The youngest architecture addition to the mainline Linux kernel was C-Sky (arch/csky/).

I have a GX6605S board booting a downstream 4.9 kernel. It uses a proprietary GxLoader bootloader (similarities with U-Boot exist but no sources...) with uImage and gx6605s.dtb files in a FAT partition on USB stick.

I prepared a csky-elf GCC cross-toolchain and would like to try building and booting a mainline kernel on that board. This will involve writing a mainline-compatible .dts for this board that, if successful, I could contribute upstream.

Besides learning about this architecture and any commonalities and differences, I am curious whether I can use the 3 accessible GPIOs on the board for connecting any radio transceivers for testing my LoRa, FSK, etc. kernel network drivers. Too little for bit-banging SPI, I guess, and seemingly no pin-muxing to UART. Maybe some I²C sensor though?

Looking for hackers with the skills:

csky kernel

This project is part of:

Hack Week 18

Activity

  • over 5 years ago: lyan liked this project.
  • over 5 years ago: a_faerber added keyword "csky" to this project.
  • over 5 years ago: a_faerber added keyword "kernel" to this project.
  • over 5 years ago: a_faerber started this project.
  • over 5 years ago: a_faerber originated this project.

  • Comments

    • a_faerber
      over 5 years ago by a_faerber | Reply

      It was confirmed today that upstream GCC is still lacking support for ck610. So my sub-project of packaging a csky-elf abiv1 cross-compiler is dead for now.

    • a_faerber
      over 5 years ago by a_faerber | Reply

      Yesterday compiled and booted mainline and linux-next kernels (up to an error executing the init process), sending out a patch for the Device Tree I derived.

    Similar Projects

    Create DRM drivers for VESA and EFI framebuffers by tdz

    Description

    We already have simpledrm for firmware framebuffers. But the driver is originally for ARM boards, not PCs. It is already overloaded with code to support both use cases. At the same time it is missing possible features for VESA and EFI, such as palette modes or EDID support. We should have DRM drivers for VESA and EFI interfaces. The infrastructure exists already and initial drivers can be forked from simpledrm.

    Goals

    • Initially, a bare driver for VESA or EFI should be created. It can take functionality from simpledrm.
    • Then we can begin to add additional features. The boot loader can provide EDID data. With VGA hardware, VESA can support paletted modes or color management. Example code exists in vesafb.


    Modernize ocfs2 by goldwynr

    Ocfs2 has gone into a stage of neglect and disrepair. Modernize the code to generate enough interest.

    Goals: * Change the mount sequence to use fscontext * Move from using bufferhead to bio/folios * Use iomap * Run it through xfstests


    Linux on Cavium CN23XX cards by tsbogend

    Before Cavium switched to ARM64 CPUs they developed quite powerful MIPS based SOCs. The current upstream Linux kernel already supports some Octeon SOCs, but not the latest versions. Goal of this Hack Week project is to use the latest Cavium SDK to update the Linux kernel code to let it running on CN23XX network cards.


    Improve UML page fault handler by ptesarik

    Description

    Improve UML handling of segmentation faults in kernel mode. Although such page faults are generally caused by a kernel bug, it is annoying if they cause an infinite loop, or panic the kernel. More importantly, a robust implementation allows to write KUnit tests for various guard pages, preventing potential kernel self-protection regressions.

    Goals

    Convert the UML page fault handler to use oops_* helpers, go through a few review rounds and finally get my patch series merged in 6.14.

    Resources

    Wrong initial attempt: https://lore.kernel.org/lkml/20231215121431.680-1-petrtesarik@huaweicloud.com/T/


    RISC-V emulator in GLSL capable of running Linux by favogt

    Description

    There are already numerous ways to run Linux and some programs through emulation in a web browser (e.g. x86 and riscv64 on https://bellard.org/jslinux/), but none use WebGL/WebGPU to run the emulation on the GPU.

    I already made a PoC of an AArch64 (64-bit Arm) emulator in OpenCL which is unfortunately hindered by a multitude of OpenCL compiler bugs on all platforms (Intel with beignet or the new compute runtime and AMD with Mesa Clover and rusticl). With more widespread and thus less broken GLSL vs. OpenCL and the less complex implementation requirements for RV32 (especially 32bit integers instead of 64bit), that should not be a major problem anymore.

    Goals

    Write an RISC-V system emulator in GLSL that is capable of booting Linux and run some userspace programs interactively. Ideally it is small enough to work on online test platforms like Shaderoo with a custom texture that contains bootstrap code, kernel and initrd.

    Minimum:

    riscv32 without FPU (RV32 IMA) and MMU (µClinux), running Linux in M-mode and userspace in U-mode.

    Stretch goals:

    FPU support, S-Mode support with MMU, SMP. Custom web frontend with more possibilities for I/O (disk image, network?).

    Resources

    RISC-V ISA Specifications
    Shaderoo
    OpenGL 4.5 Quick Reference Card

    Result as of Hackweek 2024

    WebGL turned out to be insufficient, it only supports OpenGL ES 3.0 but imageLoad/imageStore needs ES 3.1. So we switched directions and had to write a native C++ host for the shaders.

    As of Hackweek Friday, the kernel attempts to boot and outputs messages, but panics due to missing memory regions.

    Since then, some bugs were fixed and enough hardware emulation implemented, so that now Linux boots with framebuffer support and it's possible to log in and run programs!

    The repo with a demo video is available at https://github.com/Vogtinator/risky-v