Files
system76-coreboot/Documentation/mainboard/up/squared/index.md
Nicholas Chin 35599f9a66 Docs: Replace Recommonmark with MyST Parser
Recommonmark has been deprecated since 2021 [1] and the last release was
over 3 years ago [2]. As per their announcement, Markedly Structured
Text (MyST) Parser [3] is the recommended replacement.

For the most part, the existing documentation is compatible with MyST,
as both parsers are built around the CommonMark flavor of Markdown. The
main difference that affects coreboot is how the Sphinx toctree is
generated. Recommonmark has a feature called auto_toc_tree, which
converts single level lists of references into a toctree:

* [Part 1: Starting from scratch](part1.md)
* [Part 2: Submitting a patch to coreboot.org](part2.md)
* [Part 3: Writing unit tests](part3.md)
* [Managing local additions](managing_local_additions.md)
* [Flashing firmware](flashing_firmware/index.md)

MyST Parser does not provide a replacement for this feature, meaning the
toctree must be defined manually. This is done using MyST's syntax for
Sphinx directives:

```{toctree}
:maxdepth: 1

Part 1: Starting from scratch <part1.md>
Part 2: Submitting a patch to coreboot.org <part2.md>
Part 3: Writing unit tests <part3.md>
Managing local additions <managing_local_additions.md>
Flashing firmware <flashing_firmware/index.md>
```

Internally, auto_toc_tree essentially converts lists of references into
the Sphinx toctree structure that the MyST syntax above more directly
represents.

The toctrees were converted to the MyST syntax using the following
command and Python script:

`find ./ -iname "*.md" | xargs -n 1 python conv_toctree.py`

```
import re
import sys

in_list = False
f = open(sys.argv[1])
lines = f.readlines()
f.close()

with open(sys.argv[1], "w") as f:
    for line in lines:
        match = re.match(r"^[-*+] \[(.*)\]\((.*)\)$", line)
        if match is not None:
            if not in_list:
                in_list = True
                f.write("```{toctree}\n")
                f.write(":maxdepth: 1\n\n")
            f.write(match.group(1) + " <" + match.group(2) + ">\n")
        else:
            if in_list:
                f.write("```\n")
            f.write(line)
            in_list = False

    if in_list:
        f.write("```\n")
```

While this does add a little more work for creating the toctree, this
does give more control over exactly what goes into the toctree. For
instance, lists of links to external resources currently end up in the
toctree, but we may want to limit it to pages within coreboot.

This change does break rendering and navigation of the documentation in
applications that can render Markdown, such as Okular, Gitiles, or the
GitHub mirror. Assuming the docs are mainly intended to be viewed after
being rendered to doc.coreboot.org, this is probably not an issue in
practice.

Another difference is that MyST natively supports Markdown tables,
whereas with Recommonmark, tables had to be written in embedded rST [4].
However, MyST also supports embedded rST, so the existing tables can be
easily converted as the syntax is nearly identical.

These were converted using
`find ./ -iname "*.md" | xargs -n 1 sed -i "s/eval_rst/{eval-rst}/"`

Makefile.sphinx and conf.py were regenerated from scratch by running
`sphinx-quickstart` using the updated version of Sphinx, which removes a
lot of old commented out boilerplate. Any relevant changes coreboot had
made on top of the previous autogenerated versions of these files were
ported over to the newly generated file.

From some initial testing the generated webpages appear and function
identically to the existing documentation built with Recommonmark.

TEST: `make -C util/docker docker-build-docs` builds the documentation
successfully and the generated output renders properly when viewed in
a web browser.

[1] https://github.com/readthedocs/recommonmark/issues/221
[2] https://pypi.org/project/recommonmark/
[3] https://myst-parser.readthedocs.io/en/latest/
[4] https://doc.coreboot.org/getting_started/writing_documentation.html

Change-Id: I0837c1722fa56d25c9441ea218e943d8f3d9b804
Signed-off-by: Nicholas Chin <nic.c3.14@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73158
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2024-03-21 16:11:56 +00:00

4.7 KiB

Squared

Overview

Top

Bottom

  • Legend
    • BLUE: UART0 / USB connector
    • GREEN: UART1 / GPIO header
    • RED: SPI header
    • YELLOW: Indicates pin 1

Mainboard components

Platform

+------------------+----------------------------------+
| CPU              | Intel Atom, Celeron, Pentium     |
+------------------+----------------------------------+
| PCH              | Intel Apollo Lake                |
+------------------+----------------------------------+
| EC / Super IO    | N/A                              |
+------------------+----------------------------------+
| Coprocessor      | Intel TXE 3.0                    |
+------------------+----------------------------------+

Flash chip

+---------------------+------------+
| Type                | Value      |
+=====================+============+
| Socketed flash      | no         |
+---------------------+------------+
| Vendor              | Winbond    |
+---------------------+------------+
| Model               | W25Q128FW  |
+---------------------+------------+
| Voltage             | 1.8V       |
+---------------------+------------+
| Size                | 16 MiB     |
+---------------------+------------+
| Package             | SOIC-8     |
+---------------------+------------+
| Write protection    | No         |
+---------------------+------------+
| Internal flashing   | No         |
+---------------------+------------+
| In circuit flashing | Yes        |
+---------------------+------------+

Debugging

UART0 (CN16)

This connector is located on the bottom side (see here).

UART1 (GPIO header)

The GPIO header is located on the bottom side (see here).

Building and flashing coreboot

Using the SPI header

The SPI header is located on the bottom side (see here).

Preparations

In order to build coreboot, it's necessary to extract some files from the vendor firmware. Make sure that you have a fully working dump.

[upsquared]$ ls
firmware_vendor.rom
[upsquared]$ mkdir extracted && cd extracted
[extracted]$ ifdtool -x ../firmware_vendor.rom
File ../firmware_vendor.rom is 16777216 bytes
Peculiar firmware descriptor, assuming Ibex Peak compatibility.
  Flash Region 0 (Flash Descriptor): 00000000 - 00000fff
  Flash Region 1 (BIOS): 00001000 - 00efefff
  Flash Region 2 (Intel ME): 07fff000 - 00000fff (unused)
  Flash Region 3 (GbE): 07fff000 - 00000fff (unused)
  Flash Region 4 (Platform Data): 07fff000 - 00000fff (unused)
  Flash Region 5 (Reserved): 00eff000 - 00ffefff
  Flash Region 6 (Reserved): 07fff000 - 00000fff (unused)
  Flash Region 7 (Reserved): 07fff000 - 00000fff (unused)
  Flash Region 8 (EC): 07fff000 - 00000fff (unused)
flashregion_0_flashdescriptor.bin
flashregion_1_bios.bin
flashregion_5_reserved.bin

Clean up

[coreboot]$ make distclean

Configuring

[coreboot]$ touch .config
[coreboot]$ ./util/scripts/config --enable VENDOR_UP
[coreboot]$ ./util/scripts/config --enable BOARD_UP_SQUARED
[coreboot]$ ./util/scripts/config --enable NEED_IFWI
[coreboot]$ ./util/scripts/config --enable HAVE_IFD_BIN
[coreboot]$ ./util/scripts/config --set-str IFWI_FILE_NAME "<flashregion_1_bios.bin>"
[coreboot]$ ./util/scripts/config --set-str IFD_BIN_PATH "<flashregion_0_flashdescriptor.bin>"
[coreboot]$ make olddefconfig

Building

[coreboot]$ make

Now you should have a working and ready to use coreboot build at build/coreboot.rom.

Flashing

[coreboot]$ flashrom -p <your_programmer> -w build/coreboot.rom

Board status

Working

  • bootblock, romstage, ramstage
  • Serial console UART0, UART1
  • SPI flash console
  • iGPU init with libgfxinit
  • LAN1, LAN2
  • USB2, USB3
  • HDMI, DisplayPort
  • eMMC
  • flashing with flashrom externally

Work in progress

  • Documentation
  • ACPI

Not working / Known issues

  • Generally SeaBIOS works, but it can't find the CBFS region and therefore it can't load seavgabios. This is because of changes at the Apollolake platform.

Untested

  • GPIO pin header
  • 60 pin EXHAT
  • Camera interface
    • MIPI-CSI2 2-lane (2MP)
    • MIPI-CSI2 4-lane (8MP)
  • SATA3
  • USB3 OTG
  • embedded DisplayPort
  • M.2 slot
  • mini PCIe
  • flashing with flashrom internally using Linux