Make aarch64 crt0/lds more like x86_64

Binutils 2.38 now supports efi-app-aarch64 so
to use this we must add a dummy reloc section
and remove the PE header definition from crt0
as this will conflict with the version added
by objcopy

Signed-off-by: Callum Farmer <gmbr3@opensuse.org>

2 files changed, 35 insertions, 97 deletions

diff --git a/gnuefi/crt0-efi-aarch64.S b/gnuefi/crt0-efi-aarch64.S
index a0687b1..a9eda65 100644
--- a/gnuefi/crt0-efi-aarch64.S
+++ b/gnuefi/crt0-efi-aarch64.S
@@ -16,100 +16,10 @@
  * either version 2 of the License, or (at your option) any later version.
  */
 
-	.section	.text.head
-
-	/*
-	 * Magic "MZ" signature for PE/COFF
-	 */
-	.globl	ImageBase
-ImageBase:
-	.ascii	"MZ"
-	.skip	58				// 'MZ' + pad + offset == 64
-	.long	pe_header - ImageBase		// Offset to the PE header.
-pe_header:
-	.ascii	"PE"
-	.short 	0
-coff_header:
-	.short	0xaa64				// AArch64
-	.short	2				// nr_sections
-	.long	0 				// TimeDateStamp
-	.long	0				// PointerToSymbolTable
-	.long	0				// NumberOfSymbols
-	.short	section_table - optional_header	// SizeOfOptionalHeader
-	.short	0x206				// Characteristics.
-						// IMAGE_FILE_DEBUG_STRIPPED |
-						// IMAGE_FILE_EXECUTABLE_IMAGE |
-						// IMAGE_FILE_LINE_NUMS_STRIPPED
-optional_header:
-	.short	0x20b				// PE32+ format
-	.byte	0x02				// MajorLinkerVersion
-	.byte	0x14				// MinorLinkerVersion
-	.long	_data - _start			// SizeOfCode
-	.long	_data_size			// SizeOfInitializedData
-	.long	0				// SizeOfUninitializedData
-	.long	_start - ImageBase		// AddressOfEntryPoint
-	.long	_start - ImageBase		// BaseOfCode
-
-extra_header_fields:
-	.quad	0				// ImageBase
-	.long	0x1000				// SectionAlignment
-	.long	0x200				// FileAlignment
-	.short	0				// MajorOperatingSystemVersion
-	.short	0				// MinorOperatingSystemVersion
-	.short	0				// MajorImageVersion
-	.short	0				// MinorImageVersion
-	.short	0				// MajorSubsystemVersion
-	.short	0				// MinorSubsystemVersion
-	.long	0				// Win32VersionValue
-
-	.long	_edata - ImageBase		// SizeOfImage
-
-	// Everything before the kernel image is considered part of the header
-	.long	_start - ImageBase		// SizeOfHeaders
-	.long	0				// CheckSum
-	.short	EFI_SUBSYSTEM			// Subsystem
-	.short	0				// DllCharacteristics
-	.quad	0				// SizeOfStackReserve
-	.quad	0				// SizeOfStackCommit
-	.quad	0				// SizeOfHeapReserve
-	.quad	0				// SizeOfHeapCommit
-	.long	0				// LoaderFlags
-	.long	0x6				// NumberOfRvaAndSizes
-
-	.quad	0				// ExportTable
-	.quad	0				// ImportTable
-	.quad	0				// ResourceTable
-	.quad	0				// ExceptionTable
-	.quad	0				// CertificationTable
-	.quad	0				// BaseRelocationTable
-
-	// Section table
-section_table:
-	.ascii	".text\0\0\0"
-	.long	_data - _start		// VirtualSize
-	.long	_start - ImageBase	// VirtualAddress
-	.long	_data - _start		// SizeOfRawData
-	.long	_start - ImageBase	// PointerToRawData
-
-	.long	0		// PointerToRelocations (0 for executables)
-	.long	0		// PointerToLineNumbers (0 for executables)
-	.short	0		// NumberOfRelocations  (0 for executables)
-	.short	0		// NumberOfLineNumbers  (0 for executables)
-	.long	0x60000020	// Characteristics (section flags)
-
-	.ascii	".data\0\0\0"
-	.long	_data_size		// VirtualSize
-	.long	_data - ImageBase	// VirtualAddress
-	.long	_data_size		// SizeOfRawData
-	.long	_data - ImageBase	// PointerToRawData
-
-	.long	0		// PointerToRelocations (0 for executables)
-	.long	0		// PointerToLineNumbers (0 for executables)
-	.short	0		// NumberOfRelocations  (0 for executables)
-	.short	0		// NumberOfLineNumbers  (0 for executables)
-	.long	0xc0000040	// Characteristics (section flags)
-
+	.text
 	.align		12
+
+	.globl _start
 _start:
 	stp		x29, x30, [sp, #-32]!
 	mov		x29, sp
@@ -129,6 +39,19 @@ _start:
 0:	ldp		x29, x30, [sp], #32
 	ret
 
+	// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
+ 
+ 	.data
+dummy:	.long	0
+
+#define IMAGE_REL_ABSOLUTE	0
+ 	.section .reloc, "a"
+label1:
+	.long	dummy-label1				// Page RVA
+	.long	12					// Block Size (2*4+2*2), must be aligned by 32 Bits
+	.word	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
+	.word	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
+
 #if defined(__ELF__) && defined(__linux__)
 	.section .note.GNU-stack,"",%progbits
 #endif
diff --git a/gnuefi/elf_aarch64_efi.lds b/gnuefi/elf_aarch64_efi.lds
index 6bfede3..1774d76 100644
--- a/gnuefi/elf_aarch64_efi.lds
+++ b/gnuefi/elf_aarch64_efi.lds
@@ -3,9 +3,18 @@ OUTPUT_ARCH(aarch64)
 ENTRY(_start)
 SECTIONS
 {
-  .text 0x0 : {
+  . = 0;
+  ImageBase = .;
+  /* .hash and/or .gnu.hash MUST come first! */
+  .hash : { *(.hash) }
+  .gnu.hash : { *(.gnu.hash) }
+  . = ALIGN(4096);
+  .eh_frame : 
+  { 
+    *(.eh_frame)
+  }
+  .text : {
     _text = .;
-    *(.text.head)
     *(.text)
     *(.text.*)
     *(.gnu.linkonce.t.*)
@@ -15,6 +24,11 @@ SECTIONS
   }
   _etext = .;
   _text_size = . - _text;
+  . = ALIGN(4096);
+  .reloc :
+  {
+   *(.reloc)
+  }
   . = DATA_SEGMENT_ALIGN (CONSTANT (MAXPAGESIZE), CONSTANT (COMMONPAGESIZE));
   .dynamic  : { *(.dynamic) }
   .data :
@@ -36,6 +50,7 @@ SECTIONS
    *(.dynbss)
    *(.bss)
    *(COMMON)
+   *(.rel.local)
    . = ALIGN(16);
    _bss_end = .;
   }
@@ -55,9 +70,9 @@ SECTIONS
   . = ALIGN(4096);
   .note.gnu.build-id : { *(.note.gnu.build-id) }
   . = DATA_SEGMENT_END (.);
-  /DISCARD/ :
+  .ignored.reloc :
   {
-    *(.rel.reloc)
+    *(.rela.reloc)
     *(.eh_frame)
     *(.note.GNU-stack)
   }