Re: Debian SID kernel results in "Fast Data Access MMU Miss" on Sun Ultra 30

[Stan Johnson <userm57@yahoo.com>]

Hello,

On 7/31/23 1:06 PM, Stan Johnson wrote:
> ... "Fast Data Access MMU Miss" while loading the initrd

After doing some more testing (and accidentally erasing my system disk
-- sda is the lower drive, not the upper one!), it's looking like the
"Fast Data Access MMU Miss" error is not caused by a kernel issue. I
think the default initrd has blown past some hard-coded memory limit in
SILO for loading the initrd (that's a guess). I'm able to get any kernel
to boot as long as I keep the initrd to less than around 20 MB.

Note: Debian's vmlinux-6.4.0-1-sparc64 kernel can't be created using
Debian's config file config-6.4.0-1-sparc64. The config file has debug
options enabled that result in a 300 MB kernel and over 3 GB of modules.

After re-installing SILO 1.4.14 by installing Debian 7.11 from CD, I
re-learned some interesting things about SILO. Like GRUB, it lives in an
ext2 filesystem (the Sun Boot partition), and it wants to be mounted as
/boot. So by default, SILO is very similar to GRUB. Both silo.conf and
grub.conf can be configured to be static, with no kernels in the Sun
Boot partition, and the Boot partition likely doesn't have to remain
mounted as /boot for GRUB to still work (though I'd probably have to
delete or disable grub-install to manage GRUB manually).

To test the latest GRUB, I downloaded what I thought was the latest
Debian sparc64 snapshot from here:
https://cdimage.debian.org/cdimage/ports/snapshots/2023-06-18/debian-12.0.0-sparc64-NETINST-1.iso

The installation failed with an error regarding Perl -- I didn't save
anything yet because I wanted to make sure I'm using the correct image.
If it's the right image, I'll capture the log file and post it under a
different thread.

One last question regarding Sun partitions: Is the following warning
while using parted important?
"Warning: The disk CHS geometry (562253,255,2) reported by the operating
system does not match the geometry stored on the disk label
(17849,255,63)."
Using fdisk, I don't see a similar error:
# fdisk -l
Disk /dev/sda: 136.73 GiB, 146815737856 bytes, 286749488 sectors
Disk model: ST3146807LC
Geometry: 255 heads, 63 sectors/track, 17849 cylinders
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: sun
Device        Start       End   Sectors   Size Id Type         Flags
/dev/sda1         0    257039    257040 125.5M  1 Boot
/dev/sda2    257040   4257224   4000185   1.9G 82 Linux swap
/dev/sda3         0 286744184 286744185 136.7G  5 Whole disk
/dev/sda4   4257225  20257964  16000740   7.6G 83 Linux native
/dev/sda5  20257965  52259444  32001480  15.3G 83 Linux native
/dev/sda6  52259445  84260924  32001480  15.3G 83 Linux native
/dev/sda7  84260925 286744184 202483260  96.6G 83 Linux native

-Stan