cc65/libsrc/lynx/read.s

45 lines
1.0 KiB
ArmAsm

;
; Karri Kaksonen, 2010
;
; This function reads count bytes from the place where the address counter is.
; Use lseek to place the address counter where you want to read from.
;
; The file descriptor is ignored in this implementation. The read operation
; reads bytes from a raw cart and does not understand the concept of files.
; So if you read over the end of file you get data from the next file.
;
; The count-parameter is positive (Atari style).
;
; int __fastcall__ read(int fd,void *buf,int count)
;
.importzp _FileDestPtr
.import lynxread0
.import pushax,ldaxysp,ldax0sp,incsp6
.export _read
.segment "CODE"
.proc _read: near
.segment "CODE"
jsr pushax
ldy #$03
jsr ldaxysp
sta _FileDestPtr
stx _FileDestPtr+1
jsr ldax0sp
pha
txa
eor #$FF
tay
pla
eor #$FF
tax
jsr lynxread0
jsr ldax0sp
jmp incsp6
.endproc