[coreboot] [skylake] Can not turn monitor on

[Nico Huber]

Hi Zheng,

On 10/6/18 4:58 AM, Zheng Bao wrote:
> Sorry for being unclear.

no worries, it seems I wasn't very attentive anyway. I just implied
you have an integrated (laptop) panel; maybe because you have a mobile
processor or maybe because the 1440x900 resolution is common for lap-
tops. Anyway, now that you mentioned VGA...

May I assume that you don't have an integrated panel and just want an
external VGA monitor to work?

> By BIOS stage,  I mean I need to see the text "Press ESC for boot menu."
> on screen. It also means it needs to boot DOS with display on.
> But I can not. I have to wait for the linux to boot. Only Linux
> (driver?) can turn the display on. I tried with both vbt from github and

The VBT is a configuration file for the VBIOS/GOP and graphics drivers.
It has to be adapted for each board, so the one from github would only
work by low chance.

> extracted from  original AMI BIOS.

How did you extract it? using uefitool on a BIOS image? or from RAM when
the original BIOS booted?

> My board uses IT6515FN to transfer the display to VGA.

This sounds like something libgfxinit could support. I would just try
it. You'd have to enable support for your board like this [1]. Your
`Port_List` should be `(DP1, DP2, DP3, Internal)`. `Internal` means the
eDP here. If you know exactly to which physical port this IT6515FN is
connected, you can also specify only that port. Then, in your .config
you should have:

  CONFIG_MAINBOARD_USE_LIBGFXINIT=y
  CONFIG_VGA_TEXT_FRAMEBUFFER=y

If you try that and it fails, please also enable

  CONFIG_DEBUG_ADA_CODE=y

and send us a coreboot log.

Nico

[1] https://review.coreboot.org/28620