[U-Boot] [PATCH v2 2/4] cmd_bootm.c: Add 'booti' for ARM64 Linux kernel Images

[Tom Rini]

The default format for arm64 Linux kernels is the "Image" format,
described in Documentation/arm64/booting.txt.  This, along with an
optional gzip compression on top is all that is generated by default.
The Image format has a magic number within the header for verification,
a text_offset where the Image must be run from, an image_size that
includes the BSS and reserved fields.

This does not support automatic detection of a gzip compressed image.

Signed-off-by: Tom Rini <trini at ti.com>

---
Changes in v1:
- Adopt to Mark Rutland's changes now in mainline kernel wrt text_offset
  / image_size
---
 README             |    1 +
 common/cmd_bootm.c |  140 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/bootm.h    |    2 +-
 3 files changed, 142 insertions(+), 1 deletion(-)

diff --git a/README b/README
index 1d71359..b9af7ac 100644
--- a/README
+++ b/README
@@ -959,6 +959,7 @@ The following options need to be configured:
 		CONFIG_CMD_BMP		* BMP support
 		CONFIG_CMD_BSP		* Board specific commands
 		CONFIG_CMD_BOOTD	  bootd
+		CONFIG_CMD_BOOTI	* ARM64 Linux kernel Image support
 		CONFIG_CMD_CACHE	* icache, dcache
 		CONFIG_CMD_CLK   	* clock command support
 		CONFIG_CMD_CONSOLE	  coninfo
diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index 8b897c8d..843ec6e 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -627,3 +627,143 @@ U_BOOT_CMD(
 	"boot Linux zImage image from memory", bootz_help_text
 );
 #endif	/* CONFIG_CMD_BOOTZ */
+
+#ifdef CONFIG_CMD_BOOTI
+/* See Documentation/arm64/booting.txt in the Linux kernel */
+struct Image_header {
+	uint32_t	code0;		/* Executable code */
+	uint32_t	code1;		/* Executable code */
+	uint64_t	text_offset;	/* Image load offset, LE */
+	uint64_t	image_size;	/* Effective Image size, LE */
+	uint64_t	res1;		/* reserved */
+	uint64_t	res2;		/* reserved */
+	uint64_t	res3;		/* reserved */
+	uint64_t	res4;		/* reserved */
+	uint32_t	magic;		/* Magic number */
+	uint32_t	res5;
+};
+
+#define LINUX_ARM64_IMAGE_MAGIC	0x644d5241
+
+static int booti_setup(bootm_headers_t *images)
+{
+	struct Image_header *ih;
+	uint64_t dst;
+
+	ih = (struct Image_header *)map_sysmem(images->ep, 0);
+
+	if (ih->magic != le32_to_cpu(LINUX_ARM64_IMAGE_MAGIC)) {
+		puts("Bad Linux ARM64 Image magic!\n");
+		return 1;
+	}
+	
+	if (ih->image_size == 0) {
+		puts("Image lacks image_size field, assuming 16MiB\n");
+		ih->image_size = (16 << 20);
+	}
+
+	/*
+	 * If we are not at the correct run-time location, set the new
+	 * correct location and then move the image there.
+	 */
+	dst = gd->bd->bi_dram[0].start + le32_to_cpu(ih->text_offset);
+	if (images->ep != dst) {
+		void *src;
+
+		debug("Moving Image from 0x%lx to 0x%llx\n", images->ep, dst);
+
+		src = (void *)images->ep;
+		images->ep = dst;
+		memmove((void *)dst, src, le32_to_cpu(ih->image_size));
+	}
+
+	return 0;
+}
+
+/*
+ * Image booting support
+ */
+static int booti_start(cmd_tbl_t *cmdtp, int flag, int argc,
+			char * const argv[], bootm_headers_t *images)
+{
+	int ret;
+	struct Image_header *ih;
+
+	ret = do_bootm_states(cmdtp, flag, argc, argv, BOOTM_STATE_START,
+			      images, 1);
+
+	/* Setup Linux kernel Image entry point */
+	if (!argc) {
+		images->ep = load_addr;
+		debug("*  kernel: default image load address = 0x%08lx\n",
+				load_addr);
+	} else {
+		images->ep = simple_strtoul(argv[0], NULL, 16);
+		debug("*  kernel: cmdline image address = 0x%08lx\n",
+			images->ep);
+	}
+
+	ret = booti_setup(images);
+	if (ret != 0)
+		return 1;
+
+	ih = (struct Image_header *)map_sysmem(images->ep, 0);
+
+	lmb_reserve(&images->lmb, images->ep, le32_to_cpu(ih->image_size));
+
+	/*
+	 * Handle the BOOTM_STATE_FINDOTHER state ourselves as we do not
+	 * have a header that provide this informaiton.
+	 */
+	if (bootm_find_ramdisk_fdt(flag, argc, argv))
+		return 1;
+
+	return 0;
+}
+
+int do_booti(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	int ret;
+
+	/* Consume 'booti' */
+	argc--; argv++;
+
+	if (booti_start(cmdtp, flag, argc, argv, &images))
+		return 1;
+
+	/*
+	 * We are doing the BOOTM_STATE_LOADOS state ourselves, so must
+	 * disable interrupts ourselves
+	 */
+	bootm_disable_interrupts();
+
+	images.os.os = IH_OS_LINUX;
+	ret = do_bootm_states(cmdtp, flag, argc, argv,
+			      BOOTM_STATE_OS_PREP | BOOTM_STATE_OS_FAKE_GO |
+			      BOOTM_STATE_OS_GO,
+			      &images, 1);
+
+	return ret;
+}
+
+#ifdef CONFIG_SYS_LONGHELP
+static char booti_help_text[] =
+	"[addr [initrd[:size]] [fdt]]\n"
+	"    - boot Linux Image stored in memory\n"
+	"\tThe argument 'initrd' is optional and specifies the address\n"
+	"\tof the initrd in memory. The optional argument ':size' allows\n"
+	"\tspecifying the size of RAW initrd.\n"
+#if defined(CONFIG_OF_LIBFDT)
+	"\tSince booting a Linux kernelrequires a flat device-tree\n"
+	"\ta third argument is required which is the address of the\n"
+	"\tdevice-tree blob. To boot that kernel without an initrd image,\n"
+	"\tuse a '-' for the second argument.\n"
+#endif
+	"";
+#endif
+
+U_BOOT_CMD(
+	booti,	CONFIG_SYS_MAXARGS,	1,	do_booti,
+	"boot arm64 Linux Image image from memory", booti_help_text
+);
+#endif	/* CONFIG_CMD_BOOTI */
diff --git a/include/bootm.h b/include/bootm.h
index 4a308d8..694d6fc 100644
--- a/include/bootm.h
+++ b/include/bootm.h
@@ -48,7 +48,7 @@ int boot_selected_os(int argc, char * const argv[], int state,
 
 ulong bootm_disable_interrupts(void);
 
-/* This is a special function used by bootz */
+/* This is a special function used by booti/bootz */
 int bootm_find_ramdisk_fdt(int flag, int argc, char * const argv[]);
 
 int do_bootm_states(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
-- 
1.7.9.5