summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSimon Glass <sjg@chromium.org>2023-09-03 18:15:51 +0300
committerHeinrich Schuchardt <heinrich.schuchardt@canonical.com>2023-09-09 07:12:47 +0300
commit063536a7810d4e760787592f1b8e0e01992fa796 (patch)
tree7b27991f412b6b72354881051bd5cfac731a0289
parent5d1fa6b6a64713072eeb001247f2a083806f2c48 (diff)
downloadu-boot-063536a7810d4e760787592f1b8e0e01992fa796.tar.xz
doc: efi: Update for the 64-bit app
The 64-bit app is supported now, so update the documentation. Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
-rw-r--r--doc/develop/uefi/u-boot_on_efi.rst26
1 files changed, 11 insertions, 15 deletions
diff --git a/doc/develop/uefi/u-boot_on_efi.rst b/doc/develop/uefi/u-boot_on_efi.rst
index 0d4927807c..245b4af1fa 100644
--- a/doc/develop/uefi/u-boot_on_efi.rst
+++ b/doc/develop/uefi/u-boot_on_efi.rst
@@ -31,14 +31,12 @@ Only x86 is supported at present. If you are using EFI on another architecture
you may want to reconsider. However, much of the code is generic so could be
ported.
-U-Boot supports running as an EFI application for 32-bit EFI only. This is
-not very useful since only a serial port is provided. You can look around at
-memory and type 'help' but that is about it.
+U-Boot supports running as an EFI application for both 32- and 64-bit EFI.
-More usefully, U-Boot supports building itself as a payload for either 32-bit
-or 64-bit EFI. U-Boot is packaged up and loaded in its entirety by EFI. Once
-started, U-Boot changes to 32-bit mode (currently) and takes over the
-machine. You can use devices, boot a kernel, etc.
+U-Boot supports building itself as a payload for either 32-bit or 64-bit EFI.
+U-Boot is packaged up and loaded in its entirety by EFI. Once started, U-Boot
+changes to 32-bit mode (currently) and takes over the machine. You can use
+devices, boot a kernel, etc.
Build Instructions
@@ -47,9 +45,9 @@ 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. 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_app config (efi-x86_app32_defconfig) is set up
-for this. Just build U-Boot as normal, e.g.::
+To build U-Boot as an EFI application, enable CONFIG_EFI and CONFIG_EFI_APP.
+The efi-x86_app32 and efi-x86_app64 configs are set up for this. Just build
+U-Boot as normal, e.g.::
make efi-x86_app32_defconfig
make
@@ -189,9 +187,9 @@ interrupts disabled at present.
32/64-bit
~~~~~~~~~
-While the EFI application can in principle be built as either 32- or 64-bit,
-only 32-bit is currently supported. This means that the application can only
-be used with 32-bit EFI.
+While the EFI application can be built as either 32- or 64-bit, you need to be
+careful to build the correct one so that your UEFI firmware can start it. Most
+UEFI images are 64-bit at present.
The payload stub can be build as either 32- or 64-bits. Only a small amount
of code is built this way (see the extra- line in lib/efi/Makefile).
@@ -345,8 +343,6 @@ This work could be extended in a number of ways:
- Add ARM support
-- Add 64-bit application support (in progress)
-
- Figure out how to solve the interrupt problem
- Add more drivers to the application side (e.g.USB, environment access).