From ba2d7ae1d7b319645b10aaa31a7f664f9f80c25c Mon Sep 17 00:00:00 2001 From: user Date: Sat, 18 Jul 2026 00:38:38 +0200 Subject: refactor: c/ -> usr/, compiled program blobs out of the source tree Userland sources live in usr/ (fits the Unix theme better than 'c'). SDCC output .bin blobs land in build/usr/ with the other build artifacts instead of littering the source dir; programs.asm INCBINs them from there. Byte-identical ROM. --- usr/libc.s | 304 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 304 insertions(+) create mode 100644 usr/libc.s (limited to 'usr/libc.s') 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$: jr 1$ -- cgit v1.3.1-sl0p