sunxi: Store the device tree name in the SPL header

This patch updates the mksunxiboot tool to optionally add
the default device tree name string to the SPL header. This
information can be used by the firmware upgrade tools to
protect users from harming themselves by trying to upgrade
to an incompatible bootloader.

The primary use case here is a non-removable bootable media
(such as NAND, eMMC or SPI flash), which already may have
a properly working, but a little bit outdated bootloader
installed. For example, the user may download or build a
new U-Boot image for "Cubieboard", and then attemept to
install it on a "Cubieboard2" hardware by mistake as a
replacement for the already existing bootloader. If this
happens, the flash programming tool can identify this
problem and warn the user.

The size of the SPL header is also increased from 64 bytes
to 96 bytes to provide enough space for the device tree name
string.
[Andre: split patch to remove OF_LIST hash feature]

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

1 files changed, 16 insertions, 3 deletions

diff --git a/arch/arm/include/asm/arch-sunxi/spl.h b/arch/arm/include/asm/arch-sunxi/spl.h
index 831d0c0..9358397 100644
--- a/arch/arm/include/asm/arch-sunxi/spl.h
+++ b/arch/arm/include/asm/arch-sunxi/spl.h
@@ -10,7 +10,7 @@
 
 #define BOOT0_MAGIC		"eGON.BT0"
 #define SPL_SIGNATURE		"SPL" /* marks "sunxi" SPL header */
-#define SPL_HEADER_VERSION	1
+#define SPL_HEADER_VERSION	2
 
 #ifdef CONFIG_SUNXI_HIGH_SRAM
 #define SPL_ADDR		0x10000
@@ -58,11 +58,24 @@ struct boot_file_head {
 	 * compatible format, ready to be imported via "env import -t".
 	 */
 	uint32_t fel_uEnv_length;
-	uint32_t reserved1[2];
+	/*
+	 * Offset of an ASCIIZ string (relative to the SPL header), which
+	 * contains the default device tree name (CONFIG_DEFAULT_DEVICE_TREE).
+	 * This is optional and may be set to NULL. Is intended to be used
+	 * by flash programming tools for providing nice informative messages
+	 * to the users.
+	 */
+	uint32_t dt_name_offset;
+	uint32_t reserved1;
 	uint32_t boot_media;		/* written here by the boot ROM */
-	uint32_t reserved2[5];		/* padding, align to 64 bytes */
+	/* A padding area (may be used for storing text strings) */
+	uint32_t string_pool[13];
+	/* The header must be a multiple of 32 bytes (for VBAR alignment) */
 };
 
+/* Compile time check to assure proper alignment of structure */
+typedef char boot_file_head_not_multiple_of_32[1 - 2*(sizeof(struct boot_file_head) % 32)];
+
 #define is_boot0_magic(addr)	(memcmp((void *)addr, BOOT0_MAGIC, 8) == 0)
 
 #endif