From b5544e84232b80351e7c58501c1632080a354d12 Mon Sep 17 00:00:00 2001 From: user Date: Fri, 17 Jul 2026 01:28:23 +0200 Subject: net: SLIP framing over the link port + a host gateway (echo round-trip) First step of link-port networking. The LCD terminal + OSK freed the serial port from console duty, so it can be the network link. Kernel (src/net.asm): raw link-port serial that bypasses the console/ terminal - sys_ssend (transmit, GB drives the clock) and sys_srecv (receive, GB slave, blocks by yielding). Syscalls 29/30. Userland: libc ssend()/srecv(); c/necho.c does SLIP (RFC 1055) framing over them - send a packet, receive the reply, print it. Host: tools/gateway.py wraps the emulator, owns its link serial, speaks SLIP, and (for now) echoes every frame back - the "link cable adapter". Console (ASCII) bytes on the same channel are printed for visibility. Verified: `necho` sends a SLIP frame, the gateway decodes+echoes it, and gbos prints the reply - a real framed round-trip over the Game Boy link port. Next: swap the echo for actual network ops (DNS/HTTP or IRC/chat). --- include/gbos.inc | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/gbos.inc') diff --git a/include/gbos.inc b/include/gbos.inc index bd7fbc2..71d6fa0 100644 --- a/include/gbos.inc +++ b/include/gbos.inc @@ -126,7 +126,9 @@ DEF SYS_MKDIR EQU 25 ; make a directory (DE=path -> A=0/$FF) DEF SYS_CHDIR EQU 26 ; change directory (DE=path -> A=0/$FF) DEF SYS_OPENDIR EQU 27 ; point ls at a directory (DE=path -> A=0/$FF) DEF SYS_PIPE EQU 28 ; make a pipe (-> A=read fd; write=A+1) -DEF SYS_MAX EQU 29 +DEF SYS_SSEND EQU 29 ; link-port: transmit one byte (E=byte) +DEF SYS_SRECV EQU 30 ; link-port: receive one byte (-> A=byte, blocks) +DEF SYS_MAX EQU 31 ; SYS_KILL (9) is now implemented (B=pid -> A=0/$FF; pid 1 is immortal) ; (SYS_OPEN=4 / SYS_CLOSE=5 are now implemented by the filesystem) @@ -211,5 +213,6 @@ DEF PROG_BLK EQU 19 DEF PROG_MKDIR EQU 20 DEF PROG_COUNT EQU 21 DEF PROG_PTEST EQU 22 +DEF PROG_NECHO EQU 23 ENDC -- cgit v1.3.1-sl0p