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-rw-r--r--arch/x86/boot/compressed/efi_mixed.S29
1 files changed, 24 insertions, 5 deletions
diff --git a/arch/x86/boot/compressed/efi_mixed.S b/arch/x86/boot/compressed/efi_mixed.S
index 8232c5b2a..fb6d60dcd 100644
--- a/arch/x86/boot/compressed/efi_mixed.S
+++ b/arch/x86/boot/compressed/efi_mixed.S
@@ -15,10 +15,12 @@
*/
#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
#include <asm/msr.h>
#include <asm/page_types.h>
#include <asm/processor-flags.h>
#include <asm/segment.h>
+#include <asm/setup.h>
.code64
.text
@@ -49,6 +51,11 @@ SYM_FUNC_START(startup_64_mixed_mode)
lea efi32_boot_args(%rip), %rdx
mov 0(%rdx), %edi
mov 4(%rdx), %esi
+
+ /* Switch to the firmware's stack */
+ movl efi32_boot_sp(%rip), %esp
+ andl $~7, %esp
+
#ifdef CONFIG_EFI_HANDOVER_PROTOCOL
mov 8(%rdx), %edx // saved bootparams pointer
test %edx, %edx
@@ -150,6 +157,7 @@ SYM_FUNC_END(__efi64_thunk)
SYM_FUNC_START(efi32_stub_entry)
call 1f
1: popl %ecx
+ leal (efi32_boot_args - 1b)(%ecx), %ebx
/* Clear BSS */
xorl %eax, %eax
@@ -164,6 +172,7 @@ SYM_FUNC_START(efi32_stub_entry)
popl %ecx
popl %edx
popl %esi
+ movl %esi, 8(%ebx)
jmp efi32_entry
SYM_FUNC_END(efi32_stub_entry)
#endif
@@ -240,8 +249,6 @@ SYM_FUNC_END(efi_enter32)
*
* Arguments: %ecx image handle
* %edx EFI system table pointer
- * %esi struct bootparams pointer (or NULL when not using
- * the EFI handover protocol)
*
* Since this is the point of no return for ordinary execution, no registers
* are considered live except for the function parameters. [Note that the EFI
@@ -260,13 +267,25 @@ SYM_FUNC_START_LOCAL(efi32_entry)
/* Store firmware IDT descriptor */
sidtl (efi32_boot_idt - 1b)(%ebx)
+ /* Store firmware stack pointer */
+ movl %esp, (efi32_boot_sp - 1b)(%ebx)
+
/* Store boot arguments */
leal (efi32_boot_args - 1b)(%ebx), %ebx
movl %ecx, 0(%ebx)
movl %edx, 4(%ebx)
- movl %esi, 8(%ebx)
movb $0x0, 12(%ebx) // efi_is64
+ /*
+ * Allocate some memory for a temporary struct boot_params, which only
+ * needs the minimal pieces that startup_32() relies on.
+ */
+ subl $PARAM_SIZE, %esp
+ movl %esp, %esi
+ movl $PAGE_SIZE, BP_kernel_alignment(%esi)
+ movl $_end - 1b, BP_init_size(%esi)
+ subl $startup_32 - 1b, BP_init_size(%esi)
+
/* Disable paging */
movl %cr0, %eax
btrl $X86_CR0_PG_BIT, %eax
@@ -292,8 +311,7 @@ SYM_FUNC_START(efi32_pe_entry)
movl 8(%ebp), %ecx // image_handle
movl 12(%ebp), %edx // sys_table
- xorl %esi, %esi
- jmp efi32_entry // pass %ecx, %edx, %esi
+ jmp efi32_entry // pass %ecx, %edx
// no other registers remain live
2: popl %edi // restore callee-save registers
@@ -324,5 +342,6 @@ SYM_DATA_END(efi32_boot_idt)
SYM_DATA_LOCAL(efi32_boot_cs, .word 0)
SYM_DATA_LOCAL(efi32_boot_ds, .word 0)
+SYM_DATA_LOCAL(efi32_boot_sp, .long 0)
SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0, 0)
SYM_DATA(efi_is64, .byte 1)