Make our dummy .reloc sections not depend on section order.

Currently on x64 we manually build a dummy .reloc table entry by using a
symbol in .text and subtracting its address from another symbol that's
inside the .reloc section.  On ia32 we just use its location.  In either
case, if the linker puts either section in a location we're not
expecting, the .reloc table winds up having invalid values, and the PE
loader will fail to load the binary.

This changes it to be two symbols that are both in .text, making the
result unrelated to the section order or location.

It's not clear to me that these .reloc entries are actually necessary at
all, but I'm going to leave them in place for now, in case they are.

Ref: rhboot/gnu-efi@9fb55de
Co-authored-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Callum Farmer <gmbr3@opensuse.org>

gnuefi/crt0-efi-aarch64-local.S

@@ -172,12 +172,12 @@ _start:
 	// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
 
  	.data
-dummy:	.4byte	0
+dummy0:	.4byte	0
+dummy1:	.4byte	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .reloc, "a"
-label1:
-	.4byte	dummy-label1				// Page RVA
+ 	.section .reloc, "a", %progbits
+	.4byte	dummy1 - dummy0				// Page RVA
 	.4byte	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy

gnuefi/crt0-efi-aarch64.S

@@ -43,12 +43,12 @@ _start:
 	// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
 
  	.data
-dummy:	.4byte	0
+dummy0:	.4byte	0
+dummy1:	.4byte	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .reloc, "a"
-label1:
-	.4byte	dummy-label1				// Page RVA
+ 	.section .reloc, "a", %progbits
+	.4byte	dummy1 - dummy0				// Page RVA
 	.4byte	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy

gnuefi/crt0-efi-arm.S

@@ -177,11 +177,12 @@ _start:
 // hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
 
  	.data
-dummy:	.4byte	0
+dummy0:	.4byte	0
+dummy1:	.4byte	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .areloc
- 	.4byte	dummy					// Page RVA
+ 	.section .areloc, "a", %progbits
+ 	.4byte	dummy1 - dummy0					// Page RVA
 	.4byte	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy

gnuefi/crt0-efi-ia32-local.S

@@ -163,11 +163,12 @@ _start:
 // hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
 
  	.data
-dummy:	.4byte	0
+dummy0:	.4byte	0
+dummy1:	.4byte	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .reloc
- 	.4byte	dummy					// Page RVA
+ 	.section .reloc, "a", %progbits
+ 	.4byte	dummy1 - dummy0					// Page RVA
 	.4byte	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy

gnuefi/crt0-efi-ia32.S

@@ -68,11 +68,12 @@ _start:
  	// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
 
  	.data
-dummy:	.4byte	0
+dummy0:	.4byte	0
+dummy1:	.4byte	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .reloc
- 	.4byte	dummy					// Page RVA
+ 	.section .reloc, "a", %progbits
+ 	.4byte	dummy1 - dummy0					// Page RVA
 	.4byte	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy

gnuefi/crt0-efi-ia64.S

@@ -80,7 +80,7 @@ _start_plabel:
 
 #define IMAGE_REL_BASED_DIR64	10
 
-	.section .reloc, "a"
+	.section .reloc, "a", %progbits
 	data4	_start_plabel				// Page RVA
 	data4	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
 	data2	(IMAGE_REL_BASED_DIR64<<12) +  0	// reloc for plabel's entry point

gnuefi/crt0-efi-loongarch64.S

@@ -45,12 +45,13 @@ _start:
 // hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
 
  	.data
-dummy:	.4byte	0
+dummy0:	.4byte	0
+dummy1:	.4byte	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .reloc, "a"
+ 	.section .reloc, "a", %progbits
 label1:
-	.4byte	dummy-label1				// Page RVA
+	.4byte	dummy1 - dummy0				// Page RVA
 	.4byte	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy

gnuefi/crt0-efi-riscv64-local.S

@@ -170,12 +170,13 @@ _start:
 // hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
 
  	.data
-dummy:	.4byte	0
+dummy0:	.4byte	0
+dummy1:	.4byte	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .reloc, "a"
+ 	.section .reloc, "a", %progbits
 label1:
-	.4byte	dummy-label1				// Page RVA
+	.4byte	dummy1 - dummy0				// Page RVA
 	.4byte	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy

gnuefi/crt0-efi-riscv64.S

@@ -38,12 +38,13 @@ _start:
 // hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
 
  	.data
-dummy:	.4byte	0
+dummy0:	.4byte	0
+dummy1:	.4byte	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .reloc, "a"
+ 	.section .reloc, "a", %progbits
 label1:
-	.4byte	dummy-label1				// Page RVA
+	.4byte	dummy1 - dummy0				// Page RVA
 	.4byte	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy

gnuefi/crt0-efi-x86_64.S

@@ -66,12 +66,13 @@ _start:
  	// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
 
  	.data
-dummy:	.4byte	0
+dummy0:	.4byte	0
+dummy1:	.4byte	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .reloc, "a"
+ 	.section .reloc, "a", %progbits
 label1:
-	.4byte	dummy-label1				// Page RVA
+	.4byte	dummy1 - dummy0				// Page RVA
 	.4byte	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
 	.2byte	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy