RISCV: image: Add booti support

This patch adds booti support for RISC-V Linux kernel. The existing
bootm method will also continue to work as it is.

It depends on the following kernel patch which adds the header to the
flat Image. Gzip compressed Image (Image.gz) support is not enabled with
this patch.

https://patchwork.kernel.org/patch/10925543/

Tested on HiFive Unleashed and QEMU.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Tested-by: Karsten Merker <merker@debian.org>
Reviewed-by: Marek Vasut <marek.vasut@gmail.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/arch/riscv/lib/image.c b/arch/riscv/lib/image.c
new file mode 100644
index 0000000000..d063beb7df
--- /dev/null
+++ b/arch/riscv/lib/image.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
+ * Authors:
+ *	Atish Patra <atish.patra@wdc.com>
+ * Based on arm/lib/image.c
+ */
+
+#include <common.h>
+#include <mapmem.h>
+#include <errno.h>
+#include <linux/sizes.h>
+#include <linux/stddef.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* ASCII version of "RISCV" defined in Linux kernel */
+#define LINUX_RISCV_IMAGE_MAGIC 0x5643534952
+
+struct linux_image_h {
+	uint32_t	code0;		/* Executable code */
+	uint32_t	code1;		/* Executable code */
+	uint64_t	text_offset;	/* Image load offset */
+	uint64_t	image_size;	/* Effective Image size */
+	uint64_t	res1;		/* reserved */
+	uint64_t	res2;		/* reserved */
+	uint64_t	res3;		/* reserved */
+	uint64_t	magic;		/* Magic number */
+	uint32_t	res4;		/* reserved */
+	uint32_t	res5;		/* reserved */
+};
+
+int booti_setup(ulong image, ulong *relocated_addr, ulong *size,
+		bool force_reloc)
+{
+	struct linux_image_h *lhdr;
+
+	lhdr = (struct linux_image_h *)map_sysmem(image, 0);
+
+	if (lhdr->magic != LINUX_RISCV_IMAGE_MAGIC) {
+		puts("Bad Linux RISCV Image magic!\n");
+		return -EINVAL;
+	}
+
+	if (lhdr->image_size == 0) {
+		puts("Image lacks image_size field, error!\n");
+		return -EINVAL;
+	}
+	*size = lhdr->image_size;
+	*relocated_addr = gd->ram_base + lhdr->text_offset;
+
+	unmap_sysmem(lhdr);
+
+	return 0;
+}