IMPORTANT Information related to the gnu-efi package
+ and x86_64 efi support
----------------------------------------------------
August 2003
Note that X.y don't need to match for both packages. However elilo-3.x requires at
least gnu-efi >= 3.0. When using a version of gcc >3.0 you MUST use at least gnu-efi-3.0a.
+Note that EFI support for x86_64 has been added as a patch to gnu-efi-3.0c.
+
+For x86_64, see the important notes under x86_64.
+
IMPORTANT NOTE FOR IA-32:
-------------------------
For IA-32, the Redhat 8.0 toolchain is known to produce
The gnu-efi package can be downloaded from:
ftp://ftp.hpl.hp.com/pub/linux-ia64/gnu-efi-X.y.tar.gz
+
+IMPORTANT NOTE FOR x86_64:
+-------------------------
+
+ EFI x86_64 elilo support requires the following libraries:
+
+ 1. gnu-efi-3.0c library with x86_64 support.
+
+ 2. The toolchain known to produce working x86_64 efi binary are:
+
+ gcc-4.1.1 or above
+ binutils-2.17.50.0.14 with Intel64 EFI support
+
+ Implementation:
+ --------------
+ Calls to EFI services in x86_64 require a wrapper to pass the arguments
+ in the appropriate manner. This is implemented with efi wrapper.
+ For IA32 and IA64, the wrapper is a macro that merely calls the
+ EFI services directly. The elilo source has been modified to use the
+ efi wrapper implemented in gnu-efi-3.0c library.
+ elilo for x86_64 and its dependent libraries are built and the final
+ ELF image is converted into PE-COFF image using the objcopy supported
+ by binutils-2.17.50.0.14 or above with Intel64 EFI support.
+
+ On UEFI 2.0 firmware, only Graphics Output Protocol (GOP) is supported.
+ The x86_64 elilo first queries video information from GOP failing which
+ it queries for text mode support. The video information is passed to
+ Linux kernel via boot parameter. The GOP support requires
+ Linux kernel EFI framebuffer driver (kernel configuration option).