Files
Sprinter-SDCC/libc/io/env.c
T
snark13 c71e249a4e Add full compiler toolchain, libc, examples and reference docs
First substantive commit: the entire Sprinter C compiler tree on top of
the bare README+gitignore initial commit.

What's in here:
  bin/sprinter-cc        — driver script invoking SDCC + linker + mkexe
  libc/                  — Sprinter-specific libc layer over ESTEX/BIOS
                           (conio, gfx, io, mem, stdio + headers)
  runtime/               — crt0 variants (default/small/banked/minimal)
                           + heap + bank trampolines
  toolchain/             — mkexe (SprintEXE packer, C + tests)
  examples/              — 30 demo programs (gfx, file I/O, env, time, …)
  lib/Makefile           — builds the libc archive (sprinter.lib)
  docs/                  — converted Sprinter manuals + asm reference samples
  third_party/           — solid-c reference compiler dump + sdcc setup script
  release_docs/          — packaging / release notes

gitignore overhaul:
  • Drop dangerous blanket patterns: *.asm (would hide docs/samples/*.asm)
    and *.exe (case-insensitive match was hiding third_party/solid-c/*.EXE
    on macOS APFS).  Replaced with examples/*/*.{asm,exe,…} and lib/*.lib.
  • Restore tracking of toolchain/mkexe/tests/{one,big}.bin — those are
    INPUT fixtures, not build outputs.
  • Collapse the duplicated SDCC/C/Sdcc sections into one section per
    concern (build outputs / vendored / OS-junk).
  • Add .sprinter-cc-*/, build/ (catches lib/build/ too), .claude/.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-06-03 16:13:21 +03:00

94 lines
2.7 KiB
C

/*
* getenv / putenv via ESTEX ENVIRON ($46).
*
* ESTEX $46 subfn 1 (getenv):
* in: HL = name (ASCIIZ), DE = output buffer (caller-owned)
* out: CF=0 + A != 0 → variable found, value written into [DE..end-1]
* CF=0 + A == 0 → variable not present (note: this is the
* opposite of what DiskSyscalls.txt v1.6 docs
* claim — verified empirically and against
* solid-c's IO.ASM:763-766 implementation)
* CF=1 → error, A = code
* DE on exit points at one past the last byte written
*
* ESTEX $46 subfn 2 (putenv):
* in: HL = "NAME=value" (NUL-terminated)
* out: CF=1 / A = error code on failure
*
* We hand back a pointer into a private 128-byte buffer for getenv().
* Caller must copy the bytes before the next getenv() call if they
* need to outlive it.
*/
#include <stdint.h>
#include <sprinter.h>
static char env_buf[128];
char *getenv(const char *name) __naked
{
(void)name;
__asm
push ix
;; HL = name on entry; we need to also load DE = env_buf.
ld de, #_env_buf
ld bc, #0x0146 ; ESTEX ENVIRON; subfn: getenv
rst #0x10
pop ix
jr c, _getenv_err
or a, a
jr Z, _getenv_miss
ld de, #_env_buf
ret
_getenv_err:
call __errno_set
_getenv_miss:
ld de, #0
ret
__endasm;
}
int putenv(const char *namevalue) __naked
{
(void)namevalue;
__asm
push ix
ld bc, #0x0246 ; ESTEX ENVIRON; subfn: setenv
rst #0x10
pop ix
jr c, _putenv_err
ld de, #0
ret
_putenv_err:
call __errno_set
ld de, #-1
ret
__endasm;
}
/* ESTEX $46 subfn 0 (sysenv):
* in: HL = caller-owned buffer
* out: caller's buffer is filled with one NUL-terminated "NAME=value"
* per env var, then a trailing extra NUL marks the end:
* "PATH=...\0SOLID=H\0\0"
* return: buf on success, -1 on error (errno set).
* Buffer must be large enough for the whole environment.
*/
char *sysenv(char *buf) __naked
{
(void)buf;
__asm
push ix
push hl ; stash buffer pointer (= return value)
ld bc, #0x0046 ; ESTEX ENVIRON; subfn 0 = sysenv
rst #0x10
pop de ; DE = buffer pointer
pop ix
ret nc ; success: DE already has buf
;; CF=1 A = ESTEX error code.
call __errno_set
ld de, #-1
ret
__endasm;
}