text: /*
   * Linker script macros to generate Image header fields.
   *
   * Copyright (C) 2014 ARM Ltd.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  #ifndef __ASM_IMAGE_H
  #define __ASM_IMAGE_H
  
  #ifndef LINKER_SCRIPT
  #error This file should only be included in vmlinux.lds.S
  #endif
  
  /*
   * There aren't any ELF relocations we can use to endian-swap values known only
   * at link time (e.g. the subtraction of two symbol addresses), so we must get
   * the linker to endian-swap certain values before emitting them.
   *
   * Note that, in order for this to work when building the ELF64 PIE executable
   * (for KASLR), these values should not be referenced via R_AARCH64_ABS64
   * relocations, since these are fixed up at runtime rather than at build time
   * when PIE is in effect. So we need to split them up in 32-bit high and low
   * words.
   */
  #ifdef CONFIG_CPU_BIG_ENDIAN
  #define DATA_LE32(data)				\
  	((((data) & 0x000000ff) << 24) |	\
  	 (((data) & 0x0000ff00) << 8)  |	\
  	 (((data) & 0x00ff0000) >> 8)  |	\
  	 (((data) & 0xff000000) >> 24))
  #else
  #define DATA_LE32(data) ((data) & 0xffffffff)
  #endif
  
  #define DEFINE_IMAGE_LE64(sym, data)				\
  	sym##_lo32 = DATA_LE32((data) & 0xffffffff);		\
  	sym##_hi32 = DATA_LE32((data) >> 32)
  
  #ifdef CONFIG_CPU_BIG_ENDIAN
  #define __HEAD_FLAG_BE		1
  #else
  #define __HEAD_FLAG_BE		0
  #endif
  
  #define __HEAD_FLAG_PAGE_SIZE	((PAGE_SHIFT - 10) / 2)
  
  #define __HEAD_FLAG_PHYS_BASE	1
  
  #define __HEAD_FLAGS		((__HEAD_FLAG_BE << 0) |	\
  				 (__HEAD_FLAG_PAGE_SIZE << 1) |	\
  				 (__HEAD_FLAG_PHYS_BASE << 3))
  
  /*
   * These will output as part of the Image header, which should be little-endian
   * regardless of the endianness of the kernel. While constant values could be
   * endian swapped in head.S, all are done here for consistency.
   */
  #define HEAD_SYMBOLS						\
  	DEFINE_IMAGE_LE64(_kernel_size_le, _end - _text);	\
  	DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET);	\
  	DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS);
  
  #ifdef CONFIG_EFI
  
  __efistub_stext_offset = stext - _text;
  
  /*
   * Prevent the symbol aliases below from being emitted into the kallsyms
   * table, by forcing them to be absolute symbols (which are conveniently
   * ignored by scripts/kallsyms) rather than section relative symbols.
   * The distinction is only relevant for partial linking, and only for symbols
   * that are defined within a section declaration (which is not the case for
   * the definitions below) so the resulting values will be identical.
   */
  #define KALLSYMS_HIDE(sym)	ABSOLUTE(sym)
  
  /*
   * The EFI stub has its own symbol namespace prefixed by __efistub_, to
   * isolate it from the kernel proper. The following symbols are legally
   * accessed by the stub, so provide some aliases to make them accessible.
   * Only include data symbols here, or text symbols of functions that are
   * guaranteed to be safe when executed at another offset than they were
   * linked at. The routines below are all implemented in assembler in a
   * position independent manner
   */
  __efistub_memcmp		= KALLSYMS_HIDE(__pi_memcmp);
  __efistub_memchr		= KALLSYMS_HIDE(__pi_memchr);
  __efistub_memcpy		= KALLSYMS_HIDE(__pi_memcpy);
  __efistub_memmove		= KALLSYMS_HIDE(__pi_memmove);
  __efistub_memset		= KALLSYMS_HIDE(__pi_memset);
  __efistub_strlen		= KALLSYMS_HIDE(__pi_strlen);
  __efistub_strnlen		= KALLSYMS_HIDE(__pi_strnlen);
  __efistub_strcmp		= KALLSYMS_HIDE(__pi_strcmp);
  __efistub_strncmp		= KALLSYMS_HIDE(__pi_strncmp);
  __efistub_strrchr		= KALLSYMS_HIDE(__pi_strrchr);
  __efistub___flush_dcache_area	= KALLSYMS_HIDE(__pi___flush_dcache_area);
  
  #ifdef CONFIG_KASAN
  __efistub___memcpy		= KALLSYMS_HIDE(__pi_memcpy);
  __efistub___memmove		= KALLSYMS_HIDE(__pi_memmove);
  __efistub___memset		= KALLSYMS_HIDE(__pi_memset);
  #endif
  
  __efistub__text			= KALLSYMS_HIDE(_text);
  __efistub__end			= KALLSYMS_HIDE(_end);
  __efistub__edata		= KALLSYMS_HIDE(_edata);
  __efistub_screen_info		= KALLSYMS_HIDE(screen_info);
  
  #endif
  
  #endif /* __ASM_IMAGE_H */
  