[coreboot] Timing via serial port

Kevin O'Connor kevin at koconnor.net
Sun Apr 19 05:05:53 CEST 2009

On Sat, Apr 18, 2009 at 09:14:06PM -0400, Kevin O'Connor wrote:
> The biggest SeaBIOS time consumers:
> 425ms - scanning for option roms

I tracked this one down - it's the cost of CBFS and reading the flash.
Of the 425ms, 90ms is spent copying the via vga rom.  The remaining
time is spent doing CBFS searches - there are 18 pci devices on this
machine and for each one SeaBIOS scans CBFS for "pciVVVV,DDDD.rom".
Because none of these files were actually present, SeaBIOS ended up
walking all the flash freespace each time.  All those flash accesses
add up.

> 260ms - initializing ATA drives

I wonder if I can skip the ATA reset on the first boot - the device
should have just gone through a hw reset anyway...


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