This lab will be short; we will add all network modules needed for network layout and make a roadmap how to make the Raspberry Pi ethernet driver. First have a look at other ports and inferno and find what is needed to compile with network support.

  1. dev section needs:
+       ip  ip ipv6 ipaux iproute arp netlog ptclbsum iprouter plan9 nullmedium pktmedium netaux
+       ether netif netaux
  1. add ip section
+       il
+       tcp
+       udp
+       ipifc
+       icmp
+       icmp6
  1. mod section needs:
+       crypt
+       ipints

Then we will add etherusb.c from 9pi project (according to 9pi: it takes over the job of copying packets between the usb pipe and the kernel ether i/o queues, to save the extra overhead of doing it in user mode in the usb/ether driver.) Later we may not need it, but for now take it just to have complete compilation.

Then link section:

+       etherusb
+       ethermedium
+       loopbackmedium

In archpi.c we will add ethernet initialization:

 #include "dat.h"
 #include "fns.h"
+#include "../port/netif.h"
+#include "etherif.h"
 static void
 validaddr(void*, ulong, int) {}
+archether(unsigned ctlrno, Ether *ether)
+    switch(ctlrno) {
+    case 0:
+        ether->type = "usb";
+        ether->ctlrno = ctlrno;
+        ether->irq = -1;
+        ether->nopt = 0;
+        ether->mbps = 100;
+        return 1;
+    }
+    return -1;
+ * stub for ../omap/devether.c
+ */
+isaconfig(char *class, int ctlrno, ISAConf *isa)
+    USED(ctlrno);
+    USED(isa);
+    return strcmp(class, "ether") == 0;

That’s enough for now. We can compile everything, we will have appropriate modules, but no ethernet driver yet. As next actions I see two ways of implementing/porting it.

  1. Raspberry Pi Usb driver for Plan9 written in C to be ported to Limbo
  2. Raspberry Pi Usb driver for Plan9 written in C just used as some fileserver which is initialized from Usb Limbo layout (which /dev/usb files to use to read/write, etc)