Upgrading Linux Kernel on Gentoo Sparc64

We had a troublesome upgrade of our Gentoo Sparc64 box. After emerge world the system wouldn't boot because the boot files were changed without re-running SILO. We fixed this in this article. Anyway, even though we went through this trouble, it appears that the emerge downloaded the 2.4.31 sources, messed with our boot files, but we were still running on 2.4.27.
srv-1 linux # uname -a
Linux srv-1 2.4.27-sparc #1 SMP Fri Jul 18 08:43:34 PST 2008 sparc64
sun4u TI UltraSparc II (BlackBird) GNU/Linux
srv-1 linux #

We decided to recompile the kernel and call it something different. We'll see if emerge will mess with that next time around. Here is how we upgraded our kernel:

srv-1 src # ls
linux linux-2.4.27-sparc linux
srv-1 src # rm linux
srv-1 src # ln -s linux linux
srv-1 src # cd linux

Note that the whole linking of linux to the kernel source tree is dated and not used, supposedly, but we didn't do this originally, it was part of the Gentoo install. Perhaps it still isn't needed, but we aren't willing to change something that mostly works. Let's continue on with copying the old .config file:

srv-1 linux # cp ../linux-2.4.27-sparc/.config ./
srv-1 linux # make oldconfig
rm -f include/asm
( cd include ; ln -sf asm-sparc64 asm)
/bin/sh scripts/Configure -d arch/sparc64/config.in
#
# Using defaults found in .config
.
.
.
* Grsecurity
*
Grsecurity (CONFIG_GRKERNSEC) [N/y/?]
*** End of Linux kernel configuration.
*** Check the top-level Makefile for additional configuration.
*** Next, you must run 'make dep'.

Time to compile:

srv-1 linux # make dep && make clean vmlinux image modules modules_install
.
.
.
make[1]: Leaving directory `/usr/src/linux-2.4.31-sparc/arch/sparc64/math-emu'
cd /lib/modules/2.4.31-sparc; \
mkdir -p pcmcia; \
find kernel -path '*/pcmcia/*' -name '*.o' xargs -i -r ln -sf ../{} pcmcia
if [ -r System.map ]; then /sbin/depmod -ae -F System.map 2.4.31-sparc; fi
srv-1 linux-2.4.31-sparc #

Let's install the kernel and reboot:

srv-1 linux-2.4.31-sparc # cp arch/sparc64/boot/image /boot/sparckernel-2.4.31
srv-1 linux-2.4.31-sparc # cp System.map /boot
srv-1 linux-2.4.31-sparc # vi /etc/silo.conf
srv-1 linux-2.4.31-sparc # silo
/etc/silo.conf appears to be valid
srv-1 linux-2.4.31-sparc #

Let's reboot. [screen gets wavy... flash forward]:
srv-1 ~ # uname -a
Linux srv-1 2.4.31-sparc #1 SMP Sun Jul 19 06:05:28 PDT 2008 sparc64 sun4u
TI UltraSparc II (BlackBird) GNU/Linux
srv-1 ~ #
srv-1 ~ # cat /etc/silo.conf
partition = 1
timeout = 150
default=Gentoo
root = /dev/sda1
image = /boot/sparckernel-2.4.31
label = Gentoo
root = /dev/sda1
read-only
other = /sbus@1f,0/SUNW,fas@e,8800000/sd@9,0;1
label = solaris

All is good.