From 344a1b9eb8691af52de15a44ec70d8f41ae8a870 Mon Sep 17 00:00:00 2001
From: Irmen de Jong <irmen@razorvine.net>
Date: Sun, 4 Feb 2024 11:35:09 +0100
Subject: [PATCH] cx16: added cx16.get_program_args() and
 cx16.set_program_args()

---
 compiler/res/prog8lib/cx16/syslib.p8 | 41 ++++++++++++++++++++++++++++
 docs/source/libraries.rst            | 13 +++++++--
 2 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/compiler/res/prog8lib/cx16/syslib.p8 b/compiler/res/prog8lib/cx16/syslib.p8
index bc8971235..2d7d2f3f4 100644
--- a/compiler/res/prog8lib/cx16/syslib.p8
+++ b/compiler/res/prog8lib/cx16/syslib.p8
@@ -1172,6 +1172,47 @@ sub search_x16edit() -> ubyte {
         }}
     }
 
+    sub set_program_args(uword args_ptr, ubyte args_size) {
+        ; Set the inter-program arguments.
+        ; standardized way to pass arguments between programs is in ram bank 0, address $bf00-$bfff.
+        ; see https://github.com/X16Community/x16-docs/blob/master/X16%20Reference%20-%2007%20-%20Memory%20Map.md#bank-0
+        sys.push(getrambank())
+        rambank(0)
+        sys.memcopy(args_ptr, $bf00, args_size)
+        if args_size<255
+            @($bf00+args_size) = 0
+        rambank(sys.pop())
+    }
+
+    asmsub get_program_args(uword buffer @R0, ubyte buf_size @R1, bool binary @Pc) {
+        ; Retrieve the inter-program arguments. If binary=false, it treats them as a string (stops copying at first zero).
+        ; standardized way to pass arguments between programs is in ram bank 0, address $bf00-$bfff.
+        ; see https://github.com/X16Community/x16-docs/blob/master/X16%20Reference%20-%2007%20-%20Memory%20Map.md#bank-0
+        %asm {{
+            lda  #0
+            rol  a
+            sta  P8ZP_SCRATCH_REG
+            lda  $00
+            pha
+            stz  $00
+            stz  P8ZP_SCRATCH_W1
+            lda  #$bf
+            sta  P8ZP_SCRATCH_W1+1
+            ldy  #0
+-           lda  (P8ZP_SCRATCH_W1),y
+            sta  (cx16.r0),y
+            beq  +
+_continue   iny
+            cpy  cx16.r1L           ; max size?
+            bne  -
+            beq  ++
++           lda  P8ZP_SCRATCH_REG   ; binary?
+            bne  _continue
++           pla
+            sta  $00
+        }}
+    }
+
 }
 
 sys {
diff --git a/docs/source/libraries.rst b/docs/source/libraries.rst
index af249bb18..31730b885 100644
--- a/docs/source/libraries.rst
+++ b/docs/source/libraries.rst
@@ -106,7 +106,6 @@ sys (part of syslib)
     including the uninitialized ones ("BSS" variables) and the uninitialized memory blocks reserved by the `memory()` function.
     Can be used to load dynamic data after the program, instead of hardcoding something.
 
-
 ``wait (uword jiffies)``
     wait approximately the given number of jiffies (1/60th seconds)
     Note: the regular system irq handler has run for this to work as it depends on the system jiffy clock.
@@ -527,9 +526,13 @@ The compiler needs it for various built-in system routines.
 cx16
 ----
 This is available on *all targets*, it is always imported as part of syslib.
-On the Commander X16 this module contains a whole bunch of things specific to that machine.
+On the Commander X16 this module contains a *whole bunch* of things specific to that machine.
+It's way too much to include here, you have to study the
+`source code <https://github.com/irmen/prog8/tree/master/compiler/res/prog8lib/cx16/syslib.p8>`_
+to see what is there.
+
 On the other targets, it only contains the definition of the 16 memory mapped virtual registers
-(cx16.r0 - cx16.r15) and the following two utility routines:
+(cx16.r0 - cx16.r15) and the following utility routines:
 
 ``save_virtual_registers()``
     save the values of all 16 virtual registers r0 - r15 in a buffer. Might be useful in an IRQ handler to avoid clobbering them.
@@ -537,6 +540,10 @@ On the other targets, it only contains the definition of the 16 memory mapped vi
 ``restore_virtual_registers()``
     restore the values of all 16 virtual registers r0 - r15 from the buffer. Might be useful in an IRQ handler to avoid clobbering them.
 
+``cpu_is_65816()``
+    Returns true if the CPU in the computer is a 65816, false otherwise (6502 cpu).
+
+
 bmx  (cx16 only)
 ----------------
 Routines to load and save "BMX" files, the CommanderX16 bitmap file format.