[SSI-devel] BUG: Large ramdisks break ELF image

[Brian J. W. <Bri...@hp...>]

Etherboot developers,

In our OpenSSI clustering project, we support Etherboot as one of the 
methods to network boot a node that is not directly attached to the 
shared root filesystem. Recently we've noticed that mknbi-linux is 
complaining that it will be end-of-lifed, and that we should switch to 
using mkelf-linux.

Unfortunately, the image generated by mkelf-linux does not seem to be 
usable by an Etherboot 5.2.2 floppy image, at least not one for the 
eepro100 chipset. The symptom is that Etherboot successfully downloads 
the image, reports that it has detected a ramdisk image of a certain 
size (0x18E000) and loaded it into high memory (ending at 0xC000000, 
IIRC), then it hangs. There are no error messages.

OpenSSI uses relatively large ramdisks (~1.5M compressed). As an 
experiment, I built an ELF image with the same OpenSSI kernel and a 
smaller ramdisk. Etherboot had no problem with it, so the bug seems to 
be sensitive to ramdisk size.

It's possible that this bug was recently introduced. One of our 
developers was using an Etherboot floppy that he made nearly a year ago, 
and he didn't have any problems with ELF images of OpenSSI kernels and 
ramdisks.

Let me know if you need any more information.

Thanks,

Brian