[ipxe-devel] "Installation failed" on 3Com 905B cards

Michael Brown mcb30 at ipxe.org
Sun Mar 31 17:17:34 UTC 2019

On 29/03/2019 21:43, Quinn Plattel wrote:
> I managed to track down the problem.  Looks like a hardware issue on 
> 3com 905B cards that use the Lucent chipset.  Apparently, when the card 
> reads from the rom, only the first 8KB is read.  I found out about this 
> by going back in time to when etherboot was still being developed.  
> There is a file called 3c90x.txt which describes the problem.  This text 
> is also referenced in 3c90x.c in the ipxe sources.  Anyways, etherboot 
> made a bootrom fix so that the card could read 16KB instead of 8KB by 
> changing the NVRAM to use MII on the card as the default.  Of course, 
> when you apply this fix then you must make sure you don't touch the 
> NVRAM after for example by using the 3c90xcfg.exe utility or otherwise 
> you will have to apply the bootrom fix again.  Unfortunately, the 
> variable  CFG_3C90X_BOOTROM_FIX was removed when gPXE came out and iPXE 
> also.  So I compiled the etherboot 3c90x rom file in a floppy bootable 
> format with the bootrom fix variable active as described in the text 
> file.  The result is I can now flash any rom code to the flash rom and 
> it will work properly now.  I have tested both iPXE and the XTIDE rom 
> projects and they both work successfully after applying the fix.

Fantastic; thanks for reporting back on the workaround!


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