xref: /DragonStub/gnuefi/crt0-efi-loongarch64.S (revision 9e6cb2150bee08e83ec0cdfb8d6c2f83975dd3df)

/*
 * crt0-efi-loongarch64.S - PE/COFF header for LoongArch64 EFI applications
 *
 * Copyright (C) 2021 Loongson Technology Corporation Limited. <zhoumingtao@loongson.cn>
 * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice and this list of conditions, without modification.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License as published by the Free Software Foundation;
 * either version 2 of the License, or (at your option) any later version.
 */

#ifndef EFI_SUBSYSTEM
#define EFI_SUBSYSTEM 0xa
#endif
	.section	.text.head

	/*
	 * Magic "MZ" signature for PE/COFF
	 */
	.globl	ImageBase
ImageBase:
	.ascii	"MZ"
	.skip	58				// 'MZ' + pad + offset == 64
	.4byte	pe_header - ImageBase		// Offset to the PE header.
pe_header:
	.ascii	"PE"
	.2byte 	0
coff_header:
	.2byte	0x6264				// loongarch64 little endian
	.2byte	2				// nr_sections
	.4byte	0 				// TimeDateStamp
	.4byte	0				// PointerToSymbolTable
	.4byte	1				// NumberOfSymbols
	.2byte	section_table - optional_header	// SizeOfOptionalHeader
	.2byte	0x206				// Characteristics.
						// IMAGE_FILE_DEBUG_STRIPPED |
						// IMAGE_FILE_EXECUTABLE_IMAGE |
						// IMAGE_FILE_LINE_NUMS_STRIPPED
optional_header:
	.2byte	0x20b				// PE32+ format
	.byte	0x02				// MajorLinkerVersion
	.byte	0x14				// MinorLinkerVersion
	.4byte	_edata - _start			// SizeOfCode
	.4byte	0				// SizeOfInitializedData
	.4byte	0				// SizeOfUninitializedData
	.4byte	_start - ImageBase		// AddressOfEntryPoint
	.4byte	_start - ImageBase		// BaseOfCode

extra_header_fields:
	.8byte	0				// ImageBase
	.4byte	0x20				// SectionAlignment
	.4byte	0x8				// FileAlignment
	.2byte	0				// MajorOperatingSystemVersion
	.2byte	0				// MinorOperatingSystemVersion
	.2byte	0				// MajorImageVersion
	.2byte	0				// MinorImageVersion
	.2byte	0				// MajorSubsystemVersion
	.2byte	0				// MinorSubsystemVersion
	.4byte	0				// Win32VersionValue

	.4byte	_edata - ImageBase		// SizeOfImage

	// Everything before the kernel image is considered part of the header
	.4byte	_start - ImageBase		// SizeOfHeaders
	.4byte	0				// CheckSum
	.2byte	EFI_SUBSYSTEM			// Subsystem
	.2byte	0				// DllCharacteristics
	.8byte	0				// SizeOfStackReserve
	.8byte	0				// SizeOfStackCommit
	.8byte	0				// SizeOfHeapReserve
	.8byte	0				// SizeOfHeapCommit
	.4byte	0				// LoaderFlags
	.4byte	0x6				// NumberOfRvaAndSizes

	.8byte	0				// ExportTable
	.8byte	0				// ImportTable
	.8byte	0				// ResourceTable
	.8byte	0				// ExceptionTable
	.8byte	0				// CertificationTable
	.8byte	0				// BaseRelocationTable

	// Section table
section_table:

	/*
	 * The EFI application loader requires a relocation section
	 * because EFI applications must be relocatable.  This is a
	 * dummy section as far as we are concerned.
	 */
	.ascii	".reloc"
	.byte	0
	.byte	0			// end of 0 padding of section name
	.4byte	0
	.4byte	0
	.4byte	0			// SizeOfRawData
	.4byte	0			// PointerToRawData
	.4byte	0			// PointerToRelocations
	.4byte	0			// PointerToLineNumbers
	.2byte	0			// NumberOfRelocations
	.2byte	0			// NumberOfLineNumbers
	.4byte	0x42100040		// Characteristics (section flags)


	.ascii	".text"
	.byte	0
	.byte	0
	.byte	0        		// end of 0 padding of section name
	.4byte	_edata - _start		// VirtualSize
	.4byte	_start - ImageBase	// VirtualAddress
	.4byte	_edata - _start		// SizeOfRawData
	.4byte	_start - ImageBase	// PointerToRawData

	.4byte	0			// PointerToRelocations (0 for executables)
	.4byte	0			// PointerToLineNumbers (0 for executables)
	.2byte	0			// NumberOfRelocations  (0 for executables)
	.2byte	0			// NumberOfLineNumbers  (0 for executables)
	.4byte	0xe0500020		// Characteristics (section flags)

	.align  4

	.globl	_start
	.type	_start, @function
_start:
	addi.d	  $sp, $sp, -24
	st.d	  $ra, $sp, 0
	st.d	  $a0, $sp, 8
	st.d 	  $a1, $sp, 16

	move	  $a2, $a0		// a2: ImageHandle
	move	  $a3, $a1 		// a3: SystemTable
	la.local  $a0, ImageBase	// a0: ImageBase
	la.local  $a1, _DYNAMIC		// a1: DynamicSection
	bl        _relocate
	bnez	  $a0, 0f

	ld.d	  $a0, $sp, 8
	ld.d	  $a1, $sp, 16
	bl        efi_main

0:	ld.d	  $ra, $sp, 0
	addi.d	  $sp, $sp, 24
	jr	      $ra
	.end	  _start