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.module libc
.globl _writes, _putc, _puts, _nl, _strlen, _readc, _sexit, _getpid, _getargs
.globl _open, _close, _fgetc, _fputc, _flist, _fremove
;; SDCC sm83 sdcccall(1): 1st arg -> A (byte) or DE (pointer); ret A / BC.
;; rst $30 (the trap) clobbers BC/DE/HL; SDCC treats them caller-saved, so
;; wrappers need not preserve them - but we compute cleanly regardless.
.area _CODE
;; void writes(const char *buf /*DE*/, unsigned char len /*A*/)
_writes:
ld b, a
ld c, #3 ; SYS_WRITE
rst #0x30
ret
;; char *getargs(void) -> BC : the arg string (command line past word 1).
;; The shell leaves "cmd\0args\0" at 0xA000, inherited by the child via fork.
_getargs:
ld hl, #0xa000
1$: ld a, (hl)
inc hl
or a
jr nz, 1$
ld b, h
ld c, l
ret
;; void putc(char c /*A*/) -> stdout via SYS_PUTC
_putc:
ld e, a
ld c, #16 ; SYS_PUTC
rst #0x30
ret
;; void puts(const char *s /*DE*/) - write until NUL (no newline)
_puts:
1$: ld a, (de)
or a
ret z
push de
ld e, a
ld c, #16 ; SYS_PUTC
rst #0x30
pop de
inc de
jr 1$
;; void nl(void) - CRLF via stdout
_nl:
ld e, #0x0d
ld c, #16 ; SYS_PUTC
rst #0x30
ld e, #0x0a
ld c, #16
rst #0x30
ret
;; unsigned char strlen(const char *s /*DE*/) -> A
_strlen:
ld c, #0
1$: ld a, (de)
or a
jr z, 2$
inc c
inc de
jr 1$
2$: ld a, c
ret
;; char readc(void) -> A (4 = EOF)
_readc:
ld c, #2 ; SYS_READ
rst #0x30
ret
;; void sexit(unsigned char code /*A*/) - never returns
_sexit:
ld b, a
ld c, #0 ; SYS_EXIT
rst #0x30
ret
;; unsigned char getpid(void) -> A
_getpid:
ld c, #8 ; SYS_GETPID
rst #0x30
ret
;; unsigned char open(const char *name /*DE*/, unsigned char mode /*A*/) -> A(fd)
_open:
ld b, a ; B = mode
ld c, #4 ; SYS_OPEN
rst #0x30
ret
;; void close(unsigned char fd /*A*/)
_close:
ld b, a
ld c, #5 ; SYS_CLOSE
rst #0x30
ret
;; int fgetc(unsigned char fd /*A*/) -> BC (byte, or -1 at EOF)
_fgetc:
ld b, a
ld c, #12 ; SYS_GETB
rst #0x30
jr c, 1$
ld c, a
ld b, #0
ret
1$: ld bc, #0xffff
ret
;; void fputc(unsigned char fd /*A*/, char ch /*E*/)
;; byte goes to the kernel in E (the trap clobbers A during dispatch)
_fputc:
ld b, a ; B = fd (ch stays in E)
ld c, #13 ; SYS_PUTB
rst #0x30
ret
;; unsigned char flist(unsigned char slot /*A*/, char *namebuf /*DE*/) -> A
_flist:
ld b, a
ld c, #14 ; SYS_LIST
rst #0x30
ret
;; void fremove(const char *name /*DE*/)
_fremove:
ld c, #15 ; SYS_REMOVE
rst #0x30
ret
.globl _fork, _exec, _wait, _setin, _setout, _lookup
;; unsigned char fork(void) -> A (child pid in parent, 0 in child)
_fork:
ld c, #1 ; SYS_FORK
rst #0x30
ret
;; void exec(unsigned char id /*A*/) - never returns
_exec:
ld b, a
ld c, #6 ; SYS_EXEC
rst #0x30
ret
;; unsigned char wait(void) -> A (reaped pid)
_wait:
ld c, #7 ; SYS_WAIT
rst #0x30
ret
;; void setin(unsigned char fd /*A*/)
_setin:
ld b, a
ld c, #17 ; SYS_SETIN
rst #0x30
ret
;; void setout(unsigned char fd /*A*/)
_setout:
ld b, a
ld c, #18 ; SYS_SETOUT
rst #0x30
ret
;; unsigned char lookup(const char *name /*DE*/) -> A (prog id or $FF)
_lookup:
ld c, #19 ; SYS_LOOKUP
rst #0x30
ret
.globl _kill, _psget, _progname
;; unsigned char kill(unsigned char pid /*A*/) -> A (0 ok, $FF fail)
_kill:
ld b, a
ld c, #9 ; SYS_KILL
rst #0x30
ret
;; unsigned char psget(unsigned char slot /*A*/, unsigned char *buf /*DE*/) -> A
_psget:
ld b, a
ld c, #20 ; SYS_PS
rst #0x30
ret
;; void progname(unsigned char id /*A*/, char *buf /*DE*/)
_progname:
ld b, a
ld c, #21 ; SYS_PROGNAME
rst #0x30
ret
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