Basic Alpha Patch & Kernel Notes & Info
	by Harvey J. Stein


Facts:
   1. Stock kernel headers are *not* compatible with the glibc headers that
      comes with Redhat alpha 4.2 (which is glibc 1.9).
   2. Stock kernel headers are compatible with the glibc2 headers.
   3. glibc2 is not compatible with the binaries that come with Redhat
      alpha 4.2.
   4. The kernel RPM from Redhat 4.2 patches the kernel headers to make it
      compatible with glibc 1.9.
   5. The other available kernel patches (except as noted below) also
      make the kernel compatible with glibc 1.9.

Patch descriptions:

Note - All patches are to be applied to a pristine 2.0.30, except as noted. 


   ftp://ftp.azstarnet.com/pub/linux/axp/sys/axp-diffs-2.0.30.gz
      -Various fixes for 2.0.30.
      -Modifies the kernel headers to make them compatible with glibc
       1.9.

   ftp://ftp.digital.com/pub/DEC/Linux-Alpha/em86/v0.2/kernel-patches/alpha-patches-2.0.30-0.2a.gz
      -Includes the above, plus additional bug fixes, plus
       enhancements needed for em86.
      -Breaks trap handling - running programs with lots of unaligned
       access could crash the machine.

   Kernel which comes with Redhat 4.2:
      -A patched version of 2.0.30.  Kernel headers are patched to be
       compatible with glibc 1.9 headers.  Includes some, but not all
       of alpha-patches-2.0.30-0.2a.gz, but *does* include the trap
       handling bug.

   ftp://genie.ucd.ie/pub/alpha/kernel/alpha-patchset.tar.gz
      -Includes several patches:
          alpha-patches-0.2-glibc2.diff
              -This is alpha-patches-2.0.30-0.2 (*not* 0.2a), but
               modified to apply to 2.0.30-pre.10, except that it
               *doesn't* modify kernel headers for glibc 1.9.
          ap-0.2-fixes-1.diff
              -Fixes to alpha-patches-0.2-glibc2.diff.  In particular,
               fixes the trap handling.


Kernel compilation possibilities:

   1. Using stock kernels on RH 4.2 systems:

      The stock kernel headers are incompatible with the
      supplied glibc.  However, you can work around this by leaving
      the symlink in /usr/src/linux pointing to the kernel source tree
      that comes with RH 4.2.

   2. Using patches from ftp.azatartnet.com or ftp.digital.com:

      Apply one or the other, but *not* both to a pristine 2.0.30,
      *not* the 2.0.30 that comes with Redhat 4.2.

   3. Using patches from genie.ucd.ie:

      Get the original 2.0.30 and apply 2.0.30-pre.10 first.  Then you
      can apply alpha-patches-0.2-glibc2.diff, and if you desire, you
      can also apply ap-0.2-fixes-1.diff, or components of it which
      are available on the ftp server.  See the ftp server for details.
      If you do this, you either need to be using glibc2 or you need
      to leave the /usr/src/linux symlink pointing at the old kernel
      source tree.

   4. 2+3 combo:

      You can apply alpha-patches-2.0.30-0.2a.gz from ftp.digital.com
      to a pristine 2.0.30, and then apply ap-0.2-fixes-1.diff.  This
      seems to work fine, and the kernel header files should be
      compatible with redhat 4.2 (although I've left /usr/src/linux
      pointing to the old tree anyway).  If you do this, then you'll
      get one reject from the ap-0.2-fixes-1.diff patch.  I think
      applying it by hand should be ok.  Just added result = -EIO; to
      the NOT_READY & ILLEGAL_REQUEST cases in drivers/scsi/sr_ioctl.c.


   WARNING - Remember that kernel sources unpack into /usr/src/linux, so
   if you have a /usr/src/linux symlink, you'll need to remove it, unpack
   the kernel, and put back the symlink.



Kernel compilation details:

   It seems that with the Redhat glibc one can use both unpatched and
   patched kernels, as long as one keeps a /usr/src/linux symlink to
   the Redhat kernel source tree.  So, we get the following procedure
   for those using Redhat's glibc (glibc 1.9).  Those brave enough to
   use glibc2 can probably figure out what they need to do on their
   own or via the glibc2 HowTos.

   Step by step notes:

   0. cd to the /usr/src directory.
   1. If you have a linux symlink, remove it.  If you have a linux
      subdirectory, rename it to something like linux-redhat.  If you
      have something else there, I'll call it linux-redhat for the
      rest of these instructions.
   2. Untar linux-2.0.30.tar.gz.
   3. Rename linux to linux-2.0.30.
   4. Make a symlink from linux back to linux-redhat.
   5. cd /usr/src/linux-2.0.30 (for the rest of these instructions).
   5. If you're *not* going to patch the kernel, then edit the
      Makefile, changing ARCH=i386 to ARCH=alpha.
   6. Apply patches as noted above.
   7. make mrproper
   8. make xconfig
         This seems to work for me, except that tkparse complains
         about not recognizing the "unset" commands in
         arch/alpha/config.in.  I don't know how serious this is.
   9. Save to a file if you so desire.
  10. Save & exit.
  11. make dep clean
  12. make boot
  13. cp arch/alpha/boot vmlinux.gz /vmlinux-2.0.30-my-very-own.gz
  14. reboot with /vmlinux-2.0.30-my-very-own.gz.

I hope this helps clarify things, and I hope I got it right.

Good luck,

-- 
Harvey J. Stein
Berger Financial Research
hjstein@bfr.co.il