1 files changed, 67 insertions, 0 deletions
diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h
new file mode 100644
index 000000000..7bc3ba897
--- /dev/null
+++ b/arch/arm64/kernel/image.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Linker script macros to generate Image header fields.
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ */
+#ifndef __ARM64_KERNEL_IMAGE_H
+#define __ARM64_KERNEL_IMAGE_H
+
+#ifndef LINKER_SCRIPT
+#error This file should only be included in vmlinux.lds.S
+#endif
+
+#include <asm/image.h>
+
+/*
+ * 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 __HEAD_FLAG(field)	(__HEAD_FLAG_##field << \
+					ARM64_IMAGE_FLAG_##field##_SHIFT)
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define __HEAD_FLAG_BE		ARM64_IMAGE_FLAG_BE
+#else
+#define __HEAD_FLAG_BE		ARM64_IMAGE_FLAG_LE
+#endif
+
+#define __HEAD_FLAG_PAGE_SIZE	((PAGE_SHIFT - 10) / 2)
+
+#define __HEAD_FLAG_PHYS_BASE	1
+
+#define __HEAD_FLAGS		(__HEAD_FLAG(BE)	| \
+				 __HEAD_FLAG(PAGE_SIZE) | \
+				 __HEAD_FLAG(PHYS_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, _end - _text);	\
+	DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS);
+
+#endif /* __ARM64_KERNEL_IMAGE_H */