From: Simon Glass Date: Wed, 29 Dec 2021 18:57:38 +0000 (-0700) Subject: x86: Allow booting a kernel from the EFI app X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=6e7ad4a45f6e2b036fc56942293b8471ece3341d;p=u-boot.git x86: Allow booting a kernel from the EFI app At present this is disabled, but it should work so long as the kernel does not need EFI services. Enable it and add a note about remaining work. Signed-off-by: Simon Glass --- diff --git a/arch/x86/lib/bootm.c b/arch/x86/lib/bootm.c index 667e5e689e..57cba5c65d 100644 --- a/arch/x86/lib/bootm.c +++ b/arch/x86/lib/bootm.c @@ -179,10 +179,14 @@ int boot_linux_kernel(ulong setup_base, ulong load_address, bool image_64bit) * U-Boot is setting them up that way for itself in * arch/i386/cpu/cpu.c. * - * Note that we cannot currently boot a kernel while running as - * an EFI application. Please use the payload option for that. + * Note: this is incomplete for EFI kernels! + * + * This can boot a kernel while running as an EFI application, + * but if the kernel requires EFI support then that support needs + * to be enabled first (see EFI_LOADER). Also the EFI information + * must enabled with setup_efi_info(). See setup_zimage() for + * how this is done with the stub. */ -#ifndef CONFIG_EFI_APP __asm__ __volatile__ ( "movl $0, %%ebp\n" "cli\n" @@ -191,7 +195,6 @@ int boot_linux_kernel(ulong setup_base, ulong load_address, bool image_64bit) [boot_params] "S"(setup_base), "b"(0), "D"(0) ); -#endif } /* We can't get to here */ diff --git a/doc/develop/uefi/u-boot_on_efi.rst b/doc/develop/uefi/u-boot_on_efi.rst index 8f81b79907..acad6397e8 100644 --- a/doc/develop/uefi/u-boot_on_efi.rst +++ b/doc/develop/uefi/u-boot_on_efi.rst @@ -269,7 +269,7 @@ This work could be extended in a number of ways: - Avoid turning off boot services in the stub. Instead allow U-Boot to make use of boot services in case it wants to. It is unclear what it might want - though. + though. It is better to use the app. Where is the code? ------------------