mirror of
https://github.com/cc65/cc65.git
synced 2024-11-04 17:04:58 +00:00
70 lines
1.4 KiB
ArmAsm
70 lines
1.4 KiB
ArmAsm
;
|
|
; int snprintf (char* buf, size_t size, const char* Format, ...);
|
|
;
|
|
; Ullrich von Bassewitz, 2009-09-26
|
|
;
|
|
|
|
.export _snprintf
|
|
.import pushax, addysp, decsp6, _vsnprintf
|
|
.importzp sp, ptr1
|
|
|
|
.macpack generic
|
|
|
|
; ----------------------------------------------------------------------------
|
|
; Data
|
|
|
|
.bss
|
|
|
|
ParamSize: .res 1 ; Number of parameter bytes
|
|
|
|
; ----------------------------------------------------------------------------
|
|
; Code
|
|
|
|
.code
|
|
|
|
|
|
_snprintf:
|
|
sty ParamSize ; Number of param bytes passed in Y
|
|
|
|
; We have to push buf/size/format, both in the order they already have on stack.
|
|
; To make this somewhat more efficient, we will create space on the stack and
|
|
; then do a copy of the complete block instead of pushing each parameter
|
|
; separately. Since the size of the arguments passed is the same as the size
|
|
; of the fixed arguments, this will allow us to calculate the pointer to the
|
|
; fixed size arguments easier (they're just ParamSize bytes away).
|
|
|
|
jsr decsp6
|
|
|
|
; Calculate a pointer to the Format argument
|
|
|
|
lda ParamSize
|
|
add sp
|
|
sta ptr1
|
|
ldx sp+1
|
|
bcc @L1
|
|
inx
|
|
@L1: stx ptr1+1
|
|
|
|
; Now copy buf/size/format
|
|
|
|
ldy #6-1
|
|
@L2: lda (ptr1),y
|
|
sta (sp),y
|
|
dey
|
|
bpl @L2
|
|
|
|
; Load va_list (last and __fastcall__ parameter to vsprintf)
|
|
|
|
lda ptr1
|
|
ldx ptr1+1
|
|
|
|
; Call vsnprintf
|
|
|
|
jsr _vsnprintf
|
|
|
|
; Cleanup the stack. We will return what we got from vsprintf
|
|
|
|
ldy ParamSize
|
|
jmp addysp
|
|
|