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| author | Bernhard Nortmann <bernhard.nortmann@web.de> | 2015-09-17 18:52:51 +0200 |
|---|---|---|
| committer | Hans de Goede <hdegoede@redhat.com> | 2015-09-29 11:50:07 +0200 |
| commit | a188438175bd5fb4ef0440c9fdd0ded8b5640b3d (patch) | |
| tree | c30231ef3e1e183e913ec6a17300f25f68f0e724 /arch | |
| parent | e954eb8028d7085fc8d0737c8e637ab940f7f147 (diff) | |
sunxi: (mksunxiboot) signature to indicate "sunxi" SPL variant
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>
Acked-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/include/asm/arch-sunxi/spl.h | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/arm/include/asm/arch-sunxi/spl.h b/arch/arm/include/asm/arch-sunxi/spl.h index 5bcd0ebbd0..d2ce848455 100644 --- a/arch/arm/include/asm/arch-sunxi/spl.h +++ b/arch/arm/include/asm/arch-sunxi/spl.h @@ -9,6 +9,8 @@ #define _ASM_ARCH_SPL_H_ #define BOOT0_MAGIC "eGON.BT0" +#define SPL_SIGNATURE "SPL" /* marks "sunxi" SPL header */ +#define SPL_HEADER_VERSION 1 /* boot head definition from sun4i boot code */ struct boot_file_head { @@ -21,8 +23,23 @@ 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 */ }; #endif |