u-boot/arch/arm/cpu/armv8/linux-kernel-image-header-vars.h
Stephen Warren 8163faf952 ARMv8: add optional Linux kernel image header
Allow placing a Linux kernel image header at the start of the U-Boot
binary. This is useful since the image header reports the amount of memory
(BSS and similar) that U-Boot needs to use, but that isn't part of the
binary size. This can be used by the code that loads U-Boot into memory to
determine where to load U-Boot, based on other users of memory.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
2018-01-12 09:52:11 -07:00

86 lines
2.7 KiB
C

/*
* (C) Copyright 2017 NVIDIA Corporation <www.nvidia.com>
*
* Derived from Linux kernel v4.14 files:
*
* arch/arm64/include/asm/assembler.h:
* Based on arch/arm/include/asm/assembler.h, arch/arm/mm/proc-macros.S
* Copyright (C) 1996-2000 Russell King
* Copyright (C) 2012 ARM Ltd.
*
* arch/arm64/kernel/head.S:
* Based on arch/arm/kernel/head.S
* Copyright (C) 1994-2002 Russell King
* Copyright (C) 2003-2012 ARM Ltd.
* Authors: Catalin Marinas <catalin.marinas@arm.com>
* Will Deacon <will.deacon@arm.com>
*
* arch/arm64/kernel/image.h:
* Copyright (C) 2014 ARM Ltd.
*
* SPDX-License-Identifier: GPL-2.0
*/
/*
* 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)
#define __MAX(a, b) (((a) > (b)) ? (a) : (b))
#define __CODE_DATA_SIZE (__bss_start - _start)
#define __BSS_SIZE (__bss_end - __bss_start)
#ifdef CONFIG_SYS_INIT_SP_BSS_OFFSET
#define __MAX_EXTRA_RAM_USAGE __MAX(__BSS_SIZE, CONFIG_SYS_INIT_SP_BSS_OFFSET)
#else
#define __MAX_EXTRA_RAM_USAGE __BSS_SIZE
#endif
#define __MEM_USAGE (__CODE_DATA_SIZE + __MAX_EXTRA_RAM_USAGE)
#ifdef CONFIG_CPU_BIG_ENDIAN
#define __HEAD_FLAG_BE 1
#else
#define __HEAD_FLAG_BE 0
#endif
#define __HEAD_FLAG_PAGE_SIZE 1 /* 4K hard-coded */
#define __HEAD_FLAG_PHYS_BASE 1
#define __HEAD_FLAGS ((__HEAD_FLAG_BE << 0) | \
(__HEAD_FLAG_PAGE_SIZE << 1) | \
(__HEAD_FLAG_PHYS_BASE << 3))
#define TEXT_OFFSET (CONFIG_SYS_TEXT_BASE - \
CONFIG_LNX_KRNL_IMG_TEXT_OFFSET_BASE)
/*
* 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, __MEM_USAGE); \
DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET); \
DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS);
HEAD_SYMBOLS