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Damn Broadcom and their damned incorrect assumptions about x86 memory 

allocation.
pull/1/head
Michael Brown 2007-01-13 01:48:12 +00:00
parent 341c0b9cfb
commit 86171c53f4
1 changed files with 24 additions and 3 deletions
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27
src/arch/i386/prefix/libprefix.S
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@ -17,6 +17,26 @@
* *
*/ */
/**
* High memory temporary load address
*
* Temporary buffer into which to copy (or decompress) our runtime
* image, prior to calling get_memmap() and relocate(). We don't
* actually leave anything here once install() has returned.
*
* We use the start of an even megabyte so that we don't have to worry
* about the current state of the A20 line.
*
* We use 4MB rather than 2MB because there is at least one commercial
* PXE ROM ("Broadcom UNDI, PXE-2.1 (build 082) v2.0.4") which stores
* data required by the UNDI ROM loader (yes, the ROM loader; that's
* the component which should be impossible to damage short of
* screwing with the MMU) around the 2MB mark. Sadly, this is not a
* joke.
*
*/
#define HIGHMEM_LOADPOINT ( 4 << 20 )
#define CR0_PE 1 #define CR0_PE 1
.arch i386 .arch i386
@ -345,11 +365,12 @@ install_prealloc:
movw %ax, (init_librm_vector+2) movw %ax, (init_librm_vector+2)
movw %ax, (prot_call_vector+2) movw %ax, (prot_call_vector+2)
/* Install .text and .data to 2MB mark. Use 2MB to avoid /* Install .text and .data to temporary area in high memory,
* problems with A20. * prior to reading the E820 memory map and relocating
* properly.
*/ */
call flatten_real_mode call flatten_real_mode
movl $(2<<20), %edi movl $HIGHMEM_LOADPOINT, %edi
call install_highmem call install_highmem
/* Set up initial protected-mode GDT, call relocate(). /* Set up initial protected-mode GDT, call relocate().