1 files changed, 304 insertions, 0 deletions
diff --git a/usr/libc.s b/usr/libc.s
new file mode 100644
index 0000000..5b176d9
--- /dev/null
+++ b/usr/libc.s
@@ -0,0 +1,304 @@
+	.module libc
+	.globl _writes, _putc, _puts, _nl, _strlen, _readc, _sexit, _getpid, _getargs
+	.globl _open, _close, _fgetc, _fputc, _flist, _fremove, _pipe, _ssend, _srecv, _srecv_nb, _pollin, _pollcon
+	.globl _sys_net, _gsleep
+	;; 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$:	ld	a, c
+	ret
+
+	;; char readc(void) -> A   (4 = EOF)
+_readc:
+	ld	c, #2			; SYS_READ
+	rst	#0x30
+	ret
+
+	;; void sexit(unsigned char code /*A*/) - never returns
+_sexit:
+	ld	b, a
+	ld	c, #0			; SYS_EXIT
+	rst	#0x30
+	ret
+
+	;; unsigned char getpid(void) -> A
+_getpid:
+	ld	c, #8			; SYS_GETPID
+	rst	#0x30
+	ret
+
+	;; unsigned char pipe(void) -> A (read fd; write end is read+1)
+_pipe:
+	ld	c, #28			; SYS_PIPE
+	rst	#0x30
+	ret
+
+	;; void ssend(unsigned char b /*A*/)  -- link-port transmit
+_ssend:
+	ld	e, a
+	ld	c, #29			; SYS_SSEND
+	rst	#0x30
+	ret
+
+	;; unsigned char srecv(void) -> A  -- link-port receive (blocks)
+_srecv:
+	ld	c, #30			; SYS_SRECV
+	rst	#0x30
+	ret
+
+	;; int srecv_nb(void) -> byte, or -1 if none (non-blocking)
+_srecv_nb:
+	ld	c, #31			; SYS_SRECVNB
+	rst	#0x30
+	jr	c, 1$
+	ld	c, a
+	ld	b, #0
+	ret
+1$:	ld	bc, #0xffff
+	ret
+
+	;; unsigned char sys_net(void *req /*DE*/) -> A  -- socket layer trap
+_sys_net:
+	ld	c, #33			; SYS_NET (DE already = &netreq)
+	rst	#0x30
+	ret
+
+	;; void gsleep(unsigned char units /*A*/) - delay units*(1/64)s
+_gsleep:
+	ld	b, a
+	ld	c, #34			; SYS_SLEEP
+	rst	#0x30
+	ret
+
+	;; unsigned char pollin(void) -> A  (typed OSK char, or 0)
+_pollin:
+	ld	c, #32			; SYS_POLLIN
+	rst	#0x30
+	ret
+
+	;; unsigned char pollcon(void) -> A  (queued console byte, or 0)
+_pollcon:
+	ld	c, #35			; SYS_POLLCON
+	rst	#0x30
+	ret
+
+	;; unsigned char open(const char *name /*DE*/, unsigned char mode /*A*/) -> A(fd)
+_open:
+	ld	b, a			; B = mode
+	ld	c, #4			; SYS_OPEN
+	rst	#0x30
+	ret
+
+	;; void close(unsigned char fd /*A*/)
+_close:
+	ld	b, a
+	ld	c, #5			; SYS_CLOSE
+	rst	#0x30
+	ret
+
+	;; int fgetc(unsigned char fd /*A*/) -> BC (byte, or -1 at EOF)
+_fgetc:
+	ld	b, a
+	ld	c, #12			; SYS_GETB
+	rst	#0x30
+	jr	c, 1$
+	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
+
+	.globl _yield, _reap
+	;; void yield(void)
+_yield:
+	ld	c, #11			; SYS_YIELD
+	rst	#0x30
+	ret
+	;; unsigned char reap(void) -> A (reaped pid, or 0)
+_reap:
+	ld	c, #22			; SYS_REAP
+	rst	#0x30
+	ret
+
+	.globl _bfill, _bpeek, _bpeek2
+	;; void bfill(unsigned char block /*A*/, unsigned char byte /*E*/)
+_bfill:
+	ld	b, a
+	ld	c, #23			; SYS_BFILL
+	rst	#0x30
+	ret
+	;; unsigned char bpeek(unsigned char block /*A*/) -> A
+_bpeek:
+	ld	b, a
+	ld	e, #0
+	ld	c, #24			; SYS_BPEEK
+	rst	#0x30
+	ret
+	;; unsigned char bpeek2(unsigned char block /*A*/, unsigned char off /*E*/) -> A
+_bpeek2:
+	ld	b, a
+	ld	c, #24			; SYS_BPEEK (off already in E)
+	rst	#0x30
+	ret
+
+
+	.globl _mkdir, _chdir
+	;; unsigned char mkdir(const char *path /*DE*/) -> A (0 ok / $FF)
+_mkdir:
+	ld	c, #25			; SYS_MKDIR
+	rst	#0x30
+	ret
+	;; unsigned char chdir(const char *path /*DE*/) -> A (0 ok / $FF)
+_chdir:
+	ld	c, #26			; SYS_CHDIR
+	rst	#0x30
+	ret
+
+	.globl _opendir
+	;; unsigned char opendir(const char *path /*DE*/) -> A (0 ok / $FF)
+_opendir:
+	ld	c, #27			; SYS_OPENDIR
+	rst	#0x30
+	ret
+
+	.globl _poweroff
+	;; void poweroff(void) - execute the emulator's clean-exit opcode ($ED)
+_poweroff:
+	.db	0xED
+1$:	jr	1$