From 4335d248d18987a050d8ac26965c90718eef7562 Mon Sep 17 00:00:00 2001
From: user <user@clank>
Date: Thu, 16 Jul 2026 07:21:40 +0200
Subject: libc + CLI tools: a small C userland

- 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.
---
 src/programs.asm | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 68 insertions(+), 3 deletions(-)

(limited to 'src')

diff --git a/src/programs.asm b/src/programs.asm
index eabe56f..322c7fc 100644
--- a/src/programs.asm
+++ b/src/programs.asm
@@ -52,6 +52,24 @@ ProgHello:
 SECTION "prog_chello", ROMX[$4000], BANK[5]
 ProgChello:
     INCBIN "c/chello.bin"
+SECTION "prog_echo",   ROMX[$4000], BANK[6]
+ProgEcho:
+    INCBIN "c/echo.bin"
+SECTION "prog_true",   ROMX[$4000], BANK[7]
+ProgTrue:
+    INCBIN "c/true.bin"
+SECTION "prog_false",  ROMX[$4000], BANK[8]
+ProgFalse:
+    INCBIN "c/false.bin"
+SECTION "prog_uname",  ROMX[$4000], BANK[9]
+ProgUname:
+    INCBIN "c/uname.bin"
+SECTION "prog_pid",    ROMX[$4000], BANK[10]
+ProgPid:
+    INCBIN "c/pid.bin"
+SECTION "prog_cat",    ROMX[$4000], BANK[11]
+ProgCat:
+    INCBIN "c/cat.bin"
 
 ; -----------------------------------------------------------------------------
 ; PROG_SH (bank 3) - a tiny shell.
@@ -72,6 +90,8 @@ ProgSh:
     ld c, SYS_READ
     rst $30                     ; A = input byte
     pop hl
+    cp $04
+    jr z, .eof                  ; Ctrl-D / EOF: exit the shell
     cp $0D
     jr z, .eol
     cp $0A
@@ -85,6 +105,11 @@ ProgSh:
     cp LOW(SH_LINEBUF) + SH_MAXLINE - 1
     jr c, .rd                   ; keep reading unless the buffer is full
 
+.eof
+    ld b, 0
+    ld c, SYS_EXIT              ; exit init/shell -> system idle
+    rst $30
+
 .eol
     ld [hl], 0                  ; NUL-terminate
     ld de, .crlf
@@ -93,8 +118,24 @@ ProgSh:
     rst $30
     ld a, [SH_LINEBUF]
     or a
-    jr z, .prompt               ; empty line
+    jp z, .prompt               ; empty line
+
+    ; split off the first word: replace the first space with a NUL so command
+    ; matching sees just the command, and the args survive at SH_LINEBUF+n
+    ; (inherited by the child through fork, read back via main(char *args)).
+    ld hl, SH_LINEBUF
+.split
+    ld a, [hl]
+    or a
+    jr z, .lookup               ; no space -> no args
+    cp $20
+    jr z, .cut
+    inc hl
+    jr .split
+.cut
+    ld [hl], 0                  ; isolate the command word
 
+.lookup
     ; look the command up in the table
     ld de, .cmdtab
 .scan
@@ -122,7 +163,7 @@ ProgSh:
     jr z, .exec
     ld c, SYS_WAIT              ; parent: reap the command
     rst $30
-    jr .prompt
+    jp .prompt
 .exec
     ld a, [SH_PROGID]
     ld b, a
@@ -134,7 +175,7 @@ ProgSh:
     ld b, 3
     ld c, SYS_WRITE
     rst $30
-    jr .prompt
+    jp .prompt
 
 .ps1
     db "$ "
@@ -149,6 +190,18 @@ ProgSh:
     db PROG_HELLO
     db "chello", 0
     db PROG_CHELLO
+    db "echo", 0
+    db PROG_ECHO
+    db "true", 0
+    db PROG_TRUE
+    db "false", 0
+    db PROG_FALSE
+    db "uname", 0
+    db PROG_UNAME
+    db "pid", 0
+    db PROG_PID
+    db "cat", 0
+    db PROG_CAT
     db 0                        ; terminator
 
 ; -----------------------------------------------------------------------------
@@ -191,3 +244,15 @@ ProgramTable::
     dw ProgHello
     db LOW(BANK(ProgChello)), HIGH(BANK(ProgChello))
     dw ProgChello
+    db LOW(BANK(ProgEcho)), HIGH(BANK(ProgEcho))
+    dw ProgEcho
+    db LOW(BANK(ProgTrue)), HIGH(BANK(ProgTrue))
+    dw ProgTrue
+    db LOW(BANK(ProgFalse)), HIGH(BANK(ProgFalse))
+    dw ProgFalse
+    db LOW(BANK(ProgUname)), HIGH(BANK(ProgUname))
+    dw ProgUname
+    db LOW(BANK(ProgPid)), HIGH(BANK(ProgPid))
+    dw ProgPid
+    db LOW(BANK(ProgCat)), HIGH(BANK(ProgCat))
+    dw ProgCat
-- 
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