From e5e4452190fd42838db4b11912bd8cd03fa61e08 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Tue, 16 Apr 2024 05:22:58 +0200
Subject: Merging upstream version 6.1.85.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 arch/x86/boot/compressed/efi_mixed.S | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

(limited to 'arch/x86/boot/compressed/efi_mixed.S')

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)
-- 
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