u-boot/arch/x86
Graeme Russ 9e6c572ff0 x86: Use fs for global data
Use the base address of the 'F' segment as a pointer to the global data
structure. By adding the linear address (i.e. the 'D' segment address) as
the first word of the global data structure, the address of the global data
relative to the 'D' segment can be found simply, for example, by:

	fs movl 0, %eax

This makes the gd 'pointer' writable prior to relocation (by reloading the
Global Desctriptor Table) which brings x86 into line with all other arches

NOTE: Writing to the gd 'pointer' is expensive (but we only do it
twice) but using it to access global data members (read and write) is
still fairly cheap

--
Changes for v2:
 - Rebased against changes made to patch #3
 - Removed extra indent
 - Tweaked commit message
2012-01-04 22:17:24 +11:00
..
cpu x86: Use fs for global data 2012-01-04 22:17:24 +11:00
include/asm x86: Use fs for global data 2012-01-04 22:17:24 +11:00
lib x86: Use fs for global data 2012-01-04 22:17:24 +11:00
config.mk x86: Wrap small helper functions from libgcc to avoid an ABI mismatch 2011-11-29 21:31:24 +11:00