xen: Add PVH boot entry code

Add the code for the Xen PVH mode boot entry.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Hans van Kranenburg <hans@knorrie.org>
This commit is contained in:
Juergen Gross 2018-12-07 13:11:38 +01:00 committed by Daniel Kiper
parent 0b3e4eb2d2
commit 1a4d83af2f

View file

@ -19,11 +19,63 @@
#include <config.h>
#include <grub/symbol.h>
#include <grub/machine/memory.h>
.file "startup_pvh.S"
.text
.globl start, _start
.code32
start:
_start:
cld
lgdt gdtdesc
ljmp $GRUB_MEMORY_MACHINE_PROT_MODE_CSEG, $1f
1:
movl $GRUB_MEMORY_MACHINE_PROT_MODE_DSEG, %eax
mov %eax, %ds
mov %eax, %es
mov %eax, %fs
mov %eax, %gs
mov %eax, %ss
leal LOCAL(stack_end), %esp
/* Save address of start info structure. */
mov %ebx, pvh_start_info
call EXT_C(grub_main)
/* Doesn't return. */
.p2align 3
gdt:
.word 0, 0
.byte 0, 0, 0, 0
/* -- code segment --
* base = 0x00000000, limit = 0xFFFFF (4 KiB Granularity), present
* type = 32bit code execute/read, DPL = 0
*/
.word 0xFFFF, 0
.byte 0, 0x9A, 0xCF, 0
/* -- data segment --
* base = 0x00000000, limit 0xFFFFF (4 KiB Granularity), present
* type = 32 bit data read/write, DPL = 0
*/
.word 0xFFFF, 0
.byte 0, 0x92, 0xCF, 0
.p2align 3
/* this is the GDT descriptor */
gdtdesc:
.word 0x17 /* limit */
.long gdt /* addr */
.p2align 2
/* Saved pointer to start info structure. */
.globl pvh_start_info
pvh_start_info:
.long 0
.bss
.space GRUB_MEMORY_MACHINE_PROT_STACK_SIZE
LOCAL(stack_end):