etherboot dosen't find my elfkernel

Eric W. Biederman ebiederman at lnxi.com
Fri Apr 25 20:12:00 CEST 2003


Richard Smith <rsmith at bitworks.com> writes:

> I've got etherboot loading now.
> 
> I took a bzImage and turned it into a elfimage with
> 
> mkelfimage bzImage elfimage
> 
> using mkelfimage 2.5

Yeah.  At least someone does not have broken binutils :)
 
> then stuck that on my CF in the first partition ie 'cat elfimage > /dev/hde1'
> where hde is the pcmcia mount of my CF
> 
> Stick it in my target and boot.
> 
> I get:
> 
> < linux bios stuff snipped>
> 
> Etherboot 5.1.8 (GPL) Tagged ELF for [IDE]
> Relocating _text from: [00023d20,00032e30) to [07ff0ef0,08000000)
> Probing pci disk...
> [IDE]disk-1 7872k cap: 0200
> Searching for image...
> ................................<abort>
> Probing pci disk...
> [IDE]Probing isa disk...
> <sleep>
> Probing pci disk...
> [IDE]disk0 7872k cap: 0200
> Searching for image...
> ................................<abort>
> Probing pci disk...
> [IDE]Probing isa disk...
> <sleep>
> Probing pci disk...
> [IDE]disk1 7872k cap: 0200
> Searching for image...
> ................................<abort>
> Probing pci disk...
> [IDE]Probing isa disk...
> <sleep>
> 
> And it just goes on and on checking different disks
> 
> Did I miss something?  Is Tagged ELF different from the elf image that I created
> with mkelfimage?

Nope. the file format is right.

Etherboot just works the way the LinuxBIOS code originally did.

In particular it scans the first 8K of disk for an ELF header.
This means you don't have to be at the absolute start of the disk
for your ELF image you do need to be close.  

Think of what is happening as a super master boot record
instead of a stupid bootloader.  As there is a very strong
reluctance to upgrade firmware I try to make the as simple as possible
while still being powerful enough to be useful.   Hopefully at some
point there a bootloader I can read off of the disk.  

With the appropriate tools it is possible to force your first
partition early in the disk.  By default the first partition is
often aligned on a cylinder boundary, which is probably
what you are running into.

The fact the IDE driver is reading your disk and not having problems
is good.


Eric




More information about the coreboot mailing list