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crt0-efi-arm.S revision 1.1 
      1 /*	$NetBSD: crt0-efi-arm.S,v 1.1 2018/08/16 18:17:47 jmcneill Exp $	*/
      2 
      3 /*
      4  * crt0-efi-arm.S - PE/COFF header for ARM EFI applications
      5  *
      6  * Copright (C) 2014 Linaro Ltd. <ard.biesheuvel (at) linaro.org>
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice and this list of conditions, without modification.
     13  * 2. The name of the author may not be used to endorse or promote products
     14  *    derived from this software without specific prior written permission.
     15  *
     16  * Alternatively, this software may be distributed under the terms of the
     17  * GNU General Public License as published by the Free Software Foundation;
     18  * either version 2 of the License, or (at your option) any later version.
     19  */
     20 
     21 	.section	.text.head
     22 
     23 	/*
     24 	 * Magic "MZ" signature for PE/COFF
     25 	 */
     26 	.globl	ImageBase
     27 ImageBase:
     28 	.ascii	"MZ"
     29 	.skip	58				// 'MZ' + pad + offset == 64
     30 	.long	pe_header - ImageBase		// Offset to the PE header.
     31 pe_header:
     32 	.ascii	"PE"
     33 	.short 	0
     34 coff_header:
     35 	.short	0x1c2				// Mixed ARM/Thumb
     36 	.short	2				// nr_sections
     37 	.long	0 				// TimeDateStamp
     38 	.long	0				// PointerToSymbolTable
     39 	.long	1				// NumberOfSymbols
     40 	.short	section_table - optional_header	// SizeOfOptionalHeader
     41 	.short	0x306				// Characteristics.
     42 						// IMAGE_FILE_32BIT_MACHINE |
     43 						// IMAGE_FILE_DEBUG_STRIPPED |
     44 						// IMAGE_FILE_EXECUTABLE_IMAGE |
     45 						// IMAGE_FILE_LINE_NUMS_STRIPPED
     46 optional_header:
     47 	.short	0x10b				// PE32+ format
     48 	.byte	0x02				// MajorLinkerVersion
     49 	.byte	0x14				// MinorLinkerVersion
     50 	.long	_edata - _start			// SizeOfCode
     51 	.long	0				// SizeOfInitializedData
     52 	.long	0				// SizeOfUninitializedData
     53 	.long	_start - ImageBase		// AddressOfEntryPoint
     54 	.long	_start - ImageBase		// BaseOfCode
     55 	.long	0				// BaseOfData
     56 
     57 extra_header_fields:
     58 	.long	0				// ImageBase
     59 	.long	0x20				// SectionAlignment
     60 	.long	0x8				// FileAlignment
     61 	.short	0				// MajorOperatingSystemVersion
     62 	.short	0				// MinorOperatingSystemVersion
     63 	.short	0				// MajorImageVersion
     64 	.short	0				// MinorImageVersion
     65 	.short	0				// MajorSubsystemVersion
     66 	.short	0				// MinorSubsystemVersion
     67 	.long	0				// Win32VersionValue
     68 
     69 	.long	_edata - ImageBase		// SizeOfImage
     70 
     71 	// Everything before the kernel image is considered part of the header
     72 	.long	_start - ImageBase		// SizeOfHeaders
     73 	.long	0				// CheckSum
     74 	.short	EFI_SUBSYSTEM			// Subsystem
     75 	.short	0				// DllCharacteristics
     76 	.long	0				// SizeOfStackReserve
     77 	.long	0				// SizeOfStackCommit
     78 	.long	0				// SizeOfHeapReserve
     79 	.long	0				// SizeOfHeapCommit
     80 	.long	0				// LoaderFlags
     81 	.long	0x6				// NumberOfRvaAndSizes
     82 
     83 	.quad	0				// ExportTable
     84 	.quad	0				// ImportTable
     85 	.quad	0				// ResourceTable
     86 	.quad	0				// ExceptionTable
     87 	.quad	0				// CertificationTable
     88 	.quad	0				// BaseRelocationTable
     89 
     90 	// Section table
     91 section_table:
     92 
     93 	/*
     94 	 * The EFI application loader requires a relocation section
     95 	 * because EFI applications must be relocatable.  This is a
     96 	 * dummy section as far as we are concerned.
     97 	 */
     98 	.ascii	".reloc"
     99 	.byte	0
    100 	.byte	0			// end of 0 padding of section name
    101 	.long	0
    102 	.long	0
    103 	.long	0			// SizeOfRawData
    104 	.long	0			// PointerToRawData
    105 	.long	0			// PointerToRelocations
    106 	.long	0			// PointerToLineNumbers
    107 	.short	0			// NumberOfRelocations
    108 	.short	0			// NumberOfLineNumbers
    109 	.long	0x42100040		// Characteristics (section flags)
    110 
    111 
    112 	.ascii	".text"
    113 	.byte	0
    114 	.byte	0
    115 	.byte	0        		// end of 0 padding of section name
    116 	.long	_edata - _start		// VirtualSize
    117 	.long	_start - ImageBase	// VirtualAddress
    118 	.long	_edata - _start		// SizeOfRawData
    119 	.long	_start - ImageBase	// PointerToRawData
    120 
    121 	.long	0		// PointerToRelocations (0 for executables)
    122 	.long	0		// PointerToLineNumbers (0 for executables)
    123 	.short	0		// NumberOfRelocations  (0 for executables)
    124 	.short	0		// NumberOfLineNumbers  (0 for executables)
    125 	.long	0xe0500020	// Characteristics (section flags)
    126 
    127 _start:
    128 	stmfd		sp!, {r0-r2, lr}
    129 
    130 	mov		r2, r0
    131 	mov		r3, r1
    132 	adr		r1, .L_DYNAMIC
    133 	ldr		r0, [r1]
    134 	add		r1, r0, r1
    135 	adr		r0, ImageBase
    136 	bl		_relocate
    137 	teq		r0, #0
    138 	bne		0f
    139 
    140 	ldmfd		sp, {r0-r1}
    141 	bl		efi_main
    142 
    143 0:	add		sp, sp, #12
    144 	ldr		pc, [sp], #4
    145 
    146 .L_DYNAMIC:
    147 	.word		_DYNAMIC - .
    148