[GSOC] Panic Room, week #1

Who are you?

Hello everyone, I’m Antonello Dettori (avengerf12 on IRC) and I’m the student currently working on improving SerialICE.

What are you working on?

I’m glad you asked.

As I said just a bunch of lines before I’m working on SerialICE, which is one of the main tools used in reverse engineering an OEM BIOS and therefore in understanding the initialisation process that coreboot will have to perform in order to properly run on a target.

The original idea of my proposal was to work towards:

  • Incorporating the functionality of SerialICE into coreboot.
  • Allowing for a way to flash a coreboot-running target without a working OS environment.

The situation has changed a bit in the few months after the proposal was written and part of the goals have already been worked on by some of the wonderful contributors in the coreboot community.
I still have plenty of work to do and my mentors already pointed out some of the areas of the project with which I could spend my time.

How was your first week?

Oh boy, you had to go there, didn’t you?

I’ve been kind of a late bloomer regarding this project since only from this week I came to truly appreciate all of the work that goes into making coreboot and SerialICE tick.
I’m therefore still knee-deep in the learning process, but don’t worry, progress is being made on this front.
Unfortunately, this also means that I don’t have any actual code to reach my goals yet.

What will you do during the next week?

I will, hopefully, manage to wrap up my learning “session” with SerialICE and get to finally write some actual (possibly useful) code.
In particular I hope to fix the problem regarding the conflicts in managing the cache and its related registers that occur when coreboot initialises the target but SerialICE is used as the romstage.

That’s pretty much it  for now, see you next week!

[GSoC] Better RISC-V support, week #1

Hi, I’m Jonathan Neuschäfer (jn__ on IRC) and my GSoC project for this year is to improve coreboot’s support for RISC-V platforms. RISC-V is a new instruction set architecture (ISA) that can be implemented without paying license fees and is relatively simple.

Coreboot has already been ported to RISC-V in 2014, and has since received a bunch of patches, but since the RISC-V Privileged ISA Specification (which defines things like interrupt handling and virtual memory) is still in flux, it has become unbootable again.

My first first goal last week was to run coreboot in SPIKE, the official RISC-V emulator, and get some console output. I checked out commit 419f1b5f3 (current master) of the riscv-tools repository and built SPIKE from there.

After I patched a few outdated instructions and worked around the fact that the RISC-V binutils port currently included in coreboot targets a newer version of the RISC-V Privileged Spec by hardcoding some Control and Status Register numbers, I finally got coreboot booting until the point where it would jump into a payload, had I specified one.

All patches can be found under the riscv topic on gerrit.

Plans for this week

This week I will update my SPIKE to a version that supports the upcoming Privileged Spec 1.9, which will be released in the next couple weeks. This has the advantage that I don’t need to patch instructions because GCC encodes them differently than SPIKE decodes them. Additionally, I’ll try to get Linux to boot in SPIKE, under coreboot.