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fox32rom: Add some convenience routines for copying memory

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ry755 2022-02-11 19:39:33 -08:00 committed by Ry
parent eb46348730
commit e21aae6d08
2 changed files with 52 additions and 0 deletions
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1
main.asm
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@ -165,6 +165,7 @@ mount_boot_disk:
#include "boot.asm"
#include "background.asm"
#include "overlay.asm"
#include "memory.asm"
#include "menu.asm"
#include "submenu.asm"
#include "event.asm"

51
memory.asm Normal file
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@ -0,0 +1,51 @@
; memory copy routines
; copy specified number of bytes from source pointer to destination pointer
; if the source and destination overlap, the behavior is undefined
; inputs:
; r0: pointer to source
; r1: pointer to destinaton
; r2: number of bytes to copy
; outputs:
; none
copy_memory_bytes:
push r0
push r1
push r31
mov r31, r2
copy_memory_bytes_loop:
mov.8 [r1], [r0]
inc r0
inc r1
loop copy_memory_bytes_loop
pop r31
pop r1
pop r0
ret
; copy specified number of words from source pointer to destination pointer
; if the source and destination overlap, the behavior is undefined
; inputs:
; r0: pointer to source
; r1: pointer to destinaton
; r2: number of words to copy
; outputs:
; none
copy_memory_words:
push r0
push r1
push r31
mov r31, r2
copy_memory_words_loop:
mov [r1], [r0]
add r0, 4
add r1, 4
loop copy_memory_words_loop
pop r31
pop r1
pop r0
ret