Retro68/gcc/libgloss/bfin/basiccrt.S
2012-03-27 01:51:53 +02:00

587 lines
14 KiB
ArmAsm

/*
* Basic startup code for Blackfin processor
*
* Copyright (C) 2008 Analog Devices, Inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice is included verbatim in any distributions. No written agreement,
* license, or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their authors
* and need not follow the licensing terms described here, provided that
* the new terms are clearly indicated on the first page of each file where
* they apply.
*/
// basic startup code which
// - turns the cycle counter on
// - loads up FP & SP (both supervisor and user)
// - initialises the device drivers (FIOCRT)
// - calls monstartup to set up the profiling routines (PROFCRT)
// - calls the C++ startup (CPLUSCRT)
// - initialises argc/argv (FIOCRT/normal)
// - calls _main
// - calls _exit (which calls monexit to dump accumulated prof data (PROFCRT))
// - defines dummy IO routines (!FIOCRT)
#include <sys/platform.h>
#include <cplb.h>
#include <sys/anomaly_macros_rtl.h>
#define IVBh (EVT0 >> 16)
#define IVBl (EVT0 & 0xFFFF)
#define UNASSIGNED_VAL 0
#define UNASSIGNED_FILL 0
// just IVG15
#define INTERRUPT_BITS 0x400
#if defined(_ADI_THREADS) || \
!defined(__ADSPLPBLACKFIN__) || defined(__ADSPBF561__) || defined(__ADSPBF566__)
#define SET_CLOCK_SPEED 0
#else
#define SET_CLOCK_SPEED 1
#endif
#if SET_CLOCK_SPEED == 1
#include <sys/pll.h>
#define SET_CLK_MSEL 0x16
#define SET_CLK_DF 0
#define SET_CLK_LOCK_COUNT 0x300
#define SET_CLK_CSEL 0
#define SET_CLK_SSEL 5
/*
** CLKIN == 27MHz on the EZ-Kits.
** D==0 means CLKIN is passed to PLL without dividing.
** MSEL==0x16 means VCO==27*0x16 == 594MHz
** CSEL==0 means CCLK==VCO == 594MHz
** SSEL==5 means SCLK==VCO/5 == 118MHz
*/
#endif
#ifdef __ADSPBF561_COREB__
.section .b.text,"ax",@progbits
.align 2;
.global __coreb_start;
.type __coreb_start, STT_FUNC;
__coreb_start:
#else
.text;
.align 2;
.global __start;
.type __start, STT_FUNC;
__start:
#endif
#if WA_05000109
// Avoid Anomaly ID 05000109.
# define SYSCFG_VALUE 0x30
R1 = SYSCFG_VALUE;
SYSCFG = R1;
#endif
#if WA_05000229
// Avoid Anomaly 05-00-0229: DMA5_CONFIG and SPI_CTL not cleared on reset.
R1 = 0x400;
#if defined(__ADSPBF538__) || defined(__ADSPBF539__)
P0.L = SPI0_CTL & 0xFFFF;
P0.H = SPI0_CTL >> 16;
W[P0] = R1.L;
#else
P0.L = SPI_CTL & 0xFFFF;
P0.H = SPI_CTL >> 16;
W[P0] = R1.L;
#endif
P0.L = DMA5_CONFIG & 0xFFFF;
P0.H = DMA5_CONFIG >> 16;
R1 = 0;
W[P0] = R1.L;
#endif
// Zap loop counters to zero, to make sure that
// hw loops are disabled - it could be really baffling
// if the counters and bottom regs are set, and we happen
// to run into them.
R7 = 0;
LC0 = R7;
LC1 = R7;
// Clear the DAG Length regs too, so that it's safe to
// use I-regs without them wrapping around.
L0 = R7;
L1 = R7;
L2 = R7;
L3 = R7;
// Zero ITEST_COMMAND and DTEST_COMMAND
// (in case they have crud in them and
// does a write somewhere when we enable cache)
I0.L = (ITEST_COMMAND & 0xFFFF);
I0.H = (ITEST_COMMAND >> 16);
I1.L = (DTEST_COMMAND & 0xFFFF);
I1.H = (DTEST_COMMAND >> 16);
R7 = 0;
[I0] = R7;
[I1] = R7;
// It seems writing ITEST_COMMAND from SDRAM with icache enabled
// needs SSYNC.
#ifdef __BFIN_SDRAM
SSYNC;
#else
CSYNC;
#endif
// Initialise the Event Vector table.
P0.H = IVBh;
P0.L = IVBl;
// Install __unknown_exception_occurred in EVT so that
// there is defined behaviour.
P0 += 2*4; // Skip Emulation and Reset
P1 = 13;
R1.L = __unknown_exception_occurred;
R1.H = __unknown_exception_occurred;
LSETUP (L$ivt,L$ivt) LC0 = P1;
L$ivt: [P0++] = R1;
// Set IVG15's handler to be the start of the mode-change
// code. Then, before we return from the Reset back to user
// mode, we'll raise IVG15. This will mean we stay in supervisor
// mode, and continue from the mode-change point., but at a
// much lower priority.
P1.H = L$supervisor_mode;
P1.L = L$supervisor_mode;
[P0] = P1;
// Initialise the stack.
// Note: this points just past the end of the section.
// First write should be with [--SP].
#ifdef __BFIN_SDRAM
SP.L = __end + 0x400000 - 12;
SP.H = __end + 0x400000 - 12;
#else
#ifdef __ADSPBF561_COREB__
SP.L=__coreb_stack_end - 12;
SP.H=__coreb_stack_end - 12;
#else
SP.L=__stack_end - 12;
SP.H=__stack_end - 12;
#endif
#endif
usp = sp;
// We're still in supervisor mode at the moment, so the FP
// needs to point to the supervisor stack.
FP = SP;
// And make space for incoming "parameters" for functions
// we call from here:
SP += -12;
// Zero out bss section
#ifdef __BFIN_SDRAM
R0.L = ___bss_start;
R0.H = ___bss_start;
R1.L = __end;
R1.H = __end;
#else
#ifdef __ADSPBF561_COREB__
R0.L = __coreb_bss_start;
R0.H = __coreb_bss_start;
R1.L = __coreb_bss_end;
R1.H = __coreb_bss_end;
#else
R0.L = __bss_start;
R0.H = __bss_start;
R1.L = __bss_end;
R1.H = __bss_end;
#endif
#endif
R2 = R1 - R0;
R1 = 0;
#ifdef __ADSPBF561_COREB__
CALL.X __coreb_memset;
#else
CALL.X _memset;
#endif
R0 = INTERRUPT_BITS;
R0 <<= 5; // Bits 0-4 not settable.
// CALL.X __install_default_handlers;
R4 = R0; // Save modified list
R0 = SYSCFG; // Enable the Cycle counter
BITSET(R0,1);
SYSCFG = R0;
#if WA_05000137
// Avoid anomaly #05000137
// Set the port preferences of DAG0 and DAG1 to be
// different; this gives better performance when
// performing dual-dag operations on SDRAM.
P0.L = DMEM_CONTROL & 0xFFFF;
P0.H = DMEM_CONTROL >> 16;
R0 = [P0];
BITSET(R0, 12);
BITCLR(R0, 13);
[P0] = R0;
CSYNC;
#endif
// Reinitialise data areas in RAM from ROM, if MemInit's
// been used.
// CALL.X _mi_initialize;
#if defined(__ADSPLPBLACKFIN__)
#if SET_CLOCK_SPEED == 1
#if 0
// Check if this feature is enabled, i.e. ___clk_ctrl is defined to non-zero
P0.L = ___clk_ctrl;
P0.H = ___clk_ctrl;
R0 = MAX_IN_STARTUP;
R1 = [P0];
R0 = R0 - R1;
CC = R0;
IF CC JUMP L$clock_is_set;
#endif
// Investigate whether we are a suitable revision
// for boosting the system clocks.
// speed.
P0.L = DSPID & 0xFFFF;
P0.H = DSPID >> 16;
R0 = [P0];
R0 = R0.L (Z);
CC = R0 < 2;
IF CC JUMP L$clock_is_set;
// Set the internal Voltage-Controlled Oscillator (VCO)
R0 = SET_CLK_MSEL (Z);
R1 = SET_CLK_DF (Z);
R2 = SET_CLK_LOCK_COUNT (Z);
CALL.X __pll_set_system_vco;
// Set the Core and System clocks
R0 = SET_CLK_CSEL (Z);
R1 = SET_CLK_SSEL (Z);
CALL.X __pll_set_system_clocks;
L$clock_is_set:
#endif
#endif /* ADSPLPBLACKFIN */
#if defined(__ADSPBF561__) || defined(__ADSPBF566__)
// Initialise the multi-core data tables.
// A dummy function will be called if we are not linking with
// -multicore
// CALL.X __mc_data_initialise;
#endif
#if 0
// Write the cplb exception handler to the EVT if approprate and
// initialise the CPLBs if they're needed. couldn't do
// this before we set up the stacks.
P2.H = ___cplb_ctrl;
P2.L = ___cplb_ctrl;
R0 = CPLB_ENABLE_ANY_CPLBS;
R6 = [P2];
R0 = R0 & R6;
CC = R0;
IF !CC JUMP L$no_cplbs;
#if !defined(_ADI_THREADS)
P1.H = __cplb_hdr;
P1.L = __cplb_hdr;
P0.H = IVBh;
P0.L = IVBl;
[P0+12] = P1; // write exception handler
#endif /* _ADI_THREADS */
R0 = R6;
CALL.X __cplb_init;
#endif
L$no_cplbs:
// Enable interrupts
STI R4; // Using the mask from default handlers
RAISE 15;
// Move the processor into user mode.
P0.L=L$still_interrupt_in_ipend;
P0.H=L$still_interrupt_in_ipend;
RETI=P0;
L$still_interrupt_in_ipend:
rti; // keep doing 'rti' until we've 'finished' servicing all
// interrupts of priority higher than IVG15. Normally one
// would expect to only have the reset interrupt in IPEND
// being serviced, but occasionally when debugging this may
// not be the case - if restart is hit when servicing an
// interrupt.
//
// When we clear all bits from IPEND, we'll enter user mode,
// then we'll automatically jump to supervisor_mode to start
// servicing IVG15 (which we will 'service' for the whole
// program, so that the program is in supervisor mode.
//
// Need to do this to 'finish' servicing the reset interupt.
L$supervisor_mode:
[--SP] = RETI; // re-enables the interrupt system
R0.L = UNASSIGNED_VAL;
R0.H = UNASSIGNED_VAL;
#if UNASSIGNED_FILL
R2=R0;
R3=R0;
R4=R0;
R5=R0;
R6=R0;
R7=R0;
P0=R0;
P1=R0;
P2=R0;
P3=R0;
P4=R0;
P5=R0;
#endif
// Push a RETS and Old FP onto the stack, for sanity.
[--SP]=R0;
[--SP]=R0;
// Make sure the FP is sensible.
FP = SP;
// And leave space for incoming "parameters"
SP += -12;
#ifdef PROFCRT
CALL.X monstartup; // initialise profiling routines
#endif /* PROFCRT */
#ifndef __ADSPBF561_COREB__
CALL.X __init;
R0.L = __fini;
R0.H = __fini;
CALL.X _atexit;
#endif
#if !defined(_ADI_THREADS)
#ifdef FIOCRT
// FILE IO provides access to real command-line arguments.
CALL.X __getargv;
r1.l=__Argv;
r1.h=__Argv;
#else
// Default to having no arguments and a null list.
R0=0;
#ifdef __ADSPBF561_COREB__
R1.L=L$argv_coreb;
R1.H=L$argv_coreb;
#else
R1.L=L$argv;
R1.H=L$argv;
#endif
#endif /* FIOCRT */
#endif /* _ADI_THREADS */
// At long last, call the application program.
#ifdef __ADSPBF561_COREB__
CALL.X _coreb_main;
#else
CALL.X _main;
#endif
#if !defined(_ADI_THREADS)
#ifndef __ADSPBF561_COREB__
CALL.X _exit; // passing in main's return value
#endif
#endif
#ifdef __ADSPBF561_COREB__
.size __coreb_start, .-__coreb_start
#else
.size __start, .-__start
#endif
.align 2
.type __unknown_exception_occurred, STT_FUNC;
__unknown_exception_occurred:
// This function is invoked by the default exception
// handler, if it does not recognise the kind of
// exception that has occurred. In other words, the
// default handler only handles some of the system's
// exception types, and it does not expect any others
// to occur. If your application is going to be using
// other kinds of exceptions, you must replace the
// default handler with your own, that handles all the
// exceptions you will use.
//
// Since there's nothing we can do, we just loop here
// at what we hope is a suitably informative label.
IDLE;
CSYNC;
JUMP __unknown_exception_occurred;
RTS;
.size __unknown_exception_occurred, .-__unknown_exception_occurred
#if defined(__ADSPLPBLACKFIN__)
#if SET_CLOCK_SPEED == 1
/*
** CLKIN == 27MHz on the EZ-Kits.
** D==0 means CLKIN is passed to PLL without dividing.
** MSEL==0x16 means VCO==27*0x16 == 594MHz
** CSEL==0 means CCLK==VCO == 594MHz
** SSEL==5 means SCLK==VCO/5 == 118MHz
*/
// int pll_set_system_clocks(int csel, int ssel)
// returns 0 for success, -1 for error.
.align 2
.type __pll_set_system_clocks, STT_FUNC;
__pll_set_system_clocks:
P0.H = PLL_DIV >> 16;
P0.L = PLL_DIV & 0xFFFF;
R2 = W[P0] (Z);
// Plant CSEL and SSEL
R0 <<= 16;
R0.L = (4 << 8) | 2; // 2 bits, at posn 4
R1 <<= 16;
R1.L = 4; // 4 bits, at posn 0
R2 = DEPOSIT(R2, R0);
#if defined(__WORKAROUND_DREG_COMP_LATENCY)
// Work around anomaly 05-00-0209 which affects the DEPOSIT
// instruction (and the EXTRACT, SIGNBITS, and EXPADJ instructions)
// if the previous instruction created any of its operands
NOP;
#endif
R2 = DEPOSIT(R2, R1);
W[P0] = R2;
SSYNC;
RTS;
.size __pll_set_system_clocks, .-__pll_set_system_clocks
// int pll_set_system_vco(int msel, int df, lockcnt)
.align 2
.type __pll_set_system_vco, STT_FUNC;
__pll_set_system_vco:
P0.H = PLL_CTL >> 16;
P0.L = PLL_CTL & 0xFFFF;
R3 = W[P0] (Z);
P2 = R3; // Save copy
R3 >>= 1; // Drop old DF
R1 = ROT R1 BY -1; // Move DF into CC
R3 = ROT R3 BY 1; // and into ctl space.
R0 <<= 16; // Set up pattern reg
R0.L = (9<<8) | 6; // (6 bits at posn 9)
R1 = P2; // Get the old version
R3 = DEPOSIT(R3, R0);
CC = R1 == R3; // and if we haven't changed
IF CC JUMP L$done; // Anything, return
CC = R2 == 0; // Use default lockcount if
IF CC JUMP L$wakeup; // user one is zero.
P2.H = PLL_LOCKCNT >> 16;
P2.L = PLL_LOCKCNT & 0xFFFF;
W[P2] = R2; // Set the lock counter
L$wakeup:
P2.H = SIC_IWR >> 16;
P2.L = SIC_IWR & 0xFFFF;
R2 = [P2];
BITSET(R2, 0); // enable PLL Wakeup
[P2] = R2;
W[P0] = R3; // Update PLL_CTL
SSYNC;
CLI R2; // Avoid unnecessary interrupts
IDLE; // Wait until PLL has locked
STI R2; // Restore interrupts.
L$done:
RTS;
.size __pll_set_system_vco, .-__pll_set_system_vco
#endif
#endif /* ADSPLPBLACKFIN */
#ifdef __ADSPBF561_COREB__
.section .b.text,"ax",@progbits
.type __coreb_memset, STT_FUNC
__coreb_memset:
P0 = R0 ; /* P0 = address */
P2 = R2 ; /* P2 = count */
R3 = R0 + R2; /* end */
CC = R2 <= 7(IU);
IF CC JUMP .Ltoo_small;
R1 = R1.B (Z); /* R1 = fill char */
R2 = 3;
R2 = R0 & R2; /* addr bottom two bits */
CC = R2 == 0; /* AZ set if zero. */
IF !CC JUMP .Lforce_align ; /* Jump if addr not aligned. */
.Laligned:
P1 = P2 >> 2; /* count = n/4 */
R2 = R1 << 8; /* create quad filler */
R2.L = R2.L + R1.L(NS);
R2.H = R2.L + R1.H(NS);
P2 = R3;
LSETUP (.Lquad_loop , .Lquad_loop) LC0=P1;
.Lquad_loop:
[P0++] = R2;
CC = P0 == P2;
IF !CC JUMP .Lbytes_left;
RTS;
.Lbytes_left:
R2 = R3; /* end point */
R3 = P0; /* current position */
R2 = R2 - R3; /* bytes left */
P2 = R2;
.Ltoo_small:
CC = P2 == 0; /* Check zero count */
IF CC JUMP .Lfinished; /* Unusual */
.Lbytes:
LSETUP (.Lbyte_loop , .Lbyte_loop) LC0=P2;
.Lbyte_loop:
B[P0++] = R1;
.Lfinished:
RTS;
.Lforce_align:
CC = BITTST (R0, 0); /* odd byte */
R0 = 4;
R0 = R0 - R2;
P1 = R0;
R0 = P0; /* Recover return address */
IF !CC JUMP .Lskip1;
B[P0++] = R1;
.Lskip1:
CC = R2 <= 2; /* 2 bytes */
P2 -= P1; /* reduce count */
IF !CC JUMP .Laligned;
B[P0++] = R1;
B[P0++] = R1;
JUMP .Laligned;
.size __coreb_memset,.-__coreb_memset
#endif
#ifdef __ADSPBF561_COREB__
.section .b.bss,"aw",@progbits
.align 4
.type L$argv_coreb, @object
.size L$argv_coreb, 4
L$argv_coreb:
.zero 4
#else
.local L$argv
.comm L$argv,4,4
#endif