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| author | Jan Beulich <jbeulich@novell.com> | 2011-08-19 09:54:26 +0100 |
|---|---|---|
| committer | Jan Beulich <jbeulich@novell.com> | 2011-08-19 09:54:26 +0100 |
| commit | bc4a68f21f43c2e37346cf5a1f37c19a53b540c2 (patch) | |
| tree | 3b4af0bd3182a264bbe3b84a65e21a606e4f43ab /xen/arch/x86/boot/head.S | |
| parent | 2f399b3bb0cae8072ed42856eac6a805728516fe (diff) | |
| download | xen-bc4a68f21f43c2e37346cf5a1f37c19a53b540c2.tar.gz xen-bc4a68f21f43c2e37346cf5a1f37c19a53b540c2.tar.bz2 xen-bc4a68f21f43c2e37346cf5a1f37c19a53b540c2.zip | |
x86: make run-time part of trampoline relocatable
In order to eliminate an initial hack in the EFI boot code (where
memory for the trampoline was just "claimed" instead of properly
allocated), the trampoline code must no longer make assumption on the
address at which it would be located. For the time being, the fixed
address is being retained for the traditional multiboot path.
As an additional benefit (at least from my pov) it allows confining
the visibility of the BOOT_TRAMPOLINE definition to just the boot
code.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Diffstat (limited to 'xen/arch/x86/boot/head.S')
| -rw-r--r-- | xen/arch/x86/boot/head.S | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S index 0c59f2a750..d092579462 100644 --- a/xen/arch/x86/boot/head.S +++ b/xen/arch/x86/boot/head.S @@ -9,7 +9,7 @@ .text .code32 -#undef bootsym_phys +#define BOOT_TRAMPOLINE 0x7c000 #define sym_phys(sym) ((sym) - __XEN_VIRT_START) #define bootsym_phys(sym) ((sym) - trampoline_start + BOOT_TRAMPOLINE) @@ -189,6 +189,17 @@ __start: mov %edi,sym_phys(idle_pg_table_l2) + (__PAGE_OFFSET>>18) #endif + /* Apply relocations to bootstrap trampoline. */ + mov $BOOT_TRAMPOLINE,%edx + mov $sym_phys(__trampoline_rel_start),%edi + mov %edx,sym_phys(trampoline_phys) +1: + mov (%edi),%eax + add %edx,(%edi,%eax) + add $4,%edi + cmp $sym_phys(__trampoline_rel_stop),%edi + jb 1b + /* Copy bootstrap trampoline to low memory, below 1MB. */ mov $sym_phys(trampoline_start),%esi mov $bootsym_phys(trampoline_start),%edi |