gbos.git/src/fs.asm, branch master

kernel: dmesg-style boot spew before init spawns

2026-07-17T22:46:26Z

Print everything the kernel knows implicitly at boot, Linux-flavored, on the LCD console and mirrored over the link (gbhub logs each GB's boot): gbos sm83 microkernel console: CGB (boot a=$11) <- boot ROM's A/B, saved at entry cart: mbc5, 1M rom, 128K sram <- our own cart header ($0147-49) mem: 32K wram 16K vram 127B hram <- CGB constants proc: 8 slots, 31 programs <- link-time table sizes net: slip on link port, 4 sockets fs: gbfs v3 mounted, 120/128 blk free <- bitmap popcount; 'formatted' tty: 40x18 console, SELECT = osk on first boot init: spawning pid 1 New src/dmesg.asm with kernel print helpers (kputc/kputs/kputhex/kputdec) that bypass KPutc (no process context at boot). term_init now runs before net/fs init so the spew is visible as subsystems come up.

kernel+sh: real anonymous pipes (concurrent, streaming, SIGPIPE)

2026-07-16T23:04:16Z

Replace the shell's temp-file pipe hack with proper in-kernel FIFOs. Kernel (src/pipe.asm, new): - A small pool of bounded ring buffers (PIPE_MAX=2, 64 B each) with writers/readers refcounts. Pipe fds are $F0+idx*2 (read) / +1 (write); $FF stays "console". - SYS_PIPE allocates one (writers=readers=1) and returns the read fd (write = read+1). getb/putb/close dispatch pipe fds here; sys_exit drops the refcounts held as PROC_STDIN/PROC_STDOUT. - Blocking with SchedYield, which is the flow control: read blocks while empty with a writer (EOF once writers hit 0), write blocks while full with a reader, and if the last reader is gone the writer is killed (SIGPIPE -> exit 141). Cooperative-scheduler friendly. Shell (c/sh.c): - run_pipeline(): split on '|', make a pipe between adjacent stages, and fork ALL stages concurrently (no wait between), wiring stdin/stdout; then wait for all. Per-stage >/< still honored; orphaned pipe ends are closed on a lookup miss so EOF/EPIPE propagate. - Drop the __pipe temp file and its 2 KB / serialized limits. libc: pipe(). New c/ptest.c exercises the FIFO (write, read back, EOF). Now works (old version couldn't): multi-stage a|b|c; streaming beyond 2 KB (count 120 | wc = 3372 bytes through a 64 B buffer); early-exit SIGPIPE (count 200 | true kills count instead of hanging/overflowing a file).

fs: reject open()/read() on a directory (EISDIR)

2026-07-16T11:07:28Z

open() now checks the target's inode type: opening a directory as a file returns $FE (EISDIR) instead of a valid fd, so 'cat docs' no longer streams the raw directory block as bytes. cat reports 'is a directory'; wc/head/save treat any invalid fd (>3) as an open failure. (ls is unaffected - it uses the structural opendir/list path, not open/getb.)

fs rewrite stage 3: nested directories, paths, cwd (cd/mkdir/ls)

2026-07-16T10:49:19Z

- 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 ' 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)

2026-07-16T10:20:57Z

- 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.

filesystem: a RAM FS (WRAMX) + ls/cat/save/rm; wc/head read files

2026-07-16T05:53:19Z

- 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.