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| -rw-r--r-- | README.md | 52 |
1 files changed, 47 insertions, 5 deletions
@@ -1,5 +1,47 @@ -Requirements for a new arch: -+ arch/$(ARCH)/conf/init-link.S -+ arch/$(ARCH)/conf/init-kernel.S -+ arch/$(ARCH)/source.mk - -> populate KERNEL_SOURCES, INIT_SOURCES and CLEANUP if required +# `kmi` + +`kmi` is a ***K***ernel with ***MI***grating threads I've been writing as a hobby project. +To see it in action, have a look at [kmi-example](https://github.com/Kimplul/kmi-example). + +Currently the kernel only works in `qemu` with RISC-V 64 bit. There is some code for +RISC-V 32 bit support, but at the moment I'm focusing on 64 bit and 32 is less tested. + +# Building + +`riscv64-unknown-elf-` is the default toolchain looked for by the build system, but +`riscv64-linux-gnu-` will also work. Either should be available from your package manager. + +Simple build with default configuration: ++ `make` + +This results in `kmi.bin`, which is the bootloader and the payload kernel. +Currently the kernel expects to be loaded into a specific address, allowing arbitrary boot +locations is on my TODO list. The load address depends on the configured RAM base address, +see `arch/riscv64/conf/kmi.its` and `PM_KERN_BASE`. Dynamically detecting RAM base is also TODO. + +Useful `make` flags and targets: + ++ `docs`: Generate HTML documentation with doxygen. Currently mostly documents API stuff, +but my intention is to include higher level documentation as well. +Open `docs/output/html/index.html` in your favorite web browser. + ++ `RELEASE=<0/1>`: Enable optimizations when set to `1`. Default is `0`. +Note that with `RELEASE=1` the built in serial driver is disabled, as eventually +I'd like to provide it as a separate userspace driver. At the moment only NS16550A and +compatible serial devices are supported. + ++ `LLVM=<0/1>`: Use LLVM toolchain when set to `1`. Default is `0`. +Note that due to some bugs and missing features in LLVM RISC-V support, some GNU +binutils tools are still needed, mainly `objcopy`. Also, when combined with `RELEASE`, +disables LTO as `lld` seemed to have issues with some relaxed instructions with LTO enabled. + ++ `UBSAN=<0/1>`: Enable undefined behavior sanitizer, outputs a number of warnings at runtime when +undefined behavior is detected. Only available with `RELEASE=0`. + ++ `run`: Load a test program into `qemu` and run it. Requires some outside support at the moment, +please see [kmi-example](https://github.com/Kimplul/kmi-example). This command might eventually be moved +out of this repo. + ++ `clean/clean_docs/clean_run/clean_all`: Clean compile artefacts, clean documentation artefacts, +clean run artefacts and clean all artefacts, respectively. Note that `clean_run` and `clean_all` may +need root privileges. |