This series introduces the EFI_RAM_DISK_PROTOCOL implementation. The major purpose of this series is a preparation for EFI HTTP(S) boot.
Now U-Boot can download the distro installer ISO image via wget or tftpboot commands, but U-Boot can not mount the downloaded ISO image. By calling EFI_RAM_DISK_PROTOCOL->register API, user can mount the ISO image and boot the distro installer.
Note that the installation process may not proceed after the distro installer calls ExitBootServices() since there is no hand-off process for the block device of memory mapped ISO image.
The EFI_RAM_DISK_PROTOCOL was tested with the debian network installer[1] on qemu_arm64 platform. The example procedure is as follows. => tftpboot 41000000 mini.iso => efidebug disk load 41000000 $filesize
After these commands, ISO image is mounted like:
=> efidebug dh
000000007eec5910 (efiblk#0) /RamDisk(0x41000000,4974afff,3d5abd30-4175-87ce-6d64-d2ade523c4bb,0x0) Block IO
000000007eec6140 (efiblk#0:1) /RamDisk(0x41000000,4974afff,3d5abd30-4175-87ce-6d64-d2ade523c4bb,0x0)/HD(1,0x01,0,0x0,0x33800) Block IO
000000007eec62b0 (efiblk#0:2) /RamDisk(0x41000000,4974afff,3d5abd30-4175-87ce-6d64-d2ade523c4bb,0x0)/HD(2,0x01,0,0x33800,0x10000) Block IO System Partition Simple File System
=> dm tree
blk 0 [ + ] efi_blk `-- efiblk#0 partition 0 [ + ] blk_partition |-- efiblk#0:1 partition 1 [ + ] blk_partition `-- efiblk#0:2
Debian can be successfully installed with this RAM disk on QEMU.
[TODO] - udevices created in ./lib/efi_driver/efi_block_device.c::efi_bl_bind() are not removed when the efi_handle is removed. So after unload the RAM disk, udevices still exist. I plan to add a udevice removal process in ./lib/efi_driver/efi_uclass.c::efi_uc_stop(). In addition, I also plan to add unbind() callback in struct efi_driver_ops.
[1] https://deb.debian.org/debian/dists/bookworm/main/installer-arm64/current/im...
Masahisa Kojima (4): efi_loader: add RAM disk device path efi_loader: add EFI_RAM_DISK_PROTOCOL implementation cmd: efidebug: add RAM disk mount command efi_selftest: add EFI_RAM_DISK_PROTOCOL selftest
cmd/efidebug.c | 117 ++++++ include/efi_api.h | 32 ++ include/efi_loader.h | 4 + lib/efi_driver/efi_uclass.c | 7 +- lib/efi_loader/Kconfig | 6 + lib/efi_loader/Makefile | 1 + lib/efi_loader/efi_device_path_to_text.c | 14 + lib/efi_loader/efi_ram_disk.c | 334 +++++++++++++++ lib/efi_loader/efi_setup.c | 6 + lib/efi_selftest/Makefile | 1 + lib/efi_selftest/efi_selftest_ram_disk.c | 511 +++++++++++++++++++++++ lib/uuid.c | 4 + 12 files changed, 1035 insertions(+), 2 deletions(-) create mode 100644 lib/efi_loader/efi_ram_disk.c create mode 100644 lib/efi_selftest/efi_selftest_ram_disk.c
base-commit: e2e2aea5733f0d23cd9593bbefe5c803c552dcb9