| Commit message (Collapse) | Author | Files | Lines |
|---|
|
Refactor netd into a protocol dispatcher (IP -> ICMP/UDP) and add UDP echo:
swap addresses + ports and recompute the UDP checksum over the pseudo-header
(src/dst IP + proto + length) plus the datagram. This is the same pseudo-
header TCP uses, so it de-risks the next milestone.
tools/gateway.py --mode udp sends a datagram and verifies the echo.
Verified: 'hello udp gbos' echoes back with cksum=ok.
|
|
Start of an actual TCP/IP stack on gbos (TLS stays in a proxy). netd is a
userland IP responder over SLIP: our address is 10.0.0.2, the SLIP peer
10.0.0.1. It parses IPv4 headers, answers ICMP echo requests, and rebuilds
the packet with correct IP + ICMP checksums (RFC 1071 one's-complement sum,
carry-folded - works fine on the SM83).
c/netd.c + register; tools/gateway.py gains --mode ping: it crafts ICMP echo
requests over SLIP and verifies the replies.
Verified: `netd` answers 4 pings, gateway reports reply from 10.0.0.2 with
cksum=ok for each. Next: UDP, then TCP.
|
|
The application layer of the link-port demo, and it ties the whole system
together: the LCD terminal displays, the on-screen keyboard types, and the
link port carries a live chat.
Kernel: sys_srecv_nb (non-blocking link receive; A=byte, CF=none) and
sys_pollin (poll the OSK for a typed char without blocking) - syscalls
31/32. Both are what a poll loop needs to receive and type at once.
Userland: c/chat.c runs a poll loop - it feeds non-blocking bytes through a
SLIP receive state machine and prints whole incoming frames as messages,
while pollin() drives the on-screen keyboard; SELECT shows the keys, type a
line, START sends it as a frame. libc srecv_nb()/pollin().
Host: tools/gateway.py --mode chat is a simple bot peer (echoes each GB
message and injects a few async ones); --keys can drive the OSK for tests.
Verified: the gateway pushes 'welcome', '<alice> hey gameboy!', '<bob> nice
link cable' unprompted and the GB displays all three (async receive); typing
'hi' on the OSK echoes it and emits the SLIP frame \xC0hi\xC0 (send). A Game
Boy in the chat, keyboard on screen, over the link cable.
|
|
Grow the link-port demo from echo to actual network access. The Game Boy
still only does SLIP framing + display; the host gateway does DNS/TCP/HTTP.
- c/netlib.h: SLIP framing factored out (header-only, per-program copy).
necho.c now uses it too.
- c/wget.c: `wget URL` frames the URL, then prints the reply body. The
gateway streams the body back as typed frames: 'D'<chunk> ... 'E'.
- tools/gateway.py: add --mode http (urlopen the frame as a URL, cap the
body, chunk it) alongside --mode echo; --cmd runs any gbos command.
Verified: `wget example.com` streams back the full Example Domain HTML onto
the terminal; `wget sl0p.foo` fetches the real page. A Game Boy on the web,
over the link cable.
|
|
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).
|
