[coreboot] Problems changing payload on Intel Leaf Hill

[Nico Huber]

Hi Tahnia,

On 10.10.2017 10:29, Tahnia Lichtenstein wrote:
> ...
> 
> Then I built this version of coreboot with a self-compiled payload, such as
> Tianocore UDK2017 CorebootPayloadPkg or SeaBIOS, using the .confg files
> provided by Intel for UEFI payloads or legacy payloads respectively (just
> modified for specific payload type and path, and disabling verified and
> measured boot). I stitched the coreboot output with the Intel-provided
> blobs using the exact same method as before. Then, in run-time, coreboot
> transitions to the payload and nothing happens from then on (i.e. no
> further serial debug messages, no change to display monitor).

you've only attached config files for your coreboot but not for the
payloads. It's hard to tell what output to expect without that (e.g.
do you have serial output enabled in your SeaBIOS build? if you let
the coreboot build environment configure SeaBIOS it is enabled expli-
citly). So with the current information you've provided, it could
just be that the payloads don't try to output anything on serial.

Output on a monitor is a little more complicated and depends on each
payload. SeaBIOS expects a Video BIOS to be present. This can either
be an option ROM from a gfx adapter card (looking at your logs, you
don't seem to have one), a Video BIOS file in CBFS matching the inte-
grated gfx adapter, or, in case coreboot already configured a frame-
buffer, a Video BIOS shim called SeaVGABIOS (aka. cbvga in this case,
it's a separate component in the SeaBIOS source).

Current CorebootPayloadPkg *should* be able to use a preconfigured
framebuffer. I never tried it, though, and there are reports that it
doesn't always work... It's generally possible that Intel's precom-
piled UEFI payload has it's own gfx driver (GOP) built in.

> ...
> Am I not specifying the correct configuration options for Tianocore and
> SeaBIOS? I.e. is there more to it than just selecting the payload type and
> specifying the payload path? Do I need to configure or update memory
> addresses or ranges to match payload sizes, or some such? Do I need to make
> specific changes to the payloads' source code to support the platform? Any
> advice on how/where to start debugging?

Usually there is nothing more to specify. The best option, IMO, is to
get one of the simpler payloads (SeaBIOS should do) to output on serial.
You can also test your SeaBIOS binary in QEMU to make sure it does out-
put something.

Hope that helps,
Nico