Hi Tom,
On Thu, Aug 14, 2014 at 11:42:36AM +0100, Tom Rini wrote:
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@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 supportdiff --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);- }
This should work for a defconfig, but it might be possible to build a larger kernel. From experiments with an allyesconfig, I can build a ~60MB kernel with ~20MB of uninitialised data after the end of the Image.
Modifying the Image feels a little dodgy, but I can't think of anything this would break.
- /*
* 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);
This should be le64_to_cpu(ih->text_offset) to be strictly correct.
I wouldn't imagine we'd ever have a text_offset larger than 4GB, but it would be nice to keep things consistent with the documentation and kernel code.
- 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));
Likewise.
- }
- 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));
Likewise.
[...]
+#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"
Nit: space between "kernel" and "requires"
Thanks, Mark.