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| -rw-r--r-- | doc/README.efi | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/doc/README.efi b/doc/README.efi index 7c95579442..23a3cdd57a 100644 --- a/doc/README.efi +++ b/doc/README.efi @@ -47,23 +47,25 @@ machine. You can use devices, boot a kernel, etc. Build Instructions ------------------ First choose a board that has EFI support and obtain an EFI implementation -for that board. It will be either 32-bit or 64-bit. +for that board. It will be either 32-bit or 64-bit. Alternatively, you can +opt for using QEMU [1] and the OVMF [2], as detailed below. -To build U-Boot as an EFI application (32-bit EFI required), enable -CONFIG_EFI and CONFIG_EFI_APP. The efi-x86 config is set up for this. +To build U-Boot as an EFI application (32-bit EFI required), enable CONFIG_EFI +and CONFIG_EFI_APP. The efi-x86 config (efi-x86_defconfig) is set up for this. +Just build U-Boot as normal, e.g. -To build U-Boot as an EFI payload (32-bit or 64-bit EFI can be used), adjust -an existing config to enable CONFIG_EFI, CONFIG_EFI_STUB and either -CONFIG_EFI_STUB_32BIT or CONFIG_EFI_STUB_64BIT. + make efi-x86_defconfig + make -Then build U-Boot as normal, e.g. +To build U-Boot as an EFI payload (32-bit or 64-bit EFI can be used), adjust an +existing config (like qemu-x86_defconfig) to enable CONFIG_EFI, CONFIG_EFI_STUB +and either CONFIG_EFI_STUB_32BIT or CONFIG_EFI_STUB_64BIT. All of these are +boolean Kconfig options. Then build U-Boot as normal, e.g. make qemu-x86_defconfig - make menuconfig (or make xconfig if you prefer) - # change the settings as above make -You will end up with one of these files: +You will end up with one of these files depending on what you build for: u-boot-app.efi - U-Boot EFI application u-boot-payload.efi - U-Boot EFI payload application @@ -71,8 +73,9 @@ You will end up with one of these files: Trying it out ------------- -Qemu is an emulator and it can emulate an x86 machine. You can run the -payload with something like this: +QEMU is an emulator and it can emulate an x86 machine. Please make sure your +QEMU version is 2.3.0 or above to test this. You can run the payload with +something like this: mkdir /tmp/efi cp /path/to/u-boot*.efi /tmp/efi @@ -80,7 +83,8 @@ payload with something like this: Add -nographic if you want to use the terminal for output. Once it starts type 'fs0:u-boot-payload.efi' to run the payload or 'fs0:u-boot-app.efi' to -run the application. 'bios.bin' is the EFI 'BIOS'. +run the application. 'bios.bin' is the EFI 'BIOS'. Check [2] to obtain a +prebuilt EFI BIOS for QEMU or you can build one from source as well. To try it on real hardware, put u-boot-app.efi on a suitable boot medium, such as a USB stick. Then you can type something like this to start it: @@ -235,3 +239,6 @@ common/cmd_efi.c Ben Stoltz, Simon Glass Google, Inc July 2015 + +[1] http://www.qemu.org +[2] http://www.tianocore.org/ovmf/ |
