*
+  NACKEDFUNC
+  gcc will not add any code to a function declared
+  "nacked". The user has to take care to save registers
+  and add the needed code for ISR functions. Some
+  macros for this tasks are provided below.
+*/
+#define NACKEDFUNC __attribute__((naked))
+
+
+/******************************************************************************
+ *
+ * MACRO Name: ISR_STORE()
+ *
+ * Description:
+ *    This MACRO is used upon entry to an ISR with interrupt nesting.  
+ *    Should be used together with ISR_ENABLE_NEST(). The MACRO
+ *    performs the following steps:
+ *
+ *    1 - Save the non-banked registers r0-r12 and lr onto the IRQ stack.
+ *
+ *****************************************************************************/
+#define ISR_STORE() asm volatile( \
+ "STMDB SP!,{R0-R12,LR}\n" )
+ 
+ /******************************************************************************
+ *
+ * MACRO Name: ISR_RESTORE()
+ *
+ * Description:
+ *    This MACRO is used upon exit from an ISR with interrupt nesting.  
+ *    Should be used together with ISR_DISABLE_NEST(). The MACRO
+ *    performs the following steps:
+ *
+ *    1 - Load the non-banked registers r0-r12 and lr from the IRQ stack.
+ *    2 - Adjusts resume adress
+ *
+ *****************************************************************************/
+#define ISR_RESTORE()  asm volatile( \
+ "LDMIA SP!,{R0-R12,LR}\n" \
+ "SUBS  R15,R14,#0x0004\n" ) 
+
+/******************************************************************************
+ *
+ * MACRO Name: ISR_ENABLE_NEST()
+ *
+ * Description:
+ *    This MACRO is used upon entry from an ISR with interrupt nesting.  
+ *    Should be used after ISR_STORE. 
+ *
+ *****************************************************************************/
+
+#define ISR_ENABLE_NEST() asm volatile( \
+ "MRS     LR, SPSR \n"  \
+ "STMFD   SP!, {LR} \n" \
+ "MSR     CPSR_c, #0x1f \n" \
+ "STMFD   SP!, {LR} " )
+
+/******************************************************************************
+ *
+ * MACRO Name: ISR_DISABLE_NEST()
+ *
+ * Description:
+ *    This MACRO is used upon entry from an ISR with interrupt nesting.  
+ *    Should be used before ISR_RESTORE. 
+ *
+ *****************************************************************************/
+
+#define ISR_DISABLE_NEST() asm volatile(  \
+ "LDMFD   SP!, {LR} \n" \
+ "MSR     CPSR_c, #0x92 \n" \
+ "LDMFD   SP!, {LR} \n" \
+ "MSR     SPSR_cxsf, LR \n" )
+
+
+ 
+/*
+ * The following marcos are from the file "armVIC.h" by:
+ *
+ * Copyright 2004, R O SoftWare
+ * No guarantees, warrantees, or promises, implied or otherwise.
+ * May be used for hobby or commercial purposes provided copyright
+ * notice remains intact.
+ * 
+ */ 
+ 
+/******************************************************************************
+ *
+ * MACRO Name: ISR_ENTRY()
+ *
+ * Description:
+ *    This MACRO is used upon entry to an ISR.  The current version of
+ *    the gcc compiler for ARM does not produce correct code for
+ *    interrupt routines to operate properly with THUMB code.  The MACRO
+ *    performs the following steps:
+ *
+ *    1 - Adjust address at which execution should resume after servicing
+ *        ISR to compensate for IRQ entry
+ *    2 - Save the non-banked registers r0-r12 and lr onto the IRQ stack.
+ *    3 - Get the status of the interrupted program is in SPSR.
+ *    4 - Push it onto the IRQ stack as well.
+ *
+ *****************************************************************************/
+#define ISR_ENTRY() asm volatile(" sub   lr, lr,#4\n" \
+                                 " stmfd sp!,{r0-r12,lr}\n" \
+                                 " mrs   r1, spsr\n" \
+                                 " stmfd sp!,{r1}")
+
+/******************************************************************************
+ *
+ * MACRO Name: ISR_EXIT()
+ *
+ * Description:
+ *    This MACRO is used to exit an ISR.  The current version of the gcc
+ *    compiler for ARM does not produce correct code for interrupt
+ *    routines to operate properly with THUMB code.  The MACRO performs
+ *    the following steps:
+ *
+ *    1 - Recover SPSR value from stack       
+ *    2 - and restore  its value                   
+ *    3 - Pop the return address & the saved general registers from
+ *        the IRQ stack & return
+ *
+ *****************************************************************************/
+#define ISR_EXIT()  asm volatile(" ldmfd sp!,{r1}\n" \
+                                 " msr   spsr_c,r1\n" \
+                                 " ldmfd sp!,{r0-r12,pc}^") 
+  
+/******************************************************************************
+ *
+ * Function Name: disableIRQ()
+ *
+ * Description:
+ *    This function sets the IRQ disable bit in the status register
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned disableIRQ(void);
+
+/******************************************************************************
+ *
+ * Function Name: enableIRQ()
+ *
+ * Description:
+ *    This function clears the IRQ disable bit in the status register
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned enableIRQ(void);
+
+/******************************************************************************
+ *
+ * Function Name: restoreIRQ()
+ *
+ * Description:
+ *    This function restores the IRQ disable bit in the status register
+ *    to the value contained within passed oldCPSR
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned restoreIRQ(unsigned oldCPSR);
+
+/******************************************************************************
+ *
+ * Function Name: disableFIQ()
+ *
+ * Description:
+ *    This function sets the FIQ disable bit in the status register
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned disableFIQ(void);
+
+/******************************************************************************
+ *
+ * Function Name: enableFIQ()
+ *
+ * Description:
+ *    This function clears the FIQ disable bit in the status register
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned enableFIQ(void);
+
+/******************************************************************************
+ *
+ * Function Name: restoreFIQ()
+ *
+ * Description:
+ *    This function restores the FIQ disable bit in the status register
+ *    to the value contained within passed oldCPSR
+ *
+ * Calling Sequence: 
+ *    void
+ *
+ * Returns:
+ *    previous value of CPSR
+ *
+ *****************************************************************************/
+unsigned restoreFIQ(unsigned oldCPSR);
+
+
+#endif
+
diff --git a/include/sys-interrupt.h b/include/sys-interrupt.h
new file mode 100644
index 000000000..433db4a0f
--- /dev/null
+++ b/include/sys-interrupt.h
@@ -0,0 +1,31 @@
+#ifndef __SYS_INTERRUPT_H__QIHZ66NP8K__
+#define __SYS_INTERRUPT_H__QIHZ66NP8K__
+
+
+/* Returns true if it handled an activbe interrupt */
+typedef int (*SystemInterruptFunc)();
+
+typedef struct _SystemInterruptHandler SystemInterruptHandler;
+struct _SystemInterruptHandler
+{
+  SystemInterruptHandler *next;
+  SystemInterruptFunc handler;
+};
+
+
+void
+sys_interrupt_enable();
+
+void
+sys_interrupt_disable();
+
+void
+sys_interrupt_append_handler(SystemInterruptHandler *handler);
+
+void
+sys_interrupt_prepend_handler(SystemInterruptHandler *handler);
+
+void
+sys_interrupt_remove_handler(SystemInterruptHandler *handler);
+
+#endif /* __SYS_INTERRUPT_H__QIHZ66NP8K__ */
diff --git a/src/interrupt-utils.c b/src/interrupt-utils.c
index cd3e1bd81..2e2f7c1e2 100644
--- a/src/interrupt-utils.c
+++ b/src/interrupt-utils.c
@@ -17,18 +17,29 @@
 #define FIQ_MASK 0x00000040
 #define INT_MASK (IRQ_MASK | FIQ_MASK)
 
-static inline unsigned __get_cpsr(void)
+unsigned __get_cpsr(void)
 {
   unsigned long retval;
-  asm volatile (" mrs  %0, cpsr" : "=r" (retval) : /* no inputs */  );
+  asm volatile (
+	  ".code 32;"
+	  "mrs  %0, cpsr;"
+	  ".code 16;"
+	  : "=r" (retval) :
+	  );
   return retval;
 }
 
-static inline void __set_cpsr(unsigned val)
+void __set_cpsr(unsigned val)
 {
-  asm volatile (" msr  cpsr_c, %0" : /* no outputs */ : "r" (val)  );
+	asm volatile (
+		".code 32;"
+		"msr cpsr_c, %0;"
+		".code 16;"
+		: : "r" (val)
+		);
 }
 
+
 unsigned disableIRQ(void)
 {
   unsigned _cpsr;
diff --git a/src/sys-interrupt.c b/src/sys-interrupt.c
index b540145cb..6a8b36e1d 100644
--- a/src/sys-interrupt.c
+++ b/src/sys-interrupt.c
@@ -1,6 +1,7 @@
-#include <sys-interrupt.h>
-#include <interrupt-utils.h>
-#include <AT91SAM7S64.h>
+#include "sys-interrupt.h"
+#include "interrupt-utils.h"
+
+#include "embedded_types.h"
 
 #define ATTR
 
@@ -30,24 +31,20 @@ system_int (void) /* System Interrupt Handler */
 {
   ISR_ENTRY();
   system_int_safe();
-  *AT91C_AIC_EOICR = 0;                   /* End of Interrupt */
   ISR_EXIT();
 }
 
 static unsigned int enabled = 0; /* Number of times the system
 				    interrupt has been enabled */
 
-#define DIS_INT *AT91C_AIC_IDCR = (1 << AT91C_ID_SYS)
-#define EN_INT if (enabled > 0) *AT91C_AIC_IECR = (1 << AT91C_ID_SYS)
+#define INTCNTL 0x80020000
+#define DIS_INT *((volatile uint32_t *)INTCNTL) = 3 << 19;
+#define EN_INT if (enabled > 0) *((volatile uint32_t *)INTCNTL) = 0;
 
 void
 sys_interrupt_enable()
 {
   if (enabled++ == 0) {
-    /* Level trigged at priority 5 */
-    AT91C_AIC_SMR[AT91C_ID_SYS] = AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL | 5;
-    /* Interrupt vector */
-    AT91C_AIC_SVR[AT91C_ID_SYS] = (unsigned long) system_int;
     /* Enable */
     EN_INT;
   }

From 28c1ed2105114f8a3e99f8cef83e08e1516a8daa Mon Sep 17 00:00:00 2001
From: Mariano Alvira <mar@devl.org>
Date: Mon, 20 Apr 2009 15:43:24 -0400
Subject: [PATCH 05/10] added function sections and long-calls

---
 Makefile              |   1 +
 config.mk             |   4 +-
 src/interrupt-utils.h | 272 ------------------------------------------
 src/sys-interrupt.h   |  31 -----
 4 files changed, 3 insertions(+), 305 deletions(-)
 delete mode 100644 src/interrupt-utils.h
 delete mode 100644 src/sys-interrupt.h

diff --git a/Makefile b/Makefile
index 1932e2fef..563cd2a01 100644
--- a/Makefile
+++ b/Makefile
@@ -63,6 +63,7 @@ all:		src/start.o $(ALL)
 tests/nvm-read.obj: src/maca.o src/nvm.o
 tests/rftest-rx.obj: src/maca.o src/nvm.o
 tests/rftest-tx.obj: src/maca.o src/nvm.o
+tests/tmr-ints.c: src/interrupt-utils.o src/sys-interrupt.o
 
 %.srec:		%.obj
 		$(OBJCOPY) ${OBJCFLAGS} -O srec $< $@
diff --git a/config.mk b/config.mk
index 7352f6d74..3fb973e44 100644
--- a/config.mk
+++ b/config.mk
@@ -25,8 +25,8 @@
 
 # clean the slate ...
 PLATFORM_LDFLAGS =
-PLATFORM_RELFLAGS = -fno-strict-aliasing  -fno-common -ffixed-r8 -msoft-float
-PLATFORM_CPPFLAGS = -march=armv4t -mcallee-super-interworking -mthumb -mtune=arm7tdmi-s -mthumb-interwork -DCONFIG_ARM -D__ARM__
+PLATFORM_RELFLAGS = -fno-strict-aliasing  -fno-common -ffixed-r8 -ffunction-sections -msoft-float
+PLATFORM_CPPFLAGS = -march=armv4t -mlong-calls -mcallee-super-interworking -mthumb -mthumb-interwork -mtune=arm7tdmi-s -DCONFIG_ARM -D__ARM__
 TEXT_BASE = 0x00400000
 
 #########################################################################
diff --git a/src/interrupt-utils.h b/src/interrupt-utils.h
deleted file mode 100644
index 29b307d88..000000000
--- a/src/interrupt-utils.h
+++ /dev/null
@@ -1,272 +0,0 @@
-/*
- *  Defines and Macros for Interrupt-Service-Routines
- *  collected and partly created by
- *  Martin Thomas <mthomas@rhrk.uni-kl.de>
- *
- *  Copyright 2005 M. Thomas
- *  No guarantees, warrantees, or promises, implied or otherwise.
- *  May be used for hobby or commercial purposes provided copyright
- *  notice remains intact.
- */
-
-#ifndef interrupt_utils_
-#define interrupt_utils_
-
-/* 
-   The following defines are usefull for 
-   interrupt service routine declarations.
-*/
-
-/* 
-   RAMFUNC 
-   Attribute which defines a function to be located 
-   in memory section .fastrun and called via "long calls". 
-   See linker-skript and startup-code to see how the
-   .fastrun-section is handled.
-   The definition is not only useful for ISRs but since
-   ISRs should be executed fast the macro is defined in
-   this header.
-*/
-#define RAMFUNC __attribute__ ((long_call, section (".fastrun")))
-
-
-/*
-  INTFUNC
-  standard attribute for arm-elf-gcc which marks
-  a function as ISR (for the VIC). Since gcc seems
-  to produce wrong code if this attribute is used in
-  thumb/thumb-interwork the attribute should only be
-  used for "pure ARM-mode" binaries.
-*/
-#define INTFUNC __attribute__ ((interrupt("IRQ"))) 
-
-
-/*
-  NACKEDFUNC
-  gcc will not add any code to a function declared
-  "nacked". The user has to take care to save registers
-  and add the needed code for ISR functions. Some
-  macros for this tasks are provided below.
-*/
-#define NACKEDFUNC __attribute__((naked))
-
-
-/******************************************************************************
- *
- * MACRO Name: ISR_STORE()
- *
- * Description:
- *    This MACRO is used upon entry to an ISR with interrupt nesting.  
- *    Should be used together with ISR_ENABLE_NEST(). The MACRO
- *    performs the following steps:
- *
- *    1 - Save the non-banked registers r0-r12 and lr onto the IRQ stack.
- *
- *****************************************************************************/
-#define ISR_STORE() asm volatile( \
- "STMDB SP!,{R0-R12,LR}\n" )
- 
- /******************************************************************************
- *
- * MACRO Name: ISR_RESTORE()
- *
- * Description:
- *    This MACRO is used upon exit from an ISR with interrupt nesting.  
- *    Should be used together with ISR_DISABLE_NEST(). The MACRO
- *    performs the following steps:
- *
- *    1 - Load the non-banked registers r0-r12 and lr from the IRQ stack.
- *    2 - Adjusts resume adress
- *
- *****************************************************************************/
-#define ISR_RESTORE()  asm volatile( \
- "LDMIA SP!,{R0-R12,LR}\n" \
- "SUBS  R15,R14,#0x0004\n" ) 
-
-/******************************************************************************
- *
- * MACRO Name: ISR_ENABLE_NEST()
- *
- * Description:
- *    This MACRO is used upon entry from an ISR with interrupt nesting.  
- *    Should be used after ISR_STORE. 
- *
- *****************************************************************************/
-
-#define ISR_ENABLE_NEST() asm volatile( \
- "MRS     LR, SPSR \n"  \
- "STMFD   SP!, {LR} \n" \
- "MSR     CPSR_c, #0x1f \n" \
- "STMFD   SP!, {LR} " )
-
-/******************************************************************************
- *
- * MACRO Name: ISR_DISABLE_NEST()
- *
- * Description:
- *    This MACRO is used upon entry from an ISR with interrupt nesting.  
- *    Should be used before ISR_RESTORE. 
- *
- *****************************************************************************/
-
-#define ISR_DISABLE_NEST() asm volatile(  \
- "LDMFD   SP!, {LR} \n" \
- "MSR     CPSR_c, #0x92 \n" \
- "LDMFD   SP!, {LR} \n" \
- "MSR     SPSR_cxsf, LR \n" )
-
-
- 
-/*
- * The following marcos are from the file "armVIC.h" by:
- *
- * Copyright 2004, R O SoftWare
- * No guarantees, warrantees, or promises, implied or otherwise.
- * May be used for hobby or commercial purposes provided copyright
- * notice remains intact.
- * 
- */ 
- 
-/******************************************************************************
- *
- * MACRO Name: ISR_ENTRY()
- *
- * Description:
- *    This MACRO is used upon entry to an ISR.  The current version of
- *    the gcc compiler for ARM does not produce correct code for
- *    interrupt routines to operate properly with THUMB code.  The MACRO
- *    performs the following steps:
- *
- *    1 - Adjust address at which execution should resume after servicing
- *        ISR to compensate for IRQ entry
- *    2 - Save the non-banked registers r0-r12 and lr onto the IRQ stack.
- *    3 - Get the status of the interrupted program is in SPSR.
- *    4 - Push it onto the IRQ stack as well.
- *
- *****************************************************************************/
-#define ISR_ENTRY() asm volatile(" sub   lr, lr,#4\n" \
-                                 " stmfd sp!,{r0-r12,lr}\n" \
-                                 " mrs   r1, spsr\n" \
-                                 " stmfd sp!,{r1}")
-
-/******************************************************************************
- *
- * MACRO Name: ISR_EXIT()
- *
- * Description:
- *    This MACRO is used to exit an ISR.  The current version of the gcc
- *    compiler for ARM does not produce correct code for interrupt
- *    routines to operate properly with THUMB code.  The MACRO performs
- *    the following steps:
- *
- *    1 - Recover SPSR value from stack       
- *    2 - and restore  its value                   
- *    3 - Pop the return address & the saved general registers from
- *        the IRQ stack & return
- *
- *****************************************************************************/
-#define ISR_EXIT()  asm volatile(" ldmfd sp!,{r1}\n" \
-                                 " msr   spsr_c,r1\n" \
-                                 " ldmfd sp!,{r0-r12,pc}^") 
-  
-/******************************************************************************
- *
- * Function Name: disableIRQ()
- *
- * Description:
- *    This function sets the IRQ disable bit in the status register
- *
- * Calling Sequence: 
- *    void
- *
- * Returns:
- *    previous value of CPSR
- *
- *****************************************************************************/
-unsigned disableIRQ(void);
-
-/******************************************************************************
- *
- * Function Name: enableIRQ()
- *
- * Description:
- *    This function clears the IRQ disable bit in the status register
- *
- * Calling Sequence: 
- *    void
- *
- * Returns:
- *    previous value of CPSR
- *
- *****************************************************************************/
-unsigned enableIRQ(void);
-
-/******************************************************************************
- *
- * Function Name: restoreIRQ()
- *
- * Description:
- *    This function restores the IRQ disable bit in the status register
- *    to the value contained within passed oldCPSR
- *
- * Calling Sequence: 
- *    void
- *
- * Returns:
- *    previous value of CPSR
- *
- *****************************************************************************/
-unsigned restoreIRQ(unsigned oldCPSR);
-
-/******************************************************************************
- *
- * Function Name: disableFIQ()
- *
- * Description:
- *    This function sets the FIQ disable bit in the status register
- *
- * Calling Sequence: 
- *    void
- *
- * Returns:
- *    previous value of CPSR
- *
- *****************************************************************************/
-unsigned disableFIQ(void);
-
-/******************************************************************************
- *
- * Function Name: enableFIQ()
- *
- * Description:
- *    This function clears the FIQ disable bit in the status register
- *
- * Calling Sequence: 
- *    void
- *
- * Returns:
- *    previous value of CPSR
- *
- *****************************************************************************/
-unsigned enableFIQ(void);
-
-/******************************************************************************
- *
- * Function Name: restoreFIQ()
- *
- * Description:
- *    This function restores the FIQ disable bit in the status register
- *    to the value contained within passed oldCPSR
- *
- * Calling Sequence: 
- *    void
- *
- * Returns:
- *    previous value of CPSR
- *
- *****************************************************************************/
-unsigned restoreFIQ(unsigned oldCPSR);
-
-
-#endif
-
diff --git a/src/sys-interrupt.h b/src/sys-interrupt.h
deleted file mode 100644
index 433db4a0f..000000000
--- a/src/sys-interrupt.h
+++ /dev/null
@@ -1,31 +0,0 @@
-#ifndef __SYS_INTERRUPT_H__QIHZ66NP8K__
-#define __SYS_INTERRUPT_H__QIHZ66NP8K__
-
-
-/* Returns true if it handled an activbe interrupt */
-typedef int (*SystemInterruptFunc)();
-
-typedef struct _SystemInterruptHandler SystemInterruptHandler;
-struct _SystemInterruptHandler
-{
-  SystemInterruptHandler *next;
-  SystemInterruptFunc handler;
-};
-
-
-void
-sys_interrupt_enable();
-
-void
-sys_interrupt_disable();
-
-void
-sys_interrupt_append_handler(SystemInterruptHandler *handler);
-
-void
-sys_interrupt_prepend_handler(SystemInterruptHandler *handler);
-
-void
-sys_interrupt_remove_handler(SystemInterruptHandler *handler);
-
-#endif /* __SYS_INTERRUPT_H__QIHZ66NP8K__ */

From 09b15558a15a4c440b82cdd1070e8d54c8ef64f8 Mon Sep 17 00:00:00 2001
From: Mariano Alvira <mar@devl.org>
Date: Mon, 20 Apr 2009 18:31:13 -0400
Subject: [PATCH 06/10] preliminary interrupts. looks like it is entering the
 isr but isn't leaving correctly.

---
 Makefile                | 19 +++++++++++----
 boot.lds                |  1 +
 include/sys-interrupt.h | 10 ++++----
 src/start.S             |  2 +-
 tests/blink-blue.c      |  3 +++
 tests/blink-green.c     |  3 +++
 tests/blink-red.c       |  3 +++
 tests/blink-white.c     |  3 +++
 tests/nvm-read.c        |  4 ++++
 tests/rftest-rx.c       |  3 +++
 tests/rftest-tx.c       |  3 +++
 tests/romimg.c          |  3 +++
 tests/tmr-ints.c        | 52 +++++++++++++++++++++++++++++------------
 tests/tmr.c             |  3 +++
 tests/uart1-loopback.c  |  3 +++
 15 files changed, 89 insertions(+), 26 deletions(-)

diff --git a/Makefile b/Makefile
index 563cd2a01..dc29499dc 100644
--- a/Makefile
+++ b/Makefile
@@ -42,7 +42,7 @@ include $(TOPDIR)/config.mk
 #########################################################################
 # blink objects....order is important (i.e. start must be first)
 
-AOBJS = 
+AOBJS =
 COBJS = $(patsubst %.c,%.o,$(wildcard src/*.c))
 TESTS = $(wildcard tests/*.c)
 TARGETS = $(patsubst %.c,%.o,$(TESTS))
@@ -58,12 +58,23 @@ ALL = $(TESTS:.c=.srec) $(TESTS:.c=.bin) $(TESTS:.c=.dis)
 
 .PRECIOUS: 	$(COBJS) $(TARGETS) $(TESTS:.c=.obj)
 
-all:		src/start.o $(ALL)
+all:		src/start.o src/isr.o $(ALL)
 
 tests/nvm-read.obj: src/maca.o src/nvm.o
 tests/rftest-rx.obj: src/maca.o src/nvm.o
 tests/rftest-tx.obj: src/maca.o src/nvm.o
-tests/tmr-ints.c: src/interrupt-utils.o src/sys-interrupt.o
+tests/tmr-ints.obj: src/interrupt-utils.o src/sys-interrupt.o src/isr.o
+
+NOTHUMB_CPPFLAGS := $(DBGFLAGS) $(OPTFLAGS) $(RELFLAGS)         \
+        -D__KERNEL__ -DTEXT_BASE=$(TEXT_BASE)           \
+        -I$(TOPDIR)/include                             \
+        -fno-builtin -ffreestanding -nostdinc -isystem  \
+        $(gccincdir) -pipe 
+NOTHUMB_CPPFLAGS_EXTRA = -march=armv4t -mlong-calls -mthumb-interwork -mtune=arm7tdmi-s -DCONFIG_ARM -D__ARM__
+
+
+src/isr.o: src/isr.c
+		$(CC) $(NOTHUMB_CPPFLAGS) $(NOTHUMB_CPPFLAGS_EXTRA) -c -o $@ $<
 
 %.srec:		%.obj
 		$(OBJCOPY) ${OBJCFLAGS} -O srec $< $@
@@ -77,7 +88,7 @@ tests/tmr-ints.c: src/interrupt-utils.o src/sys-interrupt.o
 %.dis:		%.obj
 		$(OBJDUMP) -SD $< > $@
 
-%.obj:		$(LDSCRIPT) %.o
+%.obj:		$(LDSCRIPT) %.o src/interrupt-utils.o
 		$(LD) $(LDFLAGS) $(AOBJS) \
 			--start-group $(PLATFORM_LIBS) --end-group \
 			-Map $*.map $^ -o $@
diff --git a/boot.lds b/boot.lds
index 5b6ae7aef..0d4bb767b 100644
--- a/boot.lds
+++ b/boot.lds
@@ -33,6 +33,7 @@ SECTIONS
 	.text      :
 	{
 	  src/start.o	(.text)
+	  src/isr.o	(.text)
 	  *(.text)
 	}
 
diff --git a/include/sys-interrupt.h b/include/sys-interrupt.h
index 433db4a0f..cdaf8d2c3 100644
--- a/include/sys-interrupt.h
+++ b/include/sys-interrupt.h
@@ -1,8 +1,7 @@
-#ifndef __SYS_INTERRUPT_H__QIHZ66NP8K__
-#define __SYS_INTERRUPT_H__QIHZ66NP8K__
+#ifndef __SYS_INTERRUPT_H
+#define __SYS_INTERRUPT_H
 
-
-/* Returns true if it handled an activbe interrupt */
+/* Returns true if it handled an active interrupt */
 typedef int (*SystemInterruptFunc)();
 
 typedef struct _SystemInterruptHandler SystemInterruptHandler;
@@ -12,7 +11,6 @@ struct _SystemInterruptHandler
   SystemInterruptFunc handler;
 };
 
-
 void
 sys_interrupt_enable();
 
@@ -28,4 +26,4 @@ sys_interrupt_prepend_handler(SystemInterruptHandler *handler);
 void
 sys_interrupt_remove_handler(SystemInterruptHandler *handler);
 
-#endif /* __SYS_INTERRUPT_H__QIHZ66NP8K__ */
+#endif /* __SYS_INTERRUPT_H */
diff --git a/src/start.S b/src/start.S
index ec6f93444..2e17e424e 100644
--- a/src/start.S
+++ b/src/start.S
@@ -197,7 +197,7 @@ not_used:
 
 	.align	5
 irq:
-
+	b isr
 	.align	5
 fiq:
 
diff --git a/tests/blink-blue.c b/tests/blink-blue.c
index dda1750bf..a0d59dee7 100644
--- a/tests/blink-blue.c
+++ b/tests/blink-blue.c
@@ -5,6 +5,9 @@
 #define DELAY 400000
 
 #include "embedded_types.h"
+#include "isr.h"
+
+no_isrs();
 
 __attribute__ ((section ("startup")))
 void main(void) {
diff --git a/tests/blink-green.c b/tests/blink-green.c
index 2a7aa7add..c7bed04eb 100644
--- a/tests/blink-green.c
+++ b/tests/blink-green.c
@@ -5,6 +5,9 @@
 #define DELAY 400000
 
 #include "embedded_types.h"
+#include "isr.h"
+
+no_isrs();
 
 __attribute__ ((section ("startup")))
 void main(void) {
diff --git a/tests/blink-red.c b/tests/blink-red.c
index 0780033e0..f1da55417 100644
--- a/tests/blink-red.c
+++ b/tests/blink-red.c
@@ -5,6 +5,9 @@
 #define DELAY 400000
 
 #include "embedded_types.h"
+#include "isr.h"
+
+no_isrs();
 
 __attribute__ ((section ("startup"))) void main(void) {
 	*(volatile uint32_t *)GPIO_PAD_DIR0 = 0x00000100;
diff --git a/tests/blink-white.c b/tests/blink-white.c
index 87a7f6720..18ba37308 100644
--- a/tests/blink-white.c
+++ b/tests/blink-white.c
@@ -5,6 +5,9 @@
 #define DELAY 400000
 
 #include "embedded_types.h"
+#include "isr.h"
+
+no_isrs();
 
 __attribute__ ((section ("startup")))
 void main(void) {
diff --git a/tests/nvm-read.c b/tests/nvm-read.c
index efbd22f64..12c2e44cc 100644
--- a/tests/nvm-read.c
+++ b/tests/nvm-read.c
@@ -29,6 +29,10 @@ void put_hex32(uint32_t x);
 const uint8_t hex[16]={'0','1','2','3','4','5','6','7',
 		 '8','9','a','b','c','d','e','f'};
 
+#include "isr.h"
+
+no_isrs();
+
 #define NBYTES 1024
 __attribute__ ((section ("startup")))
 void main(void) {
diff --git a/tests/rftest-rx.c b/tests/rftest-rx.c
index aeecbb35e..fb91e349e 100644
--- a/tests/rftest-rx.c
+++ b/tests/rftest-rx.c
@@ -77,6 +77,9 @@ void toggle_led(void) {
 	}
 }
 
+#include "isr.h"
+no_isrs();
+
 __attribute__ ((section ("startup")))
 void main(void) {
 	uint8_t c;
diff --git a/tests/rftest-tx.c b/tests/rftest-tx.c
index de688bdef..b6f607934 100644
--- a/tests/rftest-tx.c
+++ b/tests/rftest-tx.c
@@ -112,6 +112,9 @@ void fill_data(void) {
 	}		
 }
 
+#include "isr.h"
+no_isrs();
+
 __attribute__ ((section ("startup")))
 void main(void) {
 	uint8_t c;
diff --git a/tests/romimg.c b/tests/romimg.c
index 51ba68d8b..5b2d346eb 100644
--- a/tests/romimg.c
+++ b/tests/romimg.c
@@ -28,6 +28,9 @@ const uint8_t hex[16]={'0','1','2','3','4','5','6','7',
 #define DUMP_LEN  0x00014000
 //#define DUMP_LEN  16
 
+#include "isr.h"
+no_isrs();
+
 __attribute__ ((section ("startup")))
 void main(void) {
 	volatile uint32_t i;
diff --git a/tests/tmr-ints.c b/tests/tmr-ints.c
index 22c12a75d..acb324c64 100644
--- a/tests/tmr-ints.c
+++ b/tests/tmr-ints.c
@@ -47,12 +47,40 @@
 #define reg16(x) (*(volatile uint16_t *)(x))
 
 #include "embedded_types.h"
+#include "sys-interrupt.h"
+
+#include "isr.h"
+
+volatile uint8_t led;
+
+#define LED_VAL 0x00000300
+#define led_init() do { reg32(GPIO_PAD_DIR0) = LED_VAL; } while(0);
+#define led_on() do  { led = 1; reg32(GPIO_DATA0) = LED_VAL; } while(0);
+#define led_off() do { led = 0; reg32(GPIO_DATA0) = 0x00000000; } while(0);
+
+void toggle_led(void) {
+	if(0 == led) {
+		led_on();
+		led = 1;
+
+	} else {
+		led_off();
+	}
+}
+
+void tmr_isr(void) {
+
+	toggle_led();
+	reg16(TMR0_SCTRL) = 0;
+	reg16(TMR0_CSCTRL) = 0x0040; /* clear compare flag */
+	
+}
 
 __attribute__ ((section ("startup")))
 void main(void) {
 
 	/* pin direction */
-	reg32(GPIO_PAD_DIR0) = 0x00000400;
+	led_init();
 
 	/* timer setup */
 	/* CTRL */
@@ -66,7 +94,8 @@ void main(void) {
 #define OUT_MODE   0      /* OFLAG is asserted while counter is active */
 
 	reg16(TMR_ENBL) = 0;                     /* tmrs reset to enabled */
-	reg16(TMR0_SCTRL) = 0;
+	reg16(TMR0_SCTRL) = 0;  
+	reg16(TMR0_CSCTRL) =0x0040;  
 	reg16(TMR0_LOAD) = 0;                    /* reload to zero */
 	reg16(TMR0_COMP_UP) = 18750;             /* trigger a reload at the end */
 	reg16(TMR0_CMPLD1) = 18750;              /* compare 1 triggered reload level, 10HZ maybe? */
@@ -74,19 +103,12 @@ void main(void) {
 	reg16(TMR0_CTRL) = (COUNT_MODE<<13) | (PRIME_SRC<<9) | (SEC_SRC<<7) | (ONCE<<6) | (LEN<<5) | (DIR<<4) | (CO_INIT<<3) | (OUT_MODE);
 	reg16(TMR_ENBL) = 0xf;                   /* enable all the timers --- why not? */
 
+	led_on();
+
+	enable_tmr_irq();
+	enableIRQ();
+
 	while(1) {
-
-		/* blink on */
-		reg32(GPIO_DATA0) = 0x00000400;
-		
-		while((reg16(TMR0_SCTRL)>>15) == 0) { continue; }
-		reg16(TMR0_SCTRL) = 0; /*clear bit 15, and all the others --- should be ok, but clearly not "the right thing to do" */
-
-		/* blink off */
-		reg32(GPIO_DATA0) = 0x00000000;
-
-		while((reg16(TMR0_SCTRL)>>15) == 0) { continue; }
-		reg16(TMR0_SCTRL) = 0; /*clear bit 15, and all the others --- should be ok, but clearly not "the right thing to do" */
-
+		/* sit here and let the interrupts do the work */
 	};
 }
diff --git a/tests/tmr.c b/tests/tmr.c
index 22c12a75d..d09912e63 100644
--- a/tests/tmr.c
+++ b/tests/tmr.c
@@ -48,6 +48,9 @@
 
 #include "embedded_types.h"
 
+#include "isr.h"
+no_isrs();
+
 __attribute__ ((section ("startup")))
 void main(void) {
 
diff --git a/tests/uart1-loopback.c b/tests/uart1-loopback.c
index ce516d7ad..b3eec3940 100644
--- a/tests/uart1-loopback.c
+++ b/tests/uart1-loopback.c
@@ -11,6 +11,9 @@
 
 #include "embedded_types.h"
 
+#include "isr.h"
+no_isrs();
+
 __attribute__ ((section ("startup")))
 void main(void) {
 	/* Restore UART regs. to default */

From 10fdafbcb2dfdb87af5aadea13f0138b85891d59 Mon Sep 17 00:00:00 2001
From: Mariano Alvira <mar@devl.org>
Date: Mon, 20 Apr 2009 18:38:45 -0400
Subject: [PATCH 07/10] initial isr. has problems.

---
 include/isr.h | 22 ++++++++++++++++++++++
 src/isr.c     | 20 ++++++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 include/isr.h
 create mode 100644 src/isr.c

diff --git a/include/isr.h b/include/isr.h
new file mode 100644
index 000000000..4939d42c4
--- /dev/null
+++ b/include/isr.h
@@ -0,0 +1,22 @@
+#ifndef ISR_H
+#define ISR_H
+
+#include "embedded_types.h"
+
+#define INTBASE (0x80020000)
+#define INTENNUM_OFF (0x8)
+#define INTSRC_OFF (0x30)
+
+#define INTENNUM INTBASE + INTENNUM_OFF
+#define INTSRC   INTBASE + INTSRC_OFF 
+
+
+#define no_isrs() no_tmr_isr();
+
+#define enable_tmr_irq() *(volatile uint32_t *)(INTENNUM)
+#define no_tmr_isr() void tmr_isr(void) { return; }
+
+extern void tmr_isr(void);
+
+#endif
+
diff --git a/src/isr.c b/src/isr.c
new file mode 100644
index 000000000..5b27130a0
--- /dev/null
+++ b/src/isr.c
@@ -0,0 +1,20 @@
+#include "embedded_types.h"
+#include "interrupt-utils.h"
+#include "isr.h"
+
+#define reg32(x) (*(volatile uint32_t *)(x))
+
+__attribute__ ((interrupt("IRQ"))) 
+void isr(void)
+{
+//	ISR_ENTRY();
+	/* check for TMR0 interrupt */
+//	tmr_isr(); // led turns off if I have this, indicating that the isr does jump to tmr_isr
+//	if(reg32(INTSRC) & (1<<5)) { tmr_isr(); }
+//	asm("SUBS PC,R14_IRQ,#4")
+//	enableIRQ(); // I think this is necessary, but the LED never turns off when I have this
+//	ISR_EXIT();  // behavior doesn't change if I have this or not. 
+
+/* putting anything in here breaks the other code :( */
+
+}

From bdbf279d0f8d9b3f470be5150f33e4c9b0bade3a Mon Sep 17 00:00:00 2001
From: Mariano Alvira <mar@devl.org>
Date: Wed, 22 Apr 2009 14:55:40 -0400
Subject: [PATCH 08/10] tmr imts works. I'm not thrilled with how the
 interrupts and modes are set... but I'm not sure what to do about it. The big
 problem is that I have to be in user mode to service irqs, but I can't enable
 and disable F and I in usermode. All I can do is an swi and then have handler
 which lets me enable or disable them (like a mini-syscall).

---
 Makefile         |   6 +--
 config.mk        |   2 +-
 include/isr.h    |   2 +-
 src/isr.c        |   8 ++--
 src/start.S      | 112 +++++++++++++++++++++++++++++------------------
 tests/tmr-ints.c |  22 ++++++++--
 6 files changed, 98 insertions(+), 54 deletions(-)

diff --git a/Makefile b/Makefile
index dc29499dc..1f12d73dd 100644
--- a/Makefile
+++ b/Makefile
@@ -63,14 +63,14 @@ all:		src/start.o src/isr.o $(ALL)
 tests/nvm-read.obj: src/maca.o src/nvm.o
 tests/rftest-rx.obj: src/maca.o src/nvm.o
 tests/rftest-tx.obj: src/maca.o src/nvm.o
-tests/tmr-ints.obj: src/interrupt-utils.o src/sys-interrupt.o src/isr.o
+tests/tmr-ints.obj: src/isr.o
 
 NOTHUMB_CPPFLAGS := $(DBGFLAGS) $(OPTFLAGS) $(RELFLAGS)         \
         -D__KERNEL__ -DTEXT_BASE=$(TEXT_BASE)           \
         -I$(TOPDIR)/include                             \
         -fno-builtin -ffreestanding -nostdinc -isystem  \
         $(gccincdir) -pipe 
-NOTHUMB_CPPFLAGS_EXTRA = -march=armv4t -mlong-calls -mthumb-interwork -mtune=arm7tdmi-s -DCONFIG_ARM -D__ARM__
+NOTHUMB_CPPFLAGS_EXTRA = -march=armv4t -mlong-calls -mtune=arm7tdmi-s -DCONFIG_ARM -D__ARM__ #-mthumb-interwork 
 
 
 src/isr.o: src/isr.c
@@ -88,7 +88,7 @@ src/isr.o: src/isr.c
 %.dis:		%.obj
 		$(OBJDUMP) -SD $< > $@
 
-%.obj:		$(LDSCRIPT) %.o src/interrupt-utils.o
+%.obj:		$(LDSCRIPT) %.o #src/interrupt-utils.o
 		$(LD) $(LDFLAGS) $(AOBJS) \
 			--start-group $(PLATFORM_LIBS) --end-group \
 			-Map $*.map $^ -o $@
diff --git a/config.mk b/config.mk
index 3fb973e44..b5f092959 100644
--- a/config.mk
+++ b/config.mk
@@ -26,7 +26,7 @@
 # clean the slate ...
 PLATFORM_LDFLAGS =
 PLATFORM_RELFLAGS = -fno-strict-aliasing  -fno-common -ffixed-r8 -ffunction-sections -msoft-float
-PLATFORM_CPPFLAGS = -march=armv4t -mlong-calls -mcallee-super-interworking -mthumb -mthumb-interwork -mtune=arm7tdmi-s -DCONFIG_ARM -D__ARM__
+PLATFORM_CPPFLAGS = -march=armv4t -mlong-calls -mtune=arm7tdmi-s -DCONFIG_ARM -D__ARM__ #-mcallee-super-interworking -mthumb -mthumb-interwork
 TEXT_BASE = 0x00400000
 
 #########################################################################
diff --git a/include/isr.h b/include/isr.h
index 4939d42c4..0583ffc7e 100644
--- a/include/isr.h
+++ b/include/isr.h
@@ -13,7 +13,7 @@
 
 #define no_isrs() no_tmr_isr();
 
-#define enable_tmr_irq() *(volatile uint32_t *)(INTENNUM)
+#define enable_tmr_irq() *(volatile uint32_t *)(INTENNUM) = 5;
 #define no_tmr_isr() void tmr_isr(void) { return; }
 
 extern void tmr_isr(void);
diff --git a/src/isr.c b/src/isr.c
index 5b27130a0..913374208 100644
--- a/src/isr.c
+++ b/src/isr.c
@@ -1,15 +1,15 @@
 #include "embedded_types.h"
-#include "interrupt-utils.h"
+//#include "interrupt-utils.h"
 #include "isr.h"
 
 #define reg32(x) (*(volatile uint32_t *)(x))
 
-__attribute__ ((interrupt("IRQ"))) 
+//__attribute__ ((interrupt("IRQ"))) 
 void isr(void)
 {
 //	ISR_ENTRY();
 	/* check for TMR0 interrupt */
-//	tmr_isr(); // led turns off if I have this, indicating that the isr does jump to tmr_isr
+	tmr_isr(); // led turns off if I have this, indicating that the isr does jump to tmr_isr
 //	if(reg32(INTSRC) & (1<<5)) { tmr_isr(); }
 //	asm("SUBS PC,R14_IRQ,#4")
 //	enableIRQ(); // I think this is necessary, but the LED never turns off when I have this
@@ -17,4 +17,6 @@ void isr(void)
 
 /* putting anything in here breaks the other code :( */
 
+//	asm("ldmfd sp!, {r0-r12,lr}");
+//	enableIRQ();
 }
diff --git a/src/start.S b/src/start.S
index 2e17e424e..cbed1189a 100644
--- a/src/start.S
+++ b/src/start.S
@@ -23,15 +23,33 @@
  * MA 02111-1307 USA
  */
 
+/* Standard definitions of Mode bits and Interrupt (I & F) flags in PSRs */
+	
+	.equ    I_BIT,          0x80      /* when I bit is set, IRQ is disabled */
+	.equ    F_BIT,          0x40      /* when F bit is set, FIQ is disabled */
+	
+	.equ    USR_MODE,       0x10
+	.equ    FIQ_MODE,       0x11
+	.equ    IRQ_MODE,       0x12
+	.equ    SVC_MODE,       0x13
+	.equ    ABT_MODE,       0x17
+	.equ    UND_MODE,       0x1B
+	.equ    SYS_MODE,       0x1F
 
+	.equ    usr_stack_size, 256*4
+	.equ    irq_stack_size, 128*4
+	.equ    fiq_stack_size, 128*4
+	.equ    und_stack_size,  32*4
+	.equ    abt_stack_size,  32*4
+	.equ    sup_stack_size,  32*4
+	
 /*
  *************************************************************************
  *
  * Jump vector table as in table 3.1 in [1]
  *
  *************************************************************************
- */
-
+ */	
 
 .set base, .
 .set _rom_data_init, 0x108d0
@@ -72,7 +90,37 @@ ROM_var_end:   .word 0
 .code 32
 .align
 _begin:
+
+ 	ldr     r1,=_system_stack
+ 	msr     cpsr_c,#(SVC_MODE | I_BIT | F_BIT)
+ 	add     r1,r1,#sup_stack_size
+ 	mov     sp,r1
+
+ 	msr     cpsr_c,#(IRQ_MODE | I_BIT | F_BIT)
+ 	add     r1,r1,#irq_stack_size
+ 	mov     sp,r1
+
+ 	msr     cpsr_c,#(FIQ_MODE | I_BIT | F_BIT)
+ 	add     r1,r1,#fiq_stack_size
+ 	mov     sp,r1
+	
+ 	msr     cpsr_c,#(ABT_MODE | I_BIT | F_BIT)
+ 	add     r1,r1,#abt_stack_size
+ 	mov     sp,r1
+
+ 	msr     cpsr_c,#(UND_MODE | I_BIT | F_BIT)
+ 	add     r1,r1,#und_stack_size
+ 	mov     sp,r1
+
+// 	msr     cpsr_c,#(USR_MODE | I_BIT | F_BIT)
+// 	add     r1,r1,#usr_stack_size
+// 	mov     sp,r1
+
+
 	bl _rom_data_init+.-base
+	msr     cpsr_c,#(SVC_MODE) // turn on interrupts --- for debug only	
+ 	msr     cpsr_c,#(USR_MODE) // turn on interrupts --- for debug only
+//	swi
 	b main
 	
 _undefined_instruction:	.word undefined_instruction
@@ -82,9 +130,8 @@ _data_abort:		.word data_abort
 _not_used:		.word not_used
 _irq:			.word irq
 _fiq:			.word fiq
-	.balignl 16,0xdeadbeef
-
-
+	.balignl 16,0xdeadbeef	
+	
 /*
  *************************************************************************
  *
@@ -105,6 +152,10 @@ _TEXT_BASE:
 _armboot_start:
 	.word _start
 
+_system_stack:
+	. = . + usr_stack_size + irq_stack_size + fiq_stack_size + und_stack_size + abt_stack_size + sup_stack_size
+
+	
 /*
  * These are defined in the board-specific linker script.
  */
@@ -118,6 +169,8 @@ _bss_end:
 
 _start_armboot: .word main
 
+
+	
 /*
  *************************************************************************
  *
@@ -139,42 +192,6 @@ cpu_init_crit:
  *************************************************************************
  */
 
-@
-@ IRQ stack frame.
-@
-#define S_FRAME_SIZE	72
-
-#define S_OLD_R0	68
-#define S_PSR		64
-#define S_PC		60
-#define S_LR		56
-#define S_SP		52
-
-#define S_IP		48
-#define S_FP		44
-#define S_R10		40
-#define S_R9		36
-#define S_R8		32
-#define S_R7		28
-#define S_R6		24
-#define S_R5		20
-#define S_R4		16
-#define S_R3		12
-#define S_R2		8
-#define S_R1		4
-#define S_R0		0
-
-#define MODE_SVC 0x13
-#define I_BIT	 0x80
-
-
-	.macro get_irq_stack			@ setup IRQ stack
-	ldr	sp, IRQ_STACK_START
-	.endm
-
-	.macro get_fiq_stack			@ setup FIQ stack
-	ldr	sp, FIQ_STACK_START
-	.endm
 
 /*
  * exception handlers
@@ -197,8 +214,18 @@ not_used:
 
 	.align	5
 irq:
+	push	{lr}
+	movs    lr,pc
 	b isr
-	.align	5
+	pop     {lr}
+	subs 	pc,r14,#4 // suggested irq return cmd
+//	STMFD    sp!, {r0-r12,lr}
+//	MOVNE 	 lr,pc
+//	ldr 	r0, =isr
+//	BX      r0
+//	LDMFD    r13!, {r0-r12,r14}
+//	MOVS     PC, R14
+//	subs 	pc, r14, #4
 fiq:
 
 	.align	5
@@ -206,3 +233,4 @@ fiq:
 .globl reset_cpu
 reset_cpu:
 	mov     pc, r0
+
diff --git a/tests/tmr-ints.c b/tests/tmr-ints.c
index acb324c64..1fc7fe024 100644
--- a/tests/tmr-ints.c
+++ b/tests/tmr-ints.c
@@ -47,7 +47,7 @@
 #define reg16(x) (*(volatile uint16_t *)(x))
 
 #include "embedded_types.h"
-#include "sys-interrupt.h"
+//#include "sys-interrupt.h"
 
 #include "isr.h"
 
@@ -76,9 +76,22 @@ void tmr_isr(void) {
 	
 }
 
+
+/* void enIRQ(void) { */
+/* 	asm volatile ( */
+/* 		".code 32;" */
+/* 		"msr     cpsr_c,#0x10;"  */
+/* 		".code 16;" */
+/* 		); */
+/* } */
+
+
 __attribute__ ((section ("startup")))
 void main(void) {
 
+//	*(volatile uint32_t *)0x80020010 = 0x20;
+//	*(volatile uint32_t *)0x80020034 = 0xffff; //force an int.
+ 
 	/* pin direction */
 	led_init();
 
@@ -94,8 +107,8 @@ void main(void) {
 #define OUT_MODE   0      /* OFLAG is asserted while counter is active */
 
 	reg16(TMR_ENBL) = 0;                     /* tmrs reset to enabled */
-	reg16(TMR0_SCTRL) = 0;  
-	reg16(TMR0_CSCTRL) =0x0040;  
+	reg16(TMR0_SCTRL) = 0;
+	reg16(TMR0_CSCTRL) =0x0040;
 	reg16(TMR0_LOAD) = 0;                    /* reload to zero */
 	reg16(TMR0_COMP_UP) = 18750;             /* trigger a reload at the end */
 	reg16(TMR0_CMPLD1) = 18750;              /* compare 1 triggered reload level, 10HZ maybe? */
@@ -106,7 +119,8 @@ void main(void) {
 	led_on();
 
 	enable_tmr_irq();
-	enableIRQ();
+
+//	enIRQ();
 
 	while(1) {
 		/* sit here and let the interrupts do the work */

From 9f31e40864c81cb018fbc60c7805cc5b6822cf31 Mon Sep 17 00:00:00 2001
From: Mariano Alvira <mar@devl.org>
Date: Wed, 22 Apr 2009 15:14:04 -0400
Subject: [PATCH 09/10] only go into usermode in the interrupt test... still
 sorting out the best way to handle this.

---
 src/start.S      | 1 -
 tests/tmr-ints.c | 4 ++++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/start.S b/src/start.S
index cbed1189a..683e79226 100644
--- a/src/start.S
+++ b/src/start.S
@@ -119,7 +119,6 @@ _begin:
 
 	bl _rom_data_init+.-base
 	msr     cpsr_c,#(SVC_MODE) // turn on interrupts --- for debug only	
- 	msr     cpsr_c,#(USR_MODE) // turn on interrupts --- for debug only
 //	swi
 	b main
 	
diff --git a/tests/tmr-ints.c b/tests/tmr-ints.c
index 1fc7fe024..f72222f40 100644
--- a/tests/tmr-ints.c
+++ b/tests/tmr-ints.c
@@ -122,6 +122,10 @@ void main(void) {
 
 //	enIRQ();
 
+	/* go into user mode to handle IRQs */
+	/* disabling interrupts is now difficult */
+ 	asm("msr     cpsr_c,#(0x10)");
+
 	while(1) {
 		/* sit here and let the interrupts do the work */
 	};

From 8964c60d9a62a93e06e6c493b9126c6cd16a678a Mon Sep 17 00:00:00 2001
From: Mariano Alvira <mar@devl.org>
Date: Wed, 22 Apr 2009 16:04:50 -0400
Subject: [PATCH 10/10] enabling thumb only enter user mode in tmr-ints.

usermode breaks rftests.
---
 Makefile         |  2 +-
 config.mk        |  2 +-
 src/start.S      | 10 +++++-----
 tests/tmr-ints.c |  6 ++++--
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/Makefile b/Makefile
index 1f12d73dd..4803b5e1b 100644
--- a/Makefile
+++ b/Makefile
@@ -70,7 +70,7 @@ NOTHUMB_CPPFLAGS := $(DBGFLAGS) $(OPTFLAGS) $(RELFLAGS)         \
         -I$(TOPDIR)/include                             \
         -fno-builtin -ffreestanding -nostdinc -isystem  \
         $(gccincdir) -pipe 
-NOTHUMB_CPPFLAGS_EXTRA = -march=armv4t -mlong-calls -mtune=arm7tdmi-s -DCONFIG_ARM -D__ARM__ #-mthumb-interwork 
+NOTHUMB_CPPFLAGS_EXTRA = -march=armv4t -mlong-calls -mtune=arm7tdmi-s -DCONFIG_ARM -D__ARM__ -mthumb-interwork 
 
 
 src/isr.o: src/isr.c
diff --git a/config.mk b/config.mk
index b5f092959..c21f9b280 100644
--- a/config.mk
+++ b/config.mk
@@ -26,7 +26,7 @@
 # clean the slate ...
 PLATFORM_LDFLAGS =
 PLATFORM_RELFLAGS = -fno-strict-aliasing  -fno-common -ffixed-r8 -ffunction-sections -msoft-float
-PLATFORM_CPPFLAGS = -march=armv4t -mlong-calls -mtune=arm7tdmi-s -DCONFIG_ARM -D__ARM__ #-mcallee-super-interworking -mthumb -mthumb-interwork
+PLATFORM_CPPFLAGS = -march=armv4t -mlong-calls -mtune=arm7tdmi-s -DCONFIG_ARM -D__ARM__ -mcallee-super-interworking -mthumb -mthumb-interwork
 TEXT_BASE = 0x00400000
 
 #########################################################################
diff --git a/src/start.S b/src/start.S
index 683e79226..bc991ad7d 100644
--- a/src/start.S
+++ b/src/start.S
@@ -113,13 +113,13 @@ _begin:
  	mov     sp,r1
 
 // 	msr     cpsr_c,#(USR_MODE | I_BIT | F_BIT)
-// 	add     r1,r1,#usr_stack_size
-// 	mov     sp,r1
-
 
 	bl _rom_data_init+.-base
-	msr     cpsr_c,#(SVC_MODE) // turn on interrupts --- for debug only	
-//	swi
+	msr     cpsr_c,#(SVC_MODE) // turn on interrupts --- for debug only
+//	msr     cpsr_c,#(USR_MODE) // turn on interrupts --- for debug only		
+// 	add     r1,r1,#usr_stack_size
+// 	mov     sp,r1
+	
 	b main
 	
 _undefined_instruction:	.word undefined_instruction
diff --git a/tests/tmr-ints.c b/tests/tmr-ints.c
index f72222f40..e93b142e1 100644
--- a/tests/tmr-ints.c
+++ b/tests/tmr-ints.c
@@ -124,8 +124,10 @@ void main(void) {
 
 	/* go into user mode to handle IRQs */
 	/* disabling interrupts is now difficult */
- 	asm("msr     cpsr_c,#(0x10)");
-
+ 	asm(".code 32;"
+	    "msr     cpsr_c,#(0x10);"
+	    ".code 16; ");
+	
 	while(1) {
 		/* sit here and let the interrupts do the work */
 	};