3 files changed, 38 insertions, 13 deletions

diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index a0559930a180..c85e3ac99bba 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -33,6 +33,9 @@
 	__HEAD
 ENTRY(startup_32)
 #ifdef CONFIG_EFI_STUB
+	jmp	preferred_addr
+
+	.balign	0x10
 	/*
 	 * We don't need the return address, so set up the stack so
 	 * efi_main() can find its arugments.
@@ -41,12 +44,17 @@ ENTRY(startup_32)
 
 	call	efi_main
 	cmpl	$0, %eax
-	je	preferred_addr
 	movl	%eax, %esi
-	call	1f
+	jne	2f
 1:
+	/* EFI init failed, so hang. */
+	hlt
+	jmp	1b
+2:
+	call	3f
+3:
 	popl	%eax
-	subl	$1b, %eax
+	subl	$3b, %eax
 	subl	BP_pref_address(%esi), %eax
 	add	BP_code32_start(%esi), %eax
 	leal	preferred_addr(%eax), %eax
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 558d76ce23bc..87e03a13d8e3 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -200,18 +200,28 @@ ENTRY(startup_64)
 	 * entire text+data+bss and hopefully all of memory.
 	 */
 #ifdef CONFIG_EFI_STUB
-	pushq	%rsi
+	/*
+	 * The entry point for the PE/COFF executable is 0x210, so only
+	 * legacy boot loaders will execute this jmp.
+	 */
+	jmp	preferred_addr
+
+	.org 0x210
 	mov	%rcx, %rdi
 	mov	%rdx, %rsi
 	call	efi_main
-	popq	%rsi
-	cmpq	$0,%rax
-	je	preferred_addr
 	movq	%rax,%rsi
-	call	1f
+	cmpq	$0,%rax
+	jne	2f
 1:
+	/* EFI init failed, so hang. */
+	hlt
+	jmp	1b
+2:
+	call	3f
+3:
 	popq	%rax
-	subq	$1b, %rax
+	subq	$3b, %rax
 	subq	BP_pref_address(%rsi), %rax
 	add	BP_code32_start(%esi), %eax
 	leaq	preferred_addr(%rax), %rax
diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c
index ed549767a231..24443a332083 100644
--- a/arch/x86/boot/tools/build.c
+++ b/arch/x86/boot/tools/build.c
@@ -205,8 +205,13 @@ int main(int argc, char ** argv)
 	put_unaligned_le32(file_sz, &buf[pe_header + 0x50]);
 
 #ifdef CONFIG_X86_32
-	/* Address of entry point */
-	put_unaligned_le32(i, &buf[pe_header + 0x28]);
+	/*
+	 * Address of entry point.
+	 *
+	 * The EFI stub entry point is +16 bytes from the start of
+	 * the .text section.
+	 */
+	put_unaligned_le32(i + 16, &buf[pe_header + 0x28]);
 
 	/* .text size */
 	put_unaligned_le32(file_sz, &buf[pe_header + 0xb0]);
@@ -217,9 +222,11 @@ int main(int argc, char ** argv)
 	/*
 	 * Address of entry point. startup_32 is at the beginning and
 	 * the 64-bit entry point (startup_64) is always 512 bytes
-	 * after.
+	 * after. The EFI stub entry point is 16 bytes after that, as
+	 * the first instruction allows legacy loaders to jump over
+	 * the EFI stub initialisation
 	 */
-	put_unaligned_le32(i + 512, &buf[pe_header + 0x28]);
+	put_unaligned_le32(i + 528, &buf[pe_header + 0x28]);
 
 	/* .text size */
 	put_unaligned_le32(file_sz, &buf[pe_header + 0xc0]);