Initial import

1 files changed, 42 insertions, 0 deletions

diff --git a/Documentation/x86/x86_64/uefi.txt b/Documentation/x86/x86_64/uefi.txt
new file mode 100644
index 000000000..a5e2b4fdb
--- /dev/null
+++ b/Documentation/x86/x86_64/uefi.txt
@@ -0,0 +1,42 @@
+General note on [U]EFI x86_64 support
+-------------------------------------
+
+The nomenclature EFI and UEFI are used interchangeably in this document.
+
+Although the tools below are _not_ needed for building the kernel,
+the needed bootloader support and associated tools for x86_64 platforms
+with EFI firmware and specifications are listed below.
+
+1. UEFI specification:  http://www.uefi.org
+
+2. Booting Linux kernel on UEFI x86_64 platform requires bootloader
+   support. Elilo with x86_64 support can be used.
+
+3. x86_64 platform with EFI/UEFI firmware.
+
+Mechanics:
+---------
+- Build the kernel with the following configuration.
+	CONFIG_FB_EFI=y
+	CONFIG_FRAMEBUFFER_CONSOLE=y
+  If EFI runtime services are expected, the following configuration should
+  be selected.
+	CONFIG_EFI=y
+	CONFIG_EFI_VARS=y or m		# optional
+- Create a VFAT partition on the disk
+- Copy the following to the VFAT partition:
+	elilo bootloader with x86_64 support, elilo configuration file,
+	kernel image built in first step and corresponding
+	initrd. Instructions on building elilo	and its dependencies
+	can be found in the elilo sourceforge project.
+- Boot to EFI shell and invoke elilo choosing the kernel image built
+  in first step.
+- If some or all EFI runtime services don't work, you can try following
+  kernel command line parameters to turn off some or all EFI runtime
+  services.
+	noefi		turn off all EFI runtime services
+	reboot_type=k	turn off EFI reboot runtime service
+- If the EFI memory map has additional entries not in the E820 map,
+  you can include those entries in the kernels memory map of available
+  physical RAM by using the following kernel command line parameter.
+	add_efi_memmap	include EFI memory map of available physical RAM