diff options
author | Simon Glass <sjg@chromium.org> | 2020-05-01 07:36:10 -0600 |
---|---|---|
committer | Bin Meng <bmeng.cn@gmail.com> | 2020-05-04 15:28:28 +0800 |
commit | 538437ed39e01b7ecfa79669982fe7db51fb2e1b (patch) | |
tree | 50ff767d8d52438b551ae11641c9d42d4274ea36 /doc/board | |
parent | 8d99d5434b1c98c832f7a1aa0a0e0c9ab4c284a1 (diff) |
x86: Add a 64-bit 'coreboot64' build
Coreboot is a first-stage bootloader mostly used on x86 devices as an
alternative to UEFI. Coreboot runs in 32-bit mode.
U-Boot currently supports booting from coreboot as a second-stage
bootloader, also in 32-bit mode. However it is useful to be able to run
U-Boot in 64-bit mode. To do this we can have a 32-bit SPL which switches
over the CPU and jumps to a 64-bit U-Boot proper.
Add a new 'coreboot64' board for running 64-bit U-Boot from coreboot. This
uses binman to create an image with a 32-bit SPL and a 64-bit U-Boot.
This allows running 64-bit EFI images on x86, for example, without needing
a native U-Boot port for a board.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Diffstat (limited to 'doc/board')
-rw-r--r-- | doc/board/coreboot/coreboot.rst | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/doc/board/coreboot/coreboot.rst b/doc/board/coreboot/coreboot.rst index fd974229eb..9c44c025a4 100644 --- a/doc/board/coreboot/coreboot.rst +++ b/doc/board/coreboot/coreboot.rst @@ -40,3 +40,13 @@ To enable video you must enable these options in coreboot: At present it seems that for Minnowboard Max, coreboot does not pass through the video information correctly (it always says the resolution is 0x0). This works correctly for link though. + +64-bit U-Boot +------------- + +In addition to the 32-bit 'coreboot' build there is a 'coreboot64' build. This +produces an image which can be booted from coreboot (32-bit). Internally it +works by using a 32-bit SPL binary to switch to 64-bit for running U-Boot. It +can be useful for running UEFI applications, for example. + +This has only been lightly tested. |