6. Installation of Linux/MIPS and common problems.

6.1 NFS booting fails.

Usually, the reason for this is that people have unpacked the tar archive under IRIX, not Linux. Since the representation of device files over NFS is not standardized between various Unices, this fails. The symptom is that the system dies with the error message ``Warning: unable to open an initial console.'' right after mounting the NFS filesystem.

For now, the workaround is to use a Linux system (doesn't need to be MIPS) to unpack the installation archive onto the NFS server. The NFS server itself may be any type of UNIX.

6.2 Self-compiled kernels crash when booting.

When I build my own kernel, it crashes. On an Indy the crash message looks like the following (the same problem hits other machines as well but may look completely different):

   Exception: <vector=UTLB Miss>
   Status register: 0x300004803<CU1,CU0,IM4,IPL=???,MODE=KERNEL,EXL,IE>
   Cause register: 0x8008<CE=0,IP8,EXC=RMISS>
   Exception PC: 0x881385cc, Exception RA: 0x88002614
   exception, bad address: 0x47c4
   Local I/O interrupt register 1: 0x80 <VR/GIO2>
   Saved user regs in hex (&gpda 0xa8740e48, &_regs 0xa8741048):
     arg: 7 8bfff938 8bfffc4d 880025dc
     tmp: 8818c14c 8818c14c 10 881510c4 14 8bfad9e0 0 48
     sve: 8bfdf3e8 8bfffc40 8bfb2720 8bfff938 a8747420 9fc56394 0 9fc56394
     t8 48 t9 8bfffee66 at 1 v0 0 v1 8bfff890 k1 bad11bad
     gp 881dfd90 fp 9fc4be88 sp 8bfff8b8 ra 88002614

   PANIC: Unexpected exception
  

This problem is caused by a still unfixed bug in Binutils newer than version 2.7. As a workaround, change the following line in arch/mips/Makefile from:

   LINKFLAGS       = -static -N
 

to:

   LINKFLAGS       = -static
 

6.3 Booting the kernel on the Indy fails with PROM error messages

   >> boot bootp()/vmlinux
   73264+592+11520+331680+27848d+3628+5792 entry: 0x8df9a960
   Setting $netaddres to 192.168.1.5 (from server deadmoon)
   Obtaining /vmlinux from server deadmoon

   Cannot load bootp()/vmlinux
   Illegal f_magic number 0x7f45, expected MIPSELMAGIC or MIPSEBMAGIC.
  

This problem only happens for Indys with very old PROM versions which cannot handle the ELF binary format which Linux uses. A solution for this problem is in the works.

6.4 Where can I get the little endian firmware for my SNI?

SNI's system can be operated in both big and little endian modes. At this time, Linux/MIPS only supports the little endian firmware. This is somewhat unlucky since SNI hasn't shipped that firmware for quite some time, since they dropped Windows NT.

When running in big endian mode, the firmware looks similar to an SGI Indy which is already supported, therefore fixing the SNI support will be relatively easy. Interested hackers should contact Ralf Bächle (ralf@gnu.org).

6.5 ld dies with signal 6

   collect2: ld terminated with signal 6 [Aborted]
 

6.6 My machine doesn't download the kernel when I try to netboot

Your machine is replying to the BOOTP packets (you may verify this using a packet sniffer like tcpdump or ethereal), but doesn't download the kernel from your BOOTP server. This happens if your boot server is running a kernel of the 2.3 series or higher. The problem may be circumvented by doing a "echo 1 > /proc/sys/net/ipv4/ip_no_pmtu_disc" as root on your boot server.

6.7 Bug in DHCP version 2

When using DHCP version 2 you might see the following problem: Your machines receives it's BOOTP reply 3 times but refuses to start TFTP. You can fix this by doing a "unsetenv netaddr" in the PROM command monitor before you boot your system. DHCP version 3 fixes that problem.