Subject: Kernel CRC
To: None <>
From: Steve Woodford <>
List: tech-kern
Date: 09/17/1999 11:24:37

How feasible would it be to add some form of verification check to the
kernel's bootloader? For example, a CRC over the kernel text and data
which is checked by the bootloader before executing the image.

I ask because I've just spent a day tracking down the cause of a kernel
image corruption on mvme68k. It eventually turned out to be a bizarre SCSI
cable related problem (at least, it went away after reseating the cables
;-), which caused the same five bytes at the same file offsets to be
corrupted with exactly the same corrupt data! At one point, I had exactly
one bootable/working kernel which, although corruption was evident, would
at least get to the login prompt. All other images bombed out during

Anyhow, I would envisage a boot option to disable checking for kernel
images which have been hand-patched, or for older images which don't
contain a CRC.

Any thoughts?

Cheers, Steve