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* docs: drop the link-drop investigation writeupuser3 days1-2/+0
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* hooks: clang-format pre-commit (changed lines only) + .clang-formatuser3 days1-0/+1
| | | | | | | | | Same setup as sl0pboy: git-clang-format scopes formatting to the lines each commit touches, re-adds the formatted files, and refuses partially-staged C files. Style file matches the house style (4-space, attached braces, 100 cols, short cases/ifs inline, no include sorting - order is load-bearing for SDCC userland). Enable once: git config core.hooksPath hooks
* docs: concise README (networking + demo gif up front); internals.mduser3 days1-344/+69
| | | | | | | | | README is now pitch -> proof (real capture gif) -> quick start -> docs pointers, with the network stack and gbhub/gbjoin/gbtype getting explicit billing. The full technical breakdown (memory model, syscall ABI, fork/exec/context switch, FS layout, toolchain war stories) moves to docs/internals.md, plus previously-undocumented sections on the network stack and the terminal/OSK.
* refactor: c/ -> usr/, compiled program blobs out of the source treeuser4 days1-10/+10
| | | | | | | 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.
* fs rewrite stage 3: nested directories, paths, cwd (cd/mkdir/ls)user6 days1-6/+17
| | | | | | | | | | | | | | | | - directories generalized: dir_find/dir_add/dir_remove take any dir inode; every dir carries '.'/'..'. Path resolution (resolve / resolve_parent) walks absolute or cwd-relative paths; open/mkdir/chdir/remove/opendir take paths. - per-process cwd: PROC_CWD in the PCB (root by default, inherited on fork); sys_chdir sets it, sys_opendir points ls at any directory. - shell: 'cd' builtin + cwd-aware prompt; 'mkdir'/'ls <dir>' tools; 'exit'/'quit' and EOF call poweroff() (clean shutdown via the $ED opcode -> reliable save). - three HL/buffer-clobber bugs fixed along the way: resolve didn't preserve the path cursor across dir_find; cur_cwd clobbered HL; resolve_parent set the final name before resolve() overwrote wFsNameBuf (now copied after). - verified: nested mkdir/cd/save, multi-level paths (cat docs/sub/b), and the whole tree persists across a reboot. - README: document directories + the poweroff opcode.
* fs rewrite stage 2: inodes + root directory (block-based, persistent)user6 days1-30/+26
| | | | | | | | | | | | | | | | - fs.asm: a real block filesystem on the persistent block device - superblock, block/inode bitmaps, a 32-entry inode table (type, size, 8 direct block pointers -> files up to 2 KiB), and a root directory of 16-byte entries. Metadata cached in WRAMX; one-block data cache streams file/dir blocks. - same syscall interface (open/getb/putb/list/remove) -> tools unchanged; ls now enumerates until flist() runs out (16 files, was hardcoded 8). - old 8-slot WRAM FS removed; cart RAM partitioned: process banks 0-7, disk 8-11. - two register-clobber bugs fixed: alloc_block/alloc_inode returned the bitmap-block number (write_bitmap clobbers C); db_use loaded the wrong block on a transition (db_flush->write_block clobbers C) -> multi-block files broke. - verified: 10+ files, multi-block (300-byte) files, delete, and persistence across reboots. Debug 'blk' disk tool retained (fill/peek). - README: document the block filesystem.
* fs rewrite stage 1: persistent block device (bounce buffer, cart SRAM)user6 days1-1/+14
| | | | | | | | | | | | | | - blk.asm: read_block/write_block move 256-byte blocks between battery-backed cart-RAM banks (8-11, the 'disk') and a WRAM bounce buffer. Banking is hidden in those two routines; they inline the 'restore my bank' step so they never touch the stack while the disk bank is mapped over the process's $A000 window (the stack lives there too -- a call/ret would rug-pull it). - format-on-first-boot: superblock magic in block 0; otherwise the disk persists. - cart RAM bumped to 128 KiB (-r 4); process banks 0-7, disk banks 8-11. - debug tool 'blk fill/peek' + syscalls to validate round-trip and persistence. - verified: round-trip incl. cross-bank (block 100 -> bank 11); block survives a reboot via .sav; magic intact (no reformat on 2nd boot). - old WRAM 8-slot FS still backs the tools until stages 2-3.
* jobs: background execution (&), non-blocking reap, spin demouser6 days1-0/+29
| | | | | | | | | | | - sys_reap: nohang reap of a finished zombie child (-> pid or 0). - shell: 'cmd &' launches in the background (prints [pid], no wait); reaps finished jobs at the prompt ([pid done]). Foreground now waits for its own child specifically (loops wait(), reporting bg completions meanwhile) so kill reports the right pid. - spin: a process that yields forever - a target for ps/kill. - verified: spin &; ps shows it; kill <pid> removes just that one; immortal init; self-finishing bg worker reaped with [pid done].
* shell: I/O redirection (>/<) and pipes (|); rewrite shell in Cuser6 days1-12/+25
| | | | | | | | | | | | | - kernel I/O routing: PCB gains PROC_STDIN/PROC_STDOUT (default console $FF), inherited across fork. KGetc/KPutc route read/write/putc to the console or a file fd. New syscalls: putc(16), setin(17), setout(18), lookup(19). read/write now go through the routing; putc/puts/nl use SYS_PUTC. - sys_lookup + NameTable move command-name resolution into the kernel. - shell rewritten in C (c/sh.c): tokenizes a line, parses > / < / |, and drives fork+setin/setout+exec+wait. Pipes run as 'a > __pipe ; b < __pipe' (temp file). asm shell + cmdtab removed; StrEqual/SkipName kept for sys_lookup. - libc: fork/exec/wait/setin/setout/lookup wrappers. - verified: echo>file, cat file, wc<file, cat readme|wc -l, echo ...|wc.
* filesystem: a RAM FS (WRAMX) + ls/cat/save/rm; wc/head read filesuser6 days1-4/+41
| | | | | | | | | | | - fs.asm: 8-slot RAM filesystem in WRAMX ($D000-$DFFF), name[8]+len[2]+data[502]; syscalls open/close/getb/putb/list/remove, seeded with a 'readme' at boot. - libc: open/close/fgetc/fputc/flist/fremove wrappers + O_READ/O_WRITE/NOFD. - tools: ls, save (stdin->file, one line), rm; cat/wc/head now take a file arg. - fix: syscall dispatch clobbers A, so putb takes its byte in E (was reading the handler's low address byte, 0xDC); ls NUL-terminates 8-char names. - verified: save/cat/ls/rm cycle; wc readme -> '2 7 38'; head -n 1 readme. - README: document the filesystem + the A-clobber ABI note.
* tools: wc, head, and an argc/argv demo (args) + libc.c helpersuser6 days1-12/+27
| | | | | | | | | | - c/libc.c: shared C helpers linked into every program - putu (print decimal), atou (parse decimal), argv_parse (tokenize getargs() into argc/argv). - wc: count lines/words/chars of stdin. head [n]: first n lines (drains rest to EOF). args: argc/argv demo. - pid now uses libc putu; build.sh links libc.c; Makefile CBLOBS + libc dep. - README: document the new tools + argv_parse. - verified: 'args one two three' -> argc=3/argv[..]; wc '2 3 16'; head 2.
* libc + CLI tools: a small C userlanduser6 days1-5/+35
| | | | | | | | | | | - libc: add putc, puts, strlen, getargs (args string), EOF (=4) for readc. - args: shell splits the command line at the first space ("cmd\0args\0" at $A000, inherited by the child via fork); getargs() returns the arg string. - shell: exit on Ctrl-D/EOF; $ prompt over a clean read loop. - tools (c/): echo (argv), cat (stdin->stdout to EOF), uname, pid (decimal print), true, false. Each built to a ROM-bank blob and registered. - Makefile: CBLOBS list builds all C programs. - README: document libc + the tool set.
* C toolchain: run SDCC-compiled C programs as gbos processesuser6 days1-1/+40
| | | | | | | | | | | | | - c/{gbos.h,crt0.s,libc.s,build.sh}: SDCC sm83 -> ROM-bank blob toolchain. libc syscall wrappers save/restore BC/DE/HL around rst $30 (trap clobbers them; SDCC expects them preserved). - build via SDCC native asxxxx path (sdasgb/sdldgb), crt0 linked first so _start is the $4000 entry; blob INCBIN'd into a ROM bank. - chello.c: prints a message + getpid() -> runs as 'chello' shell command. - Makefile: auto-build c/*.bin, track as a dep of programs.o; gitignore blobs. - README: document the C toolchain + the SDCC --asm=rgbds codegen bug that forced the native-toolchain approach. - verified: '$ chello' -> 'hello from C on gbos!' / 'my pid is 2'.
* shell working: fix syscall ABI (trap clobbers HL) + documentuser6 days1-2/+22
| | | | | | | | | | | - root cause of the read/echo corruption: SyscallTrap uses HL to index the dispatch table, so HL is clobbered across a syscall; the shell then wrote its buffer pointer's garbage into the $0000-$7FFF MBC register region, corrupting the mapper. fix: userland saves HL around sys_read (push/pop). - shell now runs commands end to end: $ hello -> hello world!, $ worker -> worker!, $ foo -> ? - README: document that syscalls clobber BC/DE/HL (return in A, B for wait); add read + shell to the syscall table.
* kernel: complete the process lifecycle (exit/wait/reap + bank free list)user6 days1-2/+26
| | | | | | | | | | | | | | - exit(): zombie + status, reparent orphans to init, wake blocked parent, schedule away forever (resources reclaimed by the reaper) - wait(): scan for a zombie child; reap (free cart-RAM bank + PCB slot) and return pid/code; block PS_BLOCKED + yield if children still live; $FF if none - cart-RAM banks are now a free list (wBankUsed bitmap): AllocRamBank/FreeRamBank - scheduler: FindNextReady returns carry when nothing runnable; yield idles instead of blindly picking slot 0 - helpers: FindPcbByPid, ReparentToInit - demo: init forks 3 workers -> exec -> exit(pid) -> wait/reap => wwwR2R3R4! verified bank recycling with 6 workers over 3 banks (w2w3w4w5w6w7) - README: document the lifecycle + syscall status
* kernel: implement exec()user6 days1-2/+21
| | | | | | | | | | - sys_exec(B=program id): look up ProgramTable, point PROC_ROMB at the program's ROM text bank, map it into $4000-$7FFF, reset stack, jp to entry (no return) - programs.asm: two demo programs (ping/pong) ORG'd at the SAME $4000 in banks 2 and 3 - proves execution is driven purely by PROC_ROMB - demo: init forks; parent execs PROG_PING (bank2, '1'), child execs PROG_PONG (bank3, '2') -> '1212...', 2000/2000 balanced, zero garbage - README: document exec + text-in-ROM model
* kernel: implement fork()user6 days1-2/+22
| | | | | | | | | | - sys_fork: switch to a kernel stack, bump-allocate a cart-RAM bank, copy the parent's 8 KiB bank via a WRAM bounce buffer, plant a switch-in frame so the child returns 0 to the post-fork PC, fill the child PCB (shared ROM text) - add AllocRamBank (bump allocator) + FindFreeSlot helpers - demo: init forks; parent prints P, child prints C (PCPC...); nested fork gives three distinct pids (123...) - README: document the fork mechanism, mark syscall status
* gbos scaffold: working cooperative microkernel (verified ABAB in emulator)user6 days1-0/+102
- fix ClearKernelRAM clobbering the kernel stack (only clear $C000-$CBFF) - fix SyscallTrap clobbering DE (buffer arg) during table dispatch - README: run via ~/dev/gbc --headless; note bring-up bugs