3182da3965
Claude Code keeps per-project memory at <home>/.claude/projects/<key>/,
where <key> is the project's absolute path with every separator and the
drive colon turned into a dash. That makes it both rename-fragile and
machine-specific, and this project has hit each of those once:
- D:\DEV\Schunix -> D:\DEV\SchOS changed the key, and 43 memories were
invisible until moved across by hand.
- Development happens from Windows and from Linux, and each looks in a
different place for the same checkout.
Committing .claude/memory/ fixes both -- git carries it across renames
and between hosts -- and `import` puts it wherever the local machine
expects. .claude/settings.local.json stays ignored: those are per-machine
permissions.
The colon maps to a dash rather than being dropped. Deleting it gives
D-DEV-SchOS, which matches nothing and silently finds zero memories; that
was the first attempt. On Git Bash the key comes from `cygpath -w`,
because Claude Code is a Windows program and sees D:\DEV\SchOS, not
/d/DEV/SchOS.
2.9 KiB
| name | description | metadata | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| schunix-network-stack-choice | Don't write TCP from scratch — and don't take NetBSD's either; the licence and porting evidence for lwIP vs FreeBSD. |
|
Decided 2026-08-08. Nexoniarz: "we should take FreeBSD or NetBSD and their Network stuff because it's going to be hell making own TCP/IP." Agreed on the premise — TCP is the one part of a network stack where writing it yourself is a bad trade. It is not the packet format that is hard; it is congestion control, retransmission, window management and twenty years of corner cases that only appear against a real peer.
But the source matters, and NetBSD is the wrong one.
The licence evidence (all verified, not assumed)
| advertising clause? | |
|---|---|
NetBSD sys/netinet/tcp_input.c, tcp_output.c |
Yes — the WIDE Project's 4-clause |
FreeBSD sys/netinet/tcp_input.c |
No — UC, Swinburne, FreeBSD Foundation, Juniper |
| lwIP | No — BSD-3, Swedish Institute of Computer Science |
The NetBSD clause belongs to WIDE, not Berkeley, so the 1999 rescission does
not reach it. Checked FreeBSD's file directly from raw.githubusercontent.com;
zero matches for "All advertising materials". Checked lwIP's COPYING; likewise
zero. This reverses the older assumption in docs/roadmap.md that NetBSD
was the intended starting point.
The porting evidence, which matters more
FreeBSD's sys/netinet is not a library. tcp_input.c alone is 122 KB and
reaches into mbufs, epoch(9), netisr, VNET, uma(9), sockbufs, inpcb hash
tables and FreeBSD's locking. Taking it means porting FreeBSD's kernel
infrastructure first and finding the TCP underneath — the same conclusion
docs/roadmap.md §1 already reached about sys/dev/usb.
lwIP was written for the situation Schunix is actually in: a small OS with a raw Ethernet driver and no infrastructure. Port layer is a handful of files, no dependency on the host allocator or locking, and it brings ARP, IPv4, ICMP, UDP, TCP, DHCP and DNS.
Recommendation: lwIP first, FreeBSD as the reference to check against.
Practical notes
- Nexoniarz deleted the NetBSD checkout (
src-trunk/) for space and said it can be re-fetched. Do not clone a whole BSD tree — a sparse checkout ofsys/netandsys/netinetis all that has ever been needed, and the space complaint was legitimate. - One-file fetches from
raw.githubusercontent.comare enough for a licence check and cost nothing. That is how both findings above were made. - Shell trap hit while doing this:
grep -cexits 1 when it finds zero matches, socmd && grep -c ... || echo "failed"prints the failure message on a perfectly successful run. Nearly reported "no network access" when the fetch had worked. - Whichever is chosen, it needs a
NOTICEentry — see schunix-licensing.