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android-review.linaro.org / kernel / lk / 82e565e232ba01b28b5dcefea0af7cdb0bbdc964
commit82e565e232ba01b28b5dcefea0af7cdb0bbdc964[log] [tgz]
authorAlex Richardson <alexrichardson@google.com>Thu Dec 09 14:40:59 2021 +0000
committerTravis Geiselbrecht <travisg@gmail.com>Thu Jun 01 17:50:50 2023 -0700
treeef527c2ac6326df272868007febbda15f6d5a2ed
parent365bb4e7a7ad8c376d5a23b06d6feac6c61c5a4d [diff]
[arm64] Allow assembling with clang

Clang does not accept this .if condition since phys_offset is a register
alias and not an absolute expression. We can keep these two instructions
here if the argument is zero since the result will be the same.
Additionally, this macro is only called once and always passes a non-zero
argument. If more calls are added in the future and avoiding these two
instructions just before a loop is really important, we could use
`.ifnc \phys_offset,0` instead, but that looks rather obscure to me.
1 file changed
tree: ef527c2ac6326df272868007febbda15f6d5a2ed
  1. .github/
  2. app/
  3. arch/
  4. dev/
  5. docs/
  6. external/
  7. kernel/
  8. lib/
  9. make/
  10. platform/
  11. project/
  12. scripts/
  13. target/
  14. tools/
  15. top/
  16. .gitignore
  17. engine.mk
  18. LICENSE
  19. lk_inc.mk.example
  20. makefile
  21. README.md
README.md

The Little Kernel Embedded Operating System

The LK kernel is an SMP-aware kernel designed for small systems ported to a variety of platforms and cpu architectures.

See https://github.com/littlekernel/lk for the latest version.

High Level Features

  • Fully-reentrant multi-threaded preemptive kernel
  • Portable to many 32 and 64 bit architectures
  • Support for wide variety of embedded and larger platforms
  • Powerful modular build system
  • Large number of utility components selectable at build time

Supported architectures

  • ARM32
    • Cortex-M class cores (armv6m - armv8m)
    • ARMv7+ Cortex-A class cores
  • ARM64
  • RISC-V 32 and 64bit bit in machine and supervisor mode
  • x86-32 and x86-64 386 up through modern cores
  • microblaze
  • MIPS
  • OpenRISC 1000

TODO

To build and test for ARM on linux

  1. install or build qemu. v2.4 and above is recommended.
  2. install gcc for embedded arm (see note 1)
  3. run scripts/do-qemuarm (from the lk directory)
  4. you should see 'welcome to lk/MP'

This will get you a interactive prompt into LK which is running in qemu arm machine 'virt' emulation. type 'help' for commands.

Note: for ubuntu x86-64: sudo apt-get install gcc-arm-none-eabi or fetch a prebuilt toolchain from https://newos.org/toolchains/x86_64-elf-10.2.0-Linux-x86_64.tar.xz