[coreboot] Intel Baytrail E3845 Coreboot - Not booting after modifying CMOS boot_option

Nico Huber nico.h at gmx.de
Thu Oct 13 22:54:06 CEST 2016

Hello Mohan,

On 13.10.2016 09:14, Mohan Shanmuga Sundaram wrote:
> Dear Coreboot Community!
> I have modified the following CMOS option table bit using 'nvramtool'
> utility from Ubuntu:
> 384          1       e       4        boot_option
> Its default value was 'Normal', which I modified to 'Fallback'. After
> rebooting, the coreboot seems to be not loading the default payload.
> In what way I can recover it?
> Where does the CMOS modification resides?
this all heavily depends on the version of coreboot you are using and
the configuration. See https://www.coreboot.org/Fallback_mechanism for
the (hopefully) current state.

> I have redone the coreboot.rom flashing completely, yet the coreboot
> didn't load the default payload.
I can see only one payload in your CBFS. To clarify, is it booting any
payload at all?

> The following is my CBFS:
> Performing operation on 'COREBOOT' region...
> Name                           Offset     Type         Size
> cbfs master header             0x0        cbfs header  32
> fallback/romstage              0x80       stage        30868
> cpu_microcode_blob.bin         0x7980     microcode    208896
> fallback/ramstage              0x3aa00    stage        51629
> config                         0x47400    raw          749
> revision                       0x47740    raw          575
> cmos_layout.bin                0x479c0    cmos_layout  1212
> pci8086,0f31.rom               0x47ec0    optionrom    65536
> fallback/dsdt.aml              0x57f40    raw          12527
> fallback/payload               0x5b080    payload      61165
> payload_config                 0x69fc0    raw          1563
> payload_revision               0x6a640    raw          243
> (empty)                        0x6a780    null         1333016
> fsp.bin                        0x1afec0   fsp          294912
> (empty)                        0x1f7f00   null         30168
> bootblock                      0x1ff500   bootblock    2480
The general idea is that you can switch between files below fallback/
and normal/. But there is only fallback/ in your image.

> Regards,
> Mohan
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