[RFC] remove SD-card support, absent from Zephyr

[josuah]

This is an illustration around which discuss for a fix:

Zephyr on LiteX VecRiscv did not work out of the box for me.

This patch is a fix for this error:

$ xargs <overlay.config west build -p -b litex_vexriscv zephyr/samples/subsys/shell/shell_module -- -DDTC_OVERLAY_FILE="$PWD/overlay.dts"
[...]
-- Found devicetree overlay: /home/zephyr/overlay.dts
devicetree error: /home/zephyr/overlay.dts:49 (column 1): parse error: undefined node label 'sdcard_block2mem'
-- In: /home/zephyr/build/zephyr, command: /home/zephyr/.venv/bin/python3.11;/home/zephyr/zephyr/scripts/dts/gen_defines.py;--dts;/home/zephyr/build/zephyr/zephyr.dts.pre;--dtc-flags;'';--bindings-dirs;/home/zephyr/zephyr/dts/bindings;--header-out;/home/zephyr/build/zephyr/include/generated/devicetree_generated.h.new;--dts-out;/home/zephyr/build/zephyr/zephyr.dts.new;--edt-pickle-out;/home/zephyr/build/zephyr/edt.pickle;--vendor-prefixes;/home/zephyr/zephyr/dts/bindings/vendor-prefixes.txt
CMake Error at /home/zephyr/zephyr/cmake/modules/dts.cmake:276 (message):
  gen_defines.py failed with return code: 1
Call Stack (most recent call first):
  /home/zephyr/zephyr/cmake/modules/zephyr_default.cmake:115 (include)
  /home/zephyr/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:66 (include)
  /home/zephyr/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:92 (include_boilerplate)
  CMakeLists.txt:4 (find_package)
-- Configuring incomplete, errors occurred!
FATAL ERROR: command exited with status 1: /usr/bin/cmake -DWEST_PYTHON=/home/zephyr/.venv/bin/python3.11 -B/home/zephyr/build -GNinja -DBOARD=litex_vexriscv -DDTC_OVERLAY_FILE=/home/zephyr/overlay.dts -DCONFIG_UART_LITEUART=y -DCONFIG_LITEX_TIMER=y -DCONFIG_ETH_LITEETH=n -DCONFIG_SPI_LITESPI=n -DCONFIG_SD_LITESD=n -DCONFIG_SD_LITESD=n -DCONFIG_SD_LITESD=n -DCONFIG_SD_LITESD=n -DCONFIG_SD_LITESD=n -DCONFIG_I2C_LITEX=n -DCONFIG_I2S_LITEX=n -DCONFIG_I2S_LITEX=n -DCONFIG_CLOCK_CONTROL_LITEX=n -DCONFIG_LITEX_CSR_DATA_WIDTH=32 -S/home/zephyr/zephyr/samples/subsys/shell/shell_module
$

What I cannot understand is why would there be SD-Card support in zephyr-on-litex-vexriscv if there is no support on upstream zephyr?

https://github.com/search?q=repo%3Azephyrproject-rtos%2Fzephyr+litesd&type=code

Did I miss something?

[enjoy-digital]

@AndrewD, @rtucker85: I think adding this was part of one of you patches, do you have more info to provide to @josuah on this?

[rtucker85]

@enjoy-digital Its been a while, and we never continued our development with Zephyr but ill be sure to take a look to refresh myself and provide more information shortly.

[enjoy-digital]

@rtucker85: Great, thanks!

[josuah]

A fix would be to allow partially working devices to not generate any configuration, rather than generate a =n.

This would allow things to be merged on LiteX side first, still have everything working for everyone, and then only merge things upstream on Zephyr side.

I am therefore closing this, but feel free to reopen if you consider that the WIP SD card support should be removed from both Zephyr and Zephry-on-LiteX-VexRiscv.