From 08f87f769b595151be1afeff53e144f543faa614 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 06 Dec 2023 09:51:13 +0000
Subject: [PATCH] add dts config

---
 kernel/arch/x86/platform/efi/efi_thunk_64.S |  122 +++++++---------------------------------
 1 files changed, 22 insertions(+), 100 deletions(-)

diff --git a/kernel/arch/x86/platform/efi/efi_thunk_64.S b/kernel/arch/x86/platform/efi/efi_thunk_64.S
index 46c58b0..9eac088 100644
--- a/kernel/arch/x86/platform/efi/efi_thunk_64.S
+++ b/kernel/arch/x86/platform/efi/efi_thunk_64.S
@@ -22,18 +22,20 @@
 #include <linux/linkage.h>
 #include <asm/page_types.h>
 #include <asm/segment.h>
+#include <asm/nospec-branch.h>
 
 	.text
 	.code64
-ENTRY(efi64_thunk)
+SYM_CODE_START(__efi64_thunk)
 	push	%rbp
 	push	%rbx
 
 	/*
 	 * Switch to 1:1 mapped 32-bit stack pointer.
 	 */
-	movq	%rsp, efi_saved_sp(%rip)
+	movq	%rsp, %rax
 	movq	efi_scratch(%rip), %rsp
+	push	%rax
 
 	/*
 	 * Calculate the physical address of the kernel text.
@@ -41,113 +43,33 @@
 	movq	$__START_KERNEL_map, %rax
 	subq	phys_base(%rip), %rax
 
-	/*
-	 * Push some physical addresses onto the stack. This is easier
-	 * to do now in a code64 section while the assembler can address
-	 * 64-bit values. Note that all the addresses on the stack are
-	 * 32-bit.
-	 */
-	subq	$16, %rsp
-	leaq	efi_exit32(%rip), %rbx
+	leaq	1f(%rip), %rbp
+	leaq	2f(%rip), %rbx
+	subq	%rax, %rbp
 	subq	%rax, %rbx
-	movl	%ebx, 8(%rsp)
 
-	leaq	__efi64_thunk(%rip), %rbx
-	subq	%rax, %rbx
-	call	*%rbx
-
-	movq	efi_saved_sp(%rip), %rsp
-	pop	%rbx
-	pop	%rbp
-	retq
-ENDPROC(efi64_thunk)
-
-/*
- * We run this function from the 1:1 mapping.
- *
- * This function must be invoked with a 1:1 mapped stack.
- */
-ENTRY(__efi64_thunk)
-	movl	%ds, %eax
-	push	%rax
-	movl	%es, %eax
-	push	%rax
-	movl	%ss, %eax
-	push	%rax
-
-	subq	$32, %rsp
-	movl	%esi, 0x0(%rsp)
-	movl	%edx, 0x4(%rsp)
-	movl	%ecx, 0x8(%rsp)
-	movq	%r8, %rsi
-	movl	%esi, 0xc(%rsp)
-	movq	%r9, %rsi
-	movl	%esi,  0x10(%rsp)
-
-	leaq	1f(%rip), %rbx
-	movq	%rbx, func_rt_ptr(%rip)
+	subq	$28, %rsp
+	movl	%ebx, 0x0(%rsp)		/* return address */
+	movl	%esi, 0x4(%rsp)
+	movl	%edx, 0x8(%rsp)
+	movl	%ecx, 0xc(%rsp)
+	movl	%r8d, 0x10(%rsp)
+	movl	%r9d, 0x14(%rsp)
 
 	/* Switch to 32-bit descriptor */
 	pushq	$__KERNEL32_CS
-	leaq	efi_enter32(%rip), %rax
-	pushq	%rax
+	pushq	%rdi			/* EFI runtime service address */
 	lretq
 
-1:	addq	$32, %rsp
-
+1:	movq	24(%rsp), %rsp
 	pop	%rbx
-	movl	%ebx, %ss
-	pop	%rbx
-	movl	%ebx, %es
-	pop	%rbx
-	movl	%ebx, %ds
-
-	/*
-	 * Convert 32-bit status code into 64-bit.
-	 */
-	test	%rax, %rax
-	jz	1f
-	movl	%eax, %ecx
-	andl	$0x0fffffff, %ecx
-	andl	$0xf0000000, %eax
-	shl	$32, %rax
-	or	%rcx, %rax
-1:
+	pop	%rbp
+	ANNOTATE_UNRET_SAFE
 	ret
-ENDPROC(__efi64_thunk)
-
-ENTRY(efi_exit32)
-	movq	func_rt_ptr(%rip), %rax
-	push	%rax
-	mov	%rdi, %rax
-	ret
-ENDPROC(efi_exit32)
+	int3
 
 	.code32
-/*
- * EFI service pointer must be in %edi.
- *
- * The stack should represent the 32-bit calling convention.
- */
-ENTRY(efi_enter32)
-	movl	$__KERNEL_DS, %eax
-	movl	%eax, %ds
-	movl	%eax, %es
-	movl	%eax, %ss
-
-	call	*%edi
-
-	/* We must preserve return value */
-	movl	%eax, %edi
-
-	movl	72(%esp), %eax
-	pushl	$__KERNEL_CS
-	pushl	%eax
-
+2:	pushl	$__KERNEL_CS
+	pushl	%ebp
 	lret
-ENDPROC(efi_enter32)
-
-	.data
-	.balign	8
-func_rt_ptr:		.quad 0
-efi_saved_sp:		.quad 0
+SYM_CODE_END(__efi64_thunk)

--
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