[coreboot] Lenovo X200 running Coreboot drains 3-4W more power than with Vendor BIOS

[Daniel Kulesz]

Hi Andrey and lynxis,

thank you for the quick reply and your suggestions. I followed Andrey's advice and here are the results (only with full screen brightness):

Coreboot with idle=poll: 15,8W
Coreboot running "stress": 37,2W

Vendor BIOS with idle=poll: 15W
Vendor BIOS with intel_pstate=disabled: 10W
Vendor BIOS running "stress": 24,3W (!!)

Remember, the idle values without additional kernel parameters were:
Vendor BIOS: 10W
Coreboot: 13,4W

I didn't expect the power consumption in the "stress" scenario to rise up that high with coreboot, I just supposed to power consumption in idle to be affected! :-(

Unfortunately, I was not able to extract the VGA BIOS and use it instead of native gfx init, as I didn't succeed to apply bios_extract:

daniel at compilehost:~/extract_x200_vga$ dd bs=1k skip=6144 if=x200_factory.rom of=x200_biospart.img
2048+0 records in
2048+0 records out
2097152 bytes (2.1 MB, 2.0 MiB) copied, 0.00409209 s, 512 MB/s
daniel at compilehost:~/extract_x200_vga$ ../bios_extract/bios_extract x200_biospart.img 
Using file "x200_biospart.img" (2048kB)
Error: Unable to detect BIOS Image type.

And I didn't find any documentation about how to actually extract the VGA Bios part, so any hints are welcome.

By the way: All settings in the vendor BIOS are default/unchanged. And I activated all these PCI power management and ASPM settings in coreboot (see my attached config) and even disabled all debugging to serial console etc. but this didn't help so far.

Cheers, Daniel
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