x230: remove 4M and 8M split-images from the build

[merge]

The bios regions of the 12M coreboot image is 7M: 4M and 3 of the 8M split
image. The rest of the 8M image generated with fake data and not usable
on real systems! It's dangerous to create them and suggest flashing them
externally.

That's exactly why the x230-flash build target is there: To
have a self-contained 4M image and enable easy unlocking of the 8M image
using the original data.

the heads-wiki project is updated accordingly.

Closes #307
Closes #302

[osresearch]

This needs to be fixed as part of #307 - the problem with the x230-flash image is that it doesn't unlock the IFD or clean the ME, leading to issues with reflashing the entire ROM with software.

[merge]

Right. That's why I did linuxboot/heads-wiki@1e8eec5 in order to resolve this issue. It's a documentation thing and all not that complicated: Use a 4M coreboot build for hardware flashing and unlock+flash back your 8M. From that point on you're good to go. (actually because of this confusion I created the "Skulls" project). Would such Skulls-style helper scripts fit anywhere inside of Heads too?

[tlaurion]

@merge : What is the beneficial gain in merging skull to heads, as opposed to minimizing x230-flash dependencies ?

[merge]

@tlaurion there is none. It's just about "a 4M coreboot build". Who provides it and what build exactly that will be, doesn't matter IMO. For Heads it may just be unwanted complexity to have 2 configs/builds for these laptops.

Also, "merging skulls to heads" doesn't make sense. If Heads wants to maintain such a 4M-build itself, we can just think about adding similar helper scripts for external flashing. That's all.

[merge]

We need a plan here :) we don't even know what to do yet

• First decision to make: we should agree that generating the 4M and 8M images of the x230 board is wrong in any case. We'll never be able to safely generate a flashable thing of 12M. And there's no point in having the splits other than flashing externally, which is always wrong.
  Also, flashing externally is only done the first time. And that's what the x230-flash board is for, which makes the x230 4M/8M split even more misleading. But then, x230-flash is not sufficient. At least touching the other chip's IFD is necessary.

• So, second decision to make: Do we want to support "bootstrapping" explicitely inside of Heads?

  • If so, let's add scripts that unlock the IFD on the one chip and flash x230-flash on the other, and guide users through all of it.
  • If not, drop x230-flash completely and simply add "unlocked IFD" to the requirements and add a script or (even better?) live-USB-image that flashes x230 from outside of Heads, which makes "bootstrapping" quite neat.

thoughts?

[tlaurion]

@merge I completely agree with your last comment. Checked what you are doing with skulls, and it seems completely right.

So basically, ifd tool is what is missing into x230-flash if I get it right?

[merge]

@tlaurion ifdtool is what's missing, yes. but not "into x230-flash", but applied to the 8M chip, just like documented in the Skulls project. (read, run "unlock", write).