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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/x86/platform/efi/efi_stub_64.S
Initial import
Diffstat (limited to 'arch/x86/platform/efi/efi_stub_64.S')
-rw-r--r--arch/x86/platform/efi/efi_stub_64.S98
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/efi_stub_64.S b/arch/x86/platform/efi/efi_stub_64.S
new file mode 100644
index 000000000..86d0f9e08
--- /dev/null
+++ b/arch/x86/platform/efi/efi_stub_64.S
@@ -0,0 +1,98 @@
+/*
+ * Function calling ABI conversion from Linux to EFI for x86_64
+ *
+ * Copyright (C) 2007 Intel Corp
+ * Bibo Mao <bibo.mao@intel.com>
+ * Huang Ying <ying.huang@intel.com>
+ */
+
+#include <linux/linkage.h>
+#include <asm/segment.h>
+#include <asm/msr.h>
+#include <asm/processor-flags.h>
+#include <asm/page_types.h>
+
+#define SAVE_XMM \
+ mov %rsp, %rax; \
+ subq $0x70, %rsp; \
+ and $~0xf, %rsp; \
+ mov %rax, (%rsp); \
+ mov %cr0, %rax; \
+ clts; \
+ mov %rax, 0x8(%rsp); \
+ movaps %xmm0, 0x60(%rsp); \
+ movaps %xmm1, 0x50(%rsp); \
+ movaps %xmm2, 0x40(%rsp); \
+ movaps %xmm3, 0x30(%rsp); \
+ movaps %xmm4, 0x20(%rsp); \
+ movaps %xmm5, 0x10(%rsp)
+
+#define RESTORE_XMM \
+ movaps 0x60(%rsp), %xmm0; \
+ movaps 0x50(%rsp), %xmm1; \
+ movaps 0x40(%rsp), %xmm2; \
+ movaps 0x30(%rsp), %xmm3; \
+ movaps 0x20(%rsp), %xmm4; \
+ movaps 0x10(%rsp), %xmm5; \
+ mov 0x8(%rsp), %rsi; \
+ mov %rsi, %cr0; \
+ mov (%rsp), %rsp
+
+ /* stolen from gcc */
+ .macro FLUSH_TLB_ALL
+ movq %r15, efi_scratch(%rip)
+ movq %r14, efi_scratch+8(%rip)
+ movq %cr4, %r15
+ movq %r15, %r14
+ andb $0x7f, %r14b
+ movq %r14, %cr4
+ movq %r15, %cr4
+ movq efi_scratch+8(%rip), %r14
+ movq efi_scratch(%rip), %r15
+ .endm
+
+ .macro SWITCH_PGT
+ cmpb $0, efi_scratch+24(%rip)
+ je 1f
+ movq %r15, efi_scratch(%rip) # r15
+ # save previous CR3
+ movq %cr3, %r15
+ movq %r15, efi_scratch+8(%rip) # prev_cr3
+ movq efi_scratch+16(%rip), %r15 # EFI pgt
+ movq %r15, %cr3
+ 1:
+ .endm
+
+ .macro RESTORE_PGT
+ cmpb $0, efi_scratch+24(%rip)
+ je 2f
+ movq efi_scratch+8(%rip), %r15
+ movq %r15, %cr3
+ movq efi_scratch(%rip), %r15
+ FLUSH_TLB_ALL
+ 2:
+ .endm
+
+ENTRY(efi_call)
+ SAVE_XMM
+ mov (%rsp), %rax
+ mov 8(%rax), %rax
+ subq $48, %rsp
+ mov %r9, 32(%rsp)
+ mov %rax, 40(%rsp)
+ mov %r8, %r9
+ mov %rcx, %r8
+ mov %rsi, %rcx
+ SWITCH_PGT
+ call *%rdi
+ RESTORE_PGT
+ addq $48, %rsp
+ RESTORE_XMM
+ ret
+ENDPROC(efi_call)
+
+ .data
+ENTRY(efi_scratch)
+ .fill 3,8,0
+ .byte 0
+ .quad 0