[U-Boot] [PATCH] sunxi: Increase the SPL header size to 48 bytes to avoid code corruption
The current SPL header, created by the 'mksunxiboot' tool, has size 32 bytes. But the code in the boot ROM stores the information about the boot media at the offset 0x28 before passing control to the SPL. For example, when booting from the SD card, the magic number written by the boot ROM is 0. And when booting from the SPI flash, the magic number is 3. NAND and eMMC probably have their own special magic numbers too.
Currently the corrupted byte is a part of one of the instructions in the reset vectors table:
b reset ldr pc, _undefined_instruction ldr pc, _software_interrupt <- Corruption happens here ldr pc, _prefetch_abort ldr pc, _data_abort ldr pc, _not_used ldr pc, _irq ldr pc, _fiq
In practice this does not cause any visible problems, but it's still better to fix it. As a bonus, the reported boot media type can be later used in the 'spl_boot_device' function, but this is out of the scope of this patch.
Signed-off-by: Siarhei Siamashka siarhei.siamashka@gmail.com --- arch/arm/include/asm/arch-sunxi/spl.h | 8 +++++++- include/configs/sunxi-common.h | 12 ++++++------ 2 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/arch/arm/include/asm/arch-sunxi/spl.h b/arch/arm/include/asm/arch-sunxi/spl.h index ca9a4f9..80696a8 100644 --- a/arch/arm/include/asm/arch-sunxi/spl.h +++ b/arch/arm/include/asm/arch-sunxi/spl.h @@ -18,6 +18,10 @@ #define SPL_ADDR 0x0 #endif
+/* The low 8-bits of the 'boot_media' field in the SPL header */ +#define SUNXI_BOOTED_FROM_MMC0 0 +#define SUNXI_BOOTED_FROM_SPI 3 + /* boot head definition from sun4i boot code */ struct boot_file_head { uint32_t b_instruction; /* one intruction jumping to real code */ @@ -45,7 +49,9 @@ struct boot_file_head { uint8_t spl_signature[4]; }; uint32_t fel_script_address; - uint32_t reserved; /* padding, align to 32 bytes */ + uint32_t reserved1[3]; + uint32_t boot_media; /* written here by the boot ROM */ + uint32_t reserved2; /* padding, align to 48 bytes */ };
#define is_boot0_magic(addr) (memcmp((void *)addr, BOOT0_MAGIC, 8) == 0) diff --git a/include/configs/sunxi-common.h b/include/configs/sunxi-common.h index 2406115..945ed0a 100644 --- a/include/configs/sunxi-common.h +++ b/include/configs/sunxi-common.h @@ -189,14 +189,14 @@ #define CONFIG_SPL_BOARD_LOAD_IMAGE
#if defined(CONFIG_MACH_SUN9I) -#define CONFIG_SPL_TEXT_BASE 0x10020 /* sram start+header */ -#define CONFIG_SPL_MAX_SIZE 0x5fe0 /* ? KiB on sun9i */ +#define CONFIG_SPL_TEXT_BASE 0x10030 /* sram start+header */ +#define CONFIG_SPL_MAX_SIZE 0x5fd0 /* ? KiB on sun9i */ #elif defined(CONFIG_MACH_SUN50I) -#define CONFIG_SPL_TEXT_BASE 0x10020 /* sram start+header */ -#define CONFIG_SPL_MAX_SIZE 0x7fe0 /* 32 KiB on sun50i */ +#define CONFIG_SPL_TEXT_BASE 0x10030 /* sram start+header */ +#define CONFIG_SPL_MAX_SIZE 0x7fd0 /* 32 KiB on sun50i */ #else -#define CONFIG_SPL_TEXT_BASE 0x20 /* sram start+header */ -#define CONFIG_SPL_MAX_SIZE 0x5fe0 /* 24KB on sun4i/sun7i */ +#define CONFIG_SPL_TEXT_BASE 0x30 /* sram start+header */ +#define CONFIG_SPL_MAX_SIZE 0x5fd0 /* 24KB on sun4i/sun7i */ #endif
#define CONFIG_SPL_LIBDISK_SUPPORT
On Sat, 14 May 2016 03:14:25 +0300 Siarhei Siamashka siarhei.siamashka@gmail.com wrote:
The current SPL header, created by the 'mksunxiboot' tool, has size 32 bytes. But the code in the boot ROM stores the information about the boot media at the offset 0x28 before passing control to the SPL. For example, when booting from the SD card, the magic number written by the boot ROM is 0. And when booting from the SPI flash, the magic number is 3. NAND and eMMC probably have their own special magic numbers too.
Currently the corrupted byte is a part of one of the instructions in the reset vectors table:
b reset ldr pc, _undefined_instruction ldr pc, _software_interrupt <- Corruption happens here ldr pc, _prefetch_abort ldr pc, _data_abort ldr pc, _not_used ldr pc, _irq ldr pc, _fiqIn practice this does not cause any visible problems, but it's still better to fix it. As a bonus, the reported boot media type can be later used in the 'spl_boot_device' function, but this is out of the scope of this patch.
Signed-off-by: Siarhei Siamashka siarhei.siamashka@gmail.com
arch/arm/include/asm/arch-sunxi/spl.h | 8 +++++++- include/configs/sunxi-common.h | 12 ++++++------ 2 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/arch/arm/include/asm/arch-sunxi/spl.h b/arch/arm/include/asm/arch-sunxi/spl.h index ca9a4f9..80696a8 100644 --- a/arch/arm/include/asm/arch-sunxi/spl.h +++ b/arch/arm/include/asm/arch-sunxi/spl.h @@ -18,6 +18,10 @@ #define SPL_ADDR 0x0 #endif
+/* The low 8-bits of the 'boot_media' field in the SPL header */ +#define SUNXI_BOOTED_FROM_MMC0 0 +#define SUNXI_BOOTED_FROM_SPI 3
/* boot head definition from sun4i boot code */ struct boot_file_head { uint32_t b_instruction; /* one intruction jumping to real code */ @@ -45,7 +49,9 @@ struct boot_file_head { uint8_t spl_signature[4]; }; uint32_t fel_script_address;
- uint32_t reserved; /* padding, align to 32 bytes */
- uint32_t reserved1[3];
- uint32_t boot_media; /* written here by the boot ROM */
- uint32_t reserved2; /* padding, align to 48 bytes */
};
#define is_boot0_magic(addr) (memcmp((void *)addr, BOOT0_MAGIC, 8) == 0) diff --git a/include/configs/sunxi-common.h b/include/configs/sunxi-common.h index 2406115..945ed0a 100644 --- a/include/configs/sunxi-common.h +++ b/include/configs/sunxi-common.h @@ -189,14 +189,14 @@ #define CONFIG_SPL_BOARD_LOAD_IMAGE
#if defined(CONFIG_MACH_SUN9I) -#define CONFIG_SPL_TEXT_BASE 0x10020 /* sram start+header */ -#define CONFIG_SPL_MAX_SIZE 0x5fe0 /* ? KiB on sun9i */ +#define CONFIG_SPL_TEXT_BASE 0x10030 /* sram start+header */ +#define CONFIG_SPL_MAX_SIZE 0x5fd0 /* ? KiB on sun9i */ #elif defined(CONFIG_MACH_SUN50I) -#define CONFIG_SPL_TEXT_BASE 0x10020 /* sram start+header */ -#define CONFIG_SPL_MAX_SIZE 0x7fe0 /* 32 KiB on sun50i */ +#define CONFIG_SPL_TEXT_BASE 0x10030 /* sram start+header */ +#define CONFIG_SPL_MAX_SIZE 0x7fd0 /* 32 KiB on sun50i */ #else -#define CONFIG_SPL_TEXT_BASE 0x20 /* sram start+header */ -#define CONFIG_SPL_MAX_SIZE 0x5fe0 /* 24KB on sun4i/sun7i */ +#define CONFIG_SPL_TEXT_BASE 0x30 /* sram start+header */ +#define CONFIG_SPL_MAX_SIZE 0x5fd0 /* 24KB on sun4i/sun7i */ #endif
#define CONFIG_SPL_LIBDISK_SUPPORT
If we are placing the reset vectors table right after the SPL header, then we need a 32-byte alignment. An updated v2 patch submitted (sorry for a different summary line):
https://patchwork.ozlabs.org/patch/622173/
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Siarhei Siamashka