Re: Configuring Tianocore Logging

[Laszlo Ersek <lersek@redhat.com>]

On 11/14/16 19:27, Janne Heß wrote:
> Hello everyone,
> 
> I'm currently trying to get Tianocore running as a coreboot payload, but
> it just resets the machine, so I tried to increase the log level.
> As a EDK II newbie, it's really hard to figure out where to raise the
> log level.
> I found  the Debug FAQ which tells me about PcdDebugPropertyMask and
> PcdDebugPrintErrorLevel.
> So I looked the values up and found that they are set in MdePkg/MdePkg.dsc.
> After setting these to 0xff... I rebuilt but there is still no output at
> all. I also switched the TARGET to DEBUG, but it doesn't help.
> So what am I missing here?
> I tried building both Ovmf and the Coreboot payload, but neither of them
> logs anything.

Generally:

You need a DebugLib library instance that logs to a device that you can
observe.

The most common such DebugLib instance is

MdePkg/Library/BaseDebugLibSerialPort/BaseDebugLibSerialPort.inf

which writes to the serial port.

In turn that depends on "SerialPortLib", which is really
platform-specific. Two examples are:

PcAtChipsetPkg/Library/SerialIoLib/SerialIoLib.inf
ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf

Specifically:

- For capturing the OVMF debug log with QEMU, please look at OvmfPkg/README.

- For CoreBoot*Pkg, I guess
<https://github.com/tianocore/tianocore.github.io/wiki/Coreboot_UEFI_payload>
is the documentation.

Thanks
Laszlo