From 69fbcb30fd393277c93eade43737a52d20582c47 Mon Sep 17 00:00:00 2001
From: Oliver Schmidt <ol.sc@web.de>
Date: Mon, 7 Mar 2016 01:44:19 +0100
Subject: [PATCH] Use AX paradigm for stack initalization.

---
 libsrc/atari5200/crt0.s |  4 ++--
 libsrc/gamate/crt0.s    |  4 ++--
 libsrc/nes/crt0.s       |  4 ++--
 libsrc/pce/crt0.s       | 17 ++++++++---------
 4 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/libsrc/atari5200/crt0.s b/libsrc/atari5200/crt0.s
index 7073bb2a7..ee3d0de4f 100644
--- a/libsrc/atari5200/crt0.s
+++ b/libsrc/atari5200/crt0.s
@@ -27,9 +27,9 @@ start:
 ; Set up the stack.
 
         lda     #<(__RAM_START__ + __RAM_SIZE__ - __RESERVED_MEMORY__)
+        ldx     #>(__RAM_START__ + __RAM_SIZE__ - __RESERVED_MEMORY__)
         sta     sp
-        lda     #>(__RAM_START__ + __RAM_SIZE__ - __RESERVED_MEMORY__)
-        sta     sp+1            ; Set argument stack ptr
+        stx     sp+1            ; Set argument stack ptr
 
 ; Call the module constructors.
 
diff --git a/libsrc/gamate/crt0.s b/libsrc/gamate/crt0.s
index 99af9b2d9..5a5bb3aa0 100644
--- a/libsrc/gamate/crt0.s
+++ b/libsrc/gamate/crt0.s
@@ -20,7 +20,7 @@ Start:
         ldx     #0
         stx     ZP_IRQ_CTRL     ; disable calling cartridge IRQ/NMI handler
 
-        ; Setup stack and memory mapping
+        ; Set up stack and memory mapping
         ;ldx     #$FF            ; Stack top ($01FF)
         dex
         txs
@@ -31,7 +31,7 @@ Start:
         ; Copy the .data segment to RAM
         jsr     copydata
 
-        ; setup the stack
+        ; Set up the stack
         lda     #<(__RAM_START__+__RAM_SIZE__)
         ldx     #>(__RAM_START__+__RAM_SIZE__)
         sta     sp
diff --git a/libsrc/nes/crt0.s b/libsrc/nes/crt0.s
index de874d363..4d258ff9e 100644
--- a/libsrc/nes/crt0.s
+++ b/libsrc/nes/crt0.s
@@ -100,9 +100,9 @@ start:
 ; Set up the stack.
 
         lda     #<(__SRAM_START__ + __SRAM_SIZE__)
+        ldx     #>(__SRAM_START__ + __SRAM_SIZE__)
         sta     sp
-        lda     #>(__SRAM_START__ + __SRAM_SIZE__)
-        sta     sp+1            ; Set argument stack ptr
+        stx     sp+1            ; Set argument stack ptr
 
 ; Call the module constructors.
 
diff --git a/libsrc/pce/crt0.s b/libsrc/pce/crt0.s
index e92e9eca3..80b32c089 100644
--- a/libsrc/pce/crt0.s
+++ b/libsrc/pce/crt0.s
@@ -39,22 +39,21 @@
 
 start:
 
-        ; setup the CPU and System-IRQ
+        ; Set up the CPU and System-IRQ
 
         ; Initialize CPU
-
         sei
         nop
-        csh                     ; set high speed CPU mode
+        csh                     ; Set high speed CPU mode
         nop
         cld
         nop
 
-        ; Setup stack and memory mapping
+        ; Set up stack and memory mapping
         ldx     #$FF            ; Stack top ($21FF)
         txs
 
-        ; at startup all MPRs are set to 0, so init them
+        ; At startup all MPRs are set to 0, so init them
         lda     #$ff
         tam     #%00000001      ; 0000-1FFF = Hardware page
         lda     #$F8
@@ -98,11 +97,11 @@ start:
         ; Copy the .data segment to RAM
         tii     __DATA_LOAD__, __DATA_RUN__, __DATA_SIZE__
 
-        ; setup the stack
+        ; Set up the stack
         lda     #<(__RAM_START__+__RAM_SIZE__)
+        ldx     #>(__RAM_START__+__RAM_SIZE__)
         sta     sp
-        lda     #>(__RAM_START__+__RAM_SIZE__)
-        sta     sp + 1
+        stx     sp + 1
 
         ; Call module constructors
         jsr     initlib
@@ -114,7 +113,7 @@ start:
         jsr     push0           ; argv
 
         ldy     #4              ; Argument size
-        jsr     _main           ; call the users code
+        jsr     _main           ; Call the users code
 
         ; Call module destructors. This is also the _exit entry.
 _exit:
-- 
2.39.5