From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Graf Date: Tue, 2 Feb 2016 03:45:13 +0100 Subject: [U-Boot] [PATCH 15/16] efi_loader: Add README section in README.efi In-Reply-To: <1454381114-22547-1-git-send-email-agraf@suse.de> References: <1454381114-22547-1-git-send-email-agraf@suse.de> Message-ID: <1454381114-22547-16-git-send-email-agraf@suse.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de To preserve all cover letter knowledge of the status on UEFI payload support, let's add some sections to README.efi. Signed-off-by: Alexander Graf --- doc/README.efi | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 68 insertions(+), 1 deletion(-) diff --git a/doc/README.efi b/doc/README.efi index 23a3cdd..5834bcc 100644 --- a/doc/README.efi +++ b/doc/README.efi @@ -4,6 +4,27 @@ # SPDX-License-Identifier: GPL-2.0+ # +=========== Table of Contents =========== + + 1 U-Boot on EFI + 1.1 In God's Name, Why? + 1.2 Status + 1.3 Build Instructions + 1.4 Trying it out + 1.5 Inner workings + 1.6 EFI Application + 1.7 EFI Payload + 1.8 Tables + 1.9 Interrupts + 1.10 32/64-bit + 1.11 Future work + 1.12 Where is the code? + + 2 EFI on U-Boot + 2.1 In God's Name, Why? + 2.2 Status + 1.3 Future work + U-Boot on EFI ============= This document provides information about U-Boot running on top of EFI, either @@ -234,7 +255,6 @@ board/efi/efi-x86/efi.c common/cmd_efi.c the 'efi' command - -- Ben Stoltz, Simon Glass Google, Inc @@ -242,3 +262,50 @@ July 2015 [1] http://www.qemu.org [2] http://www.tianocore.org/ovmf/ + +------------------------------------------------------------------------------- + +EFI on U-Boot +============= + +In addition to support for running U-Boot as a UEFI application, U-Boot itself +can also expose the UEFI interfaces and thus allow UEFI payloads to run under +it. + +In God's Name, Why? +------------------- + +With this support in place, you can run any UEFI payload (such as the Linux +kernel, grub2 or gummiboot) on U-Boot. This dramatically simplifies boot loader +configuration, as U-Boot based systems now look and feel (almost) the same way +as TianoCore based systems. + +Status +------ + +I am successfully able to run grub2 and Linux EFI binaries with this code on +ARMv7 as well as AArch64 systems. + +When enabled, the resulting U-Boot binary only grows by ~10kb, so it's very +light weight. + +All storage devices are directly accessible from the uEFI payload + +Removable media booting (search for /efi/boot/boota{a64,arm}.efi) is supported. + +Simple use cases like "Plug this SD card into my ARM device and it just +boots into grub which boots into Linux", work very well. + +Future work +----------- + +Of course, there are still a few things one could do on top: + + - Improve disk media detection (don't scan, use what information we +have) + - Add EFI variable support using NVRAM + - Add GFX support + - Make EFI Shell work + - Network device support + - Support for payload exit + - Payload Watchdog support -- 2.6.2