diff options
| -rw-r--r-- | README.md | 19 | ||||
| -rwxr-xr-x | arch/riscv64/conf/init | bin | 3600 -> 3648 bytes | |||
| -rw-r--r-- | arch/riscv64/conf/init.c | 7 | ||||
| -rw-r--r-- | arch/riscv64/conf/initrd | bin | 4096 -> 4096 bytes | |||
| -rw-r--r-- | docs/boot.md | 10 | ||||
| -rw-r--r-- | docs/visionfive2.md | 60 |
6 files changed, 76 insertions, 20 deletions
@@ -1,9 +1,10 @@ -# `kmi` +# kmi -`kmi` is a ***K***ernel with ***MI***grating threads I've been writing as a hobby project. +`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 +Currently the kernel has been run on `qemu` with the `virt` board and on a +StarFive VisionFive2 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 @@ -40,17 +41,7 @@ runtime when undefined behavior is detected. Only available with `RELEASE=0`. booting the kernel through u-boot's `go` command. This would in theory allow using essentially any precompiled u-boot as a bootloader, but requires some extra effort by the user to manage loading different parts to where they should -go. I should probably come up with a full example, but approximately: - -1. Load `kmi.bin` to address `A` -2. Load `initrd` to address `B` -3. Load FDT to address `C` (either provided by u-boot or a separate file) -4. Add `initrd` to FDT's `chosen` node -5. Boot with `go ${A} ${C}`. - -Note that u-boot likes to skip the `0x` prefix for -hexadecimal values, which can confuse my string converter. -Check that the strings you pass to `go` have their correct prefixes. +go. See `docs/visionfive2.md` for an example. + `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). diff --git a/arch/riscv64/conf/init b/arch/riscv64/conf/init Binary files differindex c77c048..76de753 100755 --- a/arch/riscv64/conf/init +++ b/arch/riscv64/conf/init diff --git a/arch/riscv64/conf/init.c b/arch/riscv64/conf/init.c index b2f4024..8177992 100644 --- a/arch/riscv64/conf/init.c +++ b/arch/riscv64/conf/init.c @@ -256,6 +256,8 @@ void callback(long status, long tid, long d0, long d1, long d2, long d3) #define csr_read(csr, \ res) __asm__ volatile ("csrr %0, " csr : "=r" (res) :: "memory") +#define CSR_CYCLE "0xc00" + void _start() { sys_noop(); @@ -264,17 +266,20 @@ void _start() uint64_t second = sys_timebase(); print_value("Timebase", second); - uint64_t n = 0, i, start; + uint64_t n = 0, i, start, cn, cstart, cend; start = i = sys_ticks(); print_value("Start ticks", start); + csr_read(CSR_CYCLE, cstart); while (i < start + second) { i = sys_ticks(); n++; } + csr_read(CSR_CYCLE, cend); print_value("End ticks", i); print_value("Syscalls per second", n); + print_value("Executed cycles per second", cend - cstart); puts("Setting callback..."); sys_ipc_server(callback); diff --git a/arch/riscv64/conf/initrd b/arch/riscv64/conf/initrd Binary files differindex fb6f525..e4d76a2 100644 --- a/arch/riscv64/conf/initrd +++ b/arch/riscv64/conf/initrd diff --git a/docs/boot.md b/docs/boot.md index 2131d93..f79f475 100644 --- a/docs/boot.md +++ b/docs/boot.md @@ -1,11 +1,11 @@ I need to figure out how to write MarkDown files, but the general procedure of a boot is that we -1) Assume we start of in real memory mode, i.e. no MMU active. +1. Assume we start of in real memory mode, i.e. no MMU active. -2) arch/whatever/init/init.c kickstarts us into virtual memory with a direct -mapping, with offset VM_DMAP aliasing to physical address 0. +2. arch/whatever/init/init.c kickstarts us into virtual memory with a direct +mapping, with offset `VM_DMAP` aliasing to physical address 0. -3) The kernel proper is moved to its correct location in this direct mapping. +3. The kernel proper is moved to its correct location in this direct mapping. -4) The kernel proper is jumped to, after which the kernel does whatever. +4. The kernel proper is jumped to, after which the kernel does whatever. diff --git a/docs/visionfive2.md b/docs/visionfive2.md new file mode 100644 index 0000000..51067f1 --- /dev/null +++ b/docs/visionfive2.md @@ -0,0 +1,60 @@ +# StarFive VisionFive2 + +## Booting + +Ideally I would fork StarFive's u-boot fork and add 'native' support for my +kernel, but it turns out that their fork is at the time of writing borked and +I wasn't able to get anything to boot with it. As such, we'll use their prebuilt +bootloader and boot in a more generic way. + +The following is how to boot with an SD card. The board seems to support +serial and ethernet booting, but I haven't looked into how they work. + +1. Build `kmi` with `GENERIC_UBOOT=1`. + +2. Create three partitions on an SD card of your choice: +``` +sudo sgdisk --clean \ + --new=1:4096:8191 --change-name=1:"spl" --typecode=1:2E54B353-1271-4842-806F-E436D6AF6985 \ + --new=2:8192:16383 --change-name=2:"uboot" --typecode=2:5B193300-FC78-40CD-8002-E86C45580B47 \ + --new=3:16384:0 --change-name=3:"data" \ + /dev/sdX +``` + +3. Prepare partitions with data: +``` +sudo dd if=u-boot-spl.bin.normal.out of=/dev/sdX1 +sudo dd if=visionfive2_fw_payload.img of=/dev/sdX2 +sudo mkfs.ext2 /dev/sdX3 +``` + +4. Copy `kmi.bin` and `initrd` to SD card: +``` +sudo mount /dev/sdX3 /mnt/sdcard # or wherever +sudo cp kmi.bin arch/riscv64/conf/initrd /mnt/sdcard +sudo umount /mnt/sdcar +sync +``` + +With the SD card ready to go, reset the device and manually run these commands: + +1. `fdt move 0xcce379d0 ${fdt_addr_r}` +2. `load mmc 1:3 0x47000000 kmi.bin` +3. `load mmc 1:3 0x48000000 initrd` +4. `fdt chosen 0x48000000 0x48001000` +5. `go 0x47000000 ${fdt_addr_r}` + +These commands are pretty hard coded and might not work in the future, in which +case I should come and update them. + +Other things to note: + +U-boot likes to skip the `0x` prefix for +hexadecimal values, which can confuse my string converter. +Check that the strings you pass to `go` have their correct prefixes. + +Depending on the u-boot version, the `fdt chosen` command either takes +the end address or the size of the `initrd`. + +It should be possible to add the above commands to a script to run +automatically, though I haven't personally done this yet. |