Add NovaCustom V540TU board

[mkopec]

Add NovaCustom V540TU board (14" V54 Series, Meteor Lake, Integrated graphics)

[macpijan]

@mkopec Do we plan to add here the rest of the variants as well?

[mkopec]

@macpijan sure, after one starts working I'll do the rest too

[tlaurion]

@macpijan @mkopec similar commit needed for #1835

[tlaurion]

@mkopec this comment might be helpful #1835 (comment)

[tlaurion]

@mkopec

mkc: seems like kernel 6.7+ is bare minimal for meteor lake, with efifb fixes having landed under 6.8+?

Also, if you pass serial to kernel boot options under coreboot config, you should get logs of the kernel?

At https://matrix.to/#/!pAlHOfxQNPXOgFGTmo:matrix.org/$bVtsV3M_sz0MroFsDkXRGQ3ow7OhumKqtAllchkAyKs?via=matrix.org&via=nitro.chat&via=envs.net

[mkopec]

mkc: seems like kernel 6.7+ is bare minimal for meteor lake, with efifb fixes having landed under 6.8+?

possible, in Ubuntu and Fedora we found it best to have Linux 6.8 or newer (6.9 also has a fix for s0ix but that's irrelevant for Heads)

@tlaurion do you think you can help with updating the kernel?

[tlaurion]

I read that 6.12 will be next Lts but that is only speculation.

edit: We choose 6.11.9 for all novacustom boards?
I can give it a shot, yes, and leave traces in commit, taking this PR state as a base.

@mkopec did serial console passed per coreboot config to kernel gave you more info?
With debug as well. See qemu coreboot config, non-prod.

[tlaurion]

@mkopec there is a lot to tune under 6.11.9 kernel config which writes over shared linux config with other novacustom (config/linux-nitrokey-x.config, should probably renamed and all board configs point to new name as well).

See branch https://github.com/tlaurion/heads/tree/dasharo-add_novacustom_v540tu and feel free to steal adapt/change whatever. If you have questions, poke me where/if needed.

Note: compare config changes in commit 510bc6e to see all the new olddefconfig stuff applied silently when using defconfig. Ie, what happened with TRUST_CPU and so many other stuff to care about once you have something that boots.

See also that I changed your coreboot config to pass linux kernel options to be in debug, with probably wrong serial ttyS0, adapt accordingly and keep me posted. Small iterations in board porting has known good track history.

If you decided to tackle #1835 instead, I could help (if you guide me into how you get serial console output [even though this work wasn't planned nor in my plate up to now]).

[tlaurion]

• Switched x230 to use 6.11.9 with same process applied for quick testing: success (no brick bumped to 6.11.9).
• building all boards that were depending on linux-x230-maximized.config with kernel 6.11.9 at https://github.com/tlaurion/heads/tree/dasharo-add_novacustom_v540tu_regression-test-on-x230_success-build_test_for_all_x230_dependent_linux_config_from_CI (expecting sandy bridge based boards to fail because bzImage will be too big)

Edit:yep. Cannot bump Sandy to 6.11.9: as can be seen, all those do not have enough free spi space without another phase of #590 (not planned.)

[mkopec]

Thanks for the patches @tlaurion , I'm testing them now, i'm not getting a serial console yet, I suspect the LPSS UART driver is missing, will try to fix

[tlaurion]

@mkopec #1865 merged, please rebase

[tlaurion]

Thanks for the patches @tlaurion , I'm testing them now, i'm not getting a serial console yet, I suspect the LPSS UART driver is missing, will try to fix

@mkopec This needs updates, since reported off-channel to be all good :)