fix variable init order mistake in program startup

reset multiply bit at end of verafx.muls

codeGenCpu6502/src/prog8/codegen/cpu6502/ProgramAndVarsGen.kt

@@ -470,6 +470,9 @@ internal class ProgramAndVarsGen(
     }
 
     private fun entrypointInitialization() {
+        // zero out the BSS area first, before setting the variable init values
+        asmgen.out("  jsr  prog8_lib.program_startup_clear_bss")
+
         // initialize block-level (global) variables at program start
         blockVariableInitializers.forEach {
             if (it.value.isNotEmpty())
@@ -521,8 +524,7 @@ internal class ProgramAndVarsGen(
             arrayVariable2asm(varname, it.alloc.dt, it.value, null)
         }
 
-        // zero out the BSS area
-        asmgen.out("+    jsr  prog8_lib.program_startup_clear_bss")
+        asmgen.out("+")
     }
 
     private class ZpStringWithInitial(

compiler/res/prog8lib/atari/syslib.p8

@@ -29,10 +29,7 @@ sys {
         ; TODO
         %asm {{
             sei
-            cld
-            clc
             ; TODO reset screen mode etc etc
-            clv
             cli
             rts
         }}
@@ -40,7 +37,10 @@ sys {
 
     asmsub  init_system_phase2()  {
         %asm {{
-            rts     ; no phase 2 steps on the Atari
+            cld
+            clc
+            clv
+            rts
         }}
     }
 

compiler/res/prog8lib/c128/syslib.p8

@@ -360,7 +360,6 @@ asmsub  init_system()  {
     ; Uppercase charset is activated.
     %asm {{
         sei
-        cld
         lda  #0
         sta  $ff00      ; select default bank 15
         jsr  cbm.IOINIT
@@ -373,8 +372,6 @@ asmsub  init_system()  {
         lda  #0
         sta  c64.BGCOL0
         jsr  disable_runstop_and_charsetswitch
-        clc
-        clv
         cli
         rts
     }}
@@ -382,7 +379,10 @@ asmsub  init_system()  {
 
 asmsub  init_system_phase2()  {
     %asm {{
-        rts     ; no phase 2 steps on the C128
+        cld
+        clc
+        clv
+        rts
     }}
 }
 

compiler/res/prog8lib/c64/syslib.p8

@@ -357,7 +357,6 @@ asmsub  init_system()  {
     ; Uppercase charset is activated.
     %asm {{
         sei
-        cld
         lda  #%00101111
         sta  $00
         lda  #%00100111
@@ -372,8 +371,6 @@ asmsub  init_system()  {
         lda  #0
         sta  c64.BGCOL0
         jsr  disable_runstop_and_charsetswitch
-        clc
-        clv
         cli
         rts
     }}
@@ -381,7 +378,10 @@ asmsub  init_system()  {
 
 asmsub  init_system_phase2()  {
     %asm {{
-        rts     ; no phase 2 steps on the C64
+        cld
+        clc
+        clv
+        rts
     }}
 }
 

compiler/res/prog8lib/cx16/syslib.p8

@@ -1370,7 +1370,6 @@ asmsub  init_system()  {
         tax
         tay
         jsr  cx16.mouse_config  ; disable mouse
-        cld
         lda  cx16.VERA_DC_VIDEO
         and  #%00000111 ; retain chroma + output mode
         sta  P8ZP_SCRATCH_REG
@@ -1400,8 +1399,6 @@ asmsub  init_system()  {
         lda  #0
         tax
         tay
-        clc
-        clv
         cli
         rts
     }}
@@ -1417,6 +1414,9 @@ asmsub  init_system_phase2()  {
         lda  #PROG8_VARSHIGH_RAMBANK
         sta  $00    ; select ram bank
         cli
+        cld
+        clc
+        clv
         rts
     }}
 }

compiler/res/prog8lib/cx16/verafx.p8

@@ -179,6 +179,7 @@ verafx {
             ldx  cx16.VERA_DATA0
             stx  cx16.r0s+1
             stz  cx16.VERA_FX_CTRL    ; Cache write disable
+            stz  cx16.VERA_FX_MULT    ; $9F2C  reset multiply bit
             stz  cx16.VERA_CTRL       ; reset DCSEL
             rts
         }}

compiler/res/prog8lib/pet32/syslib.p8

@@ -104,13 +104,10 @@ asmsub  init_system()  {
     ; Uppercase charset is activated.
     %asm {{
         sei
-        cld
         lda  #142
         jsr  cbm.CHROUT     ; uppercase
         lda  #147
         jsr  cbm.CHROUT     ; clear screen
-        clc
-        clv
         cli
         rts
     }}
@@ -118,7 +115,10 @@ asmsub  init_system()  {
 
 asmsub  init_system_phase2()  {
     %asm {{
-        rts     ; no phase 2 steps on the PET
+        cld
+        clc
+        clv
+        rts
     }}
 }
 

compiler/res/prog8lib/prog8_lib.asm

@@ -18,8 +18,6 @@ program_startup_clear_bss    .proc
 		lda  #0
 		jsr  prog8_lib.memset
 	.endif
-		clv
-		clc
 		rts
 		.pend
 

docs/source/todo.rst

@@ -1,6 +1,9 @@
 TODO
 ====
 
+Commit "tweak program start initialization and fix cleanup at exit for atari and pet compiler targets #04cb684f"  causing programs to crash (assem, rockrunner)
+
+
 Improve register load order in subroutine call args assignments:
 in certain situations, the "wrong" order of evaluation of function call arguments is done which results
 in overwriting registers that already got their value, which requires a lot of stack juggling (especially on plain 6502 cpu!)

examples/test.p8

@@ -1,20 +1,14 @@
 %import textio
-%import verafx
 %zeropage basicsafe
 %option no_sysinit
 
 main {
-
-    word @shared w1 = -30
-    word @shared w2 = -40
-    uword @shared uw1 = 9999
-    uword @shared uw2 = 4
-
+    ubyte @shared @nozp value1 = 99
+    ubyte @shared @requirezp value2 = 42
     sub start() {
-        cx16.r0 = 12345
-        txt.print_uw(verafx.mult16(uw1, uw2))
-        txt.spc()
-        txt.print_uw(uw1 * uw2)
+        txt.print_ub(value1)
+        txt.nl()
+        txt.print_ub(value2)
         txt.nl()
     }
 }