# boards/

One directory per physical target. `make boot_image TARGET=<NAME>` (repo root) maps the
name to a directory here, reads its `board.mk`, and builds the single file that goes on
that board's boot medium into `build/boards/<board>/`.

| TARGET | Directory | ISA | Boot path | Image |
|---|---|---|---|---|
| `SER5` | `ser5/` | amd64 | UEFI firmware, removable-media path | GPT + FAT32 ESP: `EFI/BOOT/BOOTX64.EFI` |
| `RASPI` | `raspi/` | aarch64 | Pi 5 EEPROM firmware, native | MBR + FAT32: `config.txt`, `kernel_2712.img`, `bcm2712-rpi-5-b.dtb` |
| `MILKV` | `milkv/` | riscv64 | SPI-flash U-Boot + OpenSBI, `bootefi` | GPT + FAT32 ESP: `EFI/BOOT/BOOTRISCV64.EFI` |
| `ZYNQ7020` | `zynq7020/` | armv7 | BootROM, `BOOT.BIN`, U-Boot | not yet: needs `kernel/src/arch/armv7` |

`board.mk` sets:

- `BOARD_DESC`: one-line description (`make boards`)
- `BOARD_ARCH`: kernel ISA (`kernel/src/arch/<arch>`)
- `BOARD_BOOT`: image recipe in `kernel/Makefile` (`uefi-esp`, `rpi-native`, ...)
- `BOARD_IMAGE`: output file name

Disk images are assembled by `scripts/mkdiskimage.sh`, which needs no root access and no loop
devices. `KERNEL_ARGS="..."` is written as `starforth.cfg` (UEFI boards) or `cmdline.txt`
(Pi 5, where the firmware copies it into `/chosen/bootargs`). `BOOT_IMAGE_SIZE_MIB` sets the
image size; the default is 128.

Hardware status: none of these images has been booted on real silicon from this build. The
SER5 image has been booted in QEMU (q35 + OVMF, from its own disk) through POST. The Pi 5
native path (`raspi/README.md`) and the JH7110 peripherals have still only been checked by
compiling.