On Mon, 14 Sep 2015 15:15:28 +0200 Bernhard Nortmann bernhard.nortmann@web.de wrote:
This patch follows up on a discussion of ways to improve support for the sunxi FEL ("USB boot") mechanism, especially with regard to boot scripts, see: https://groups.google.com/d/msg/linux-sunxi/wBEGUoLNRro/rHGq6nSYCQAJ
The idea is to convert the (currently unused) "pad" bytes in the SPL header into an area where data can be passed to U-Boot. To do this safely, we have to make sure that we're actually using our "sunxi" flavor of the SPL, and not the Allwinner boot0.
The modified mksunxiboot introduces a special signature to the SPL header in place of the "pub_head_size" field. This can be used to reliably distinguish between compatible versions of sunxi SPL and anything else (older variants or Allwinner's boot0).
Signed-off-by: Bernhard Nortmann bernhard.nortmann@web.de
Changes in v2:
- Rename field to fel_script_address, discard fel_data_size
- Clearing header fields is no longer needed, as mksunxiboot.c zeroes entire image first
tools/mksunxiboot.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/tools/mksunxiboot.c b/tools/mksunxiboot.c index 676d392..cb0865c 100644 --- a/tools/mksunxiboot.c +++ b/tools/mksunxiboot.c @@ -27,12 +27,29 @@ struct boot_file_head { * by the boot ROM. To be compatible with Allwinner tools we * would need to implement the proper fields here instead of * padding.
** Actually we want the ability to recognize our "sunxi" variant* of the SPL. To do so, let's place a special signature into the* "pub_head_size" field. We can reasonably expect Allwinner's* boot0 to always have the upper 16 bits of this set to 0 (after* all the value shouldn't be larger than the limit imposed by* SRAM size).* If the signature is present (at 0x14), then we know it's safe* to use the remaining 8 bytes (at 0x18) for our own purposes.* (E.g. sunxi-tools "fel" utility can pass information there.)
- uint8_t pad[12]; /* align to 32 bytes */
- union {
uint32_t pub_head_size;uint8_t spl_signature[4];- };
- uint32_t fel_script_address;
- uint32_t reserved; /* padding, align to 32 bytes */
};
#define BOOT0_MAGIC "eGON.BT0" #define STAMP_VALUE 0x5F0A6C39 +#define SPL_SIGNATURE "SPL" /* marks "sunxi" header */ +#define SPL_HEADER_VERSION 1
/* check sum functon from sun4i boot code */ int gen_check_sum(struct boot_file_head *head_p) @@ -133,6 +150,10 @@ int main(int argc, char *argv[]) ALIGN(file_size + sizeof(struct boot_file_head), BLOCK_SIZE); img.header.b_instruction = cpu_to_le32(img.header.b_instruction); img.header.length = cpu_to_le32(img.header.length);
memcpy(img.header.spl_signature, SPL_SIGNATURE, 3); /* "sunxi" marker */
img.header.spl_signature[3] = SPL_HEADER_VERSION;
gen_check_sum(&img.header);
count = write(fd_out, &img, le32_to_cpu(img.header.length));
Acked-by: Siarhei Siamashka siarhei.siamashka@gmail.com