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authorStephen Warren <swarren@nvidia.com>2018-01-03 14:31:51 -0700
committerTom Warren <twarren@nvidia.com>2018-01-12 09:52:11 -0700
commit8163faf952c467b01758b8a9a0dc8538e487aa9a (patch)
tree2964e95d8dccd8367b2115876e7e481a32c2f0ff /arch/arm/include
parentf097532d279dd7a6ab2d579425d1318051ac1f8d (diff)
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>
Diffstat (limited to 'arch/arm/include')
-rw-r--r--arch/arm/include/asm/boot0-linux-kernel-header.h49
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/arm/include/asm/boot0-linux-kernel-header.h b/arch/arm/include/asm/boot0-linux-kernel-header.h
new file mode 100644
index 0000000000..ca28780daa
--- /dev/null
+++ b/arch/arm/include/asm/boot0-linux-kernel-header.h
@@ -0,0 +1,49 @@
+/*
+ * (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
+ */
+
+ /*
+ * Emit a 64-bit absolute little endian symbol reference in a way that
+ * ensures that it will be resolved at build time, even when building a
+ * PIE binary. This requires cooperation from the linker script, which
+ * must emit the lo32/hi32 halves individually.
+ */
+ .macro le64sym, sym
+ .long \sym\()_lo32
+ .long \sym\()_hi32
+ .endm
+
+.globl _start
+_start:
+ /*
+ * DO NOT MODIFY. Image header expected by Linux boot-loaders.
+ */
+ b reset /* branch to kernel start, magic */
+ .long 0 /* reserved */
+ le64sym _kernel_offset_le /* Image load offset from start of RAM, little-endian */
+ le64sym _kernel_size_le /* Effective size of kernel image, little-endian */
+ le64sym _kernel_flags_le /* Informative flags, little-endian */
+ .quad 0 /* reserved */
+ .quad 0 /* reserved */
+ .quad 0 /* reserved */
+ .ascii "ARM\x64" /* Magic number */
+ .long 0 /* reserved */