|
@@ -9,8 +9,8 @@ executes upon reset is the Rom Boot Loader(RBL) which sits in the
|
|
internal ROM of the omap. The RBL initialises the memory and the nand
|
|
internal ROM of the omap. The RBL initialises the memory and the nand
|
|
controller, and copies the image stored at a predefined location(block
|
|
controller, and copies the image stored at a predefined location(block
|
|
1) of the nand flash. The image loaded by the RBL to the memory is the
|
|
1) of the nand flash. The image loaded by the RBL to the memory is the
|
|
-AIS signed nand_spl image. This, in turns copies the u-boot binary
|
|
|
|
-from the nand flash to the memory and jumps to the u-boot entry point.
|
|
|
|
|
|
+AIS signed spl image. This, in turns copies the u-boot binary from the
|
|
|
|
+nand flash to the memory and jumps to the u-boot entry point.
|
|
|
|
|
|
AIS is an image format defined by TI for the images that are to be
|
|
AIS is an image format defined by TI for the images that are to be
|
|
loaded to memory by the RBL. The image is divided into a series of
|
|
loaded to memory by the RBL. The image is divided into a series of
|
|
@@ -20,14 +20,14 @@ and the size of the section, which is used by the RBL to load the
|
|
image. At the end of the image the RBL jumps to the image entry
|
|
image. At the end of the image the RBL jumps to the image entry
|
|
point.
|
|
point.
|
|
|
|
|
|
-The secondary stage bootloader(nand_spl) which is loaded by the RBL
|
|
|
|
-then loads the u-boot from a predefined location in the nand to the
|
|
|
|
-memory and jumps to the u-boot entry point.
|
|
|
|
|
|
+The secondary stage bootloader(spl) which is loaded by the RBL then
|
|
|
|
+loads the u-boot from a predefined location in the nand to the memory
|
|
|
|
+and jumps to the u-boot entry point.
|
|
|
|
|
|
The reason a secondary stage bootloader is used is because the ECC
|
|
The reason a secondary stage bootloader is used is because the ECC
|
|
layout expected by the RBL is not the same as that used by
|
|
layout expected by the RBL is not the same as that used by
|
|
-u-boot/linux. This also implies that for flashing the nand_spl image,
|
|
|
|
-we need to use the u-boot which uses the ECC layout expected by the
|
|
|
|
|
|
+u-boot/linux. This also implies that for flashing the spl image,we
|
|
|
|
+need to use the u-boot which uses the ECC layout expected by the
|
|
RBL[1]. Booting u-boot over UART(UART boot) is explained here[2].
|
|
RBL[1]. Booting u-boot over UART(UART boot) is explained here[2].
|
|
|
|
|
|
|
|
|
|
@@ -35,20 +35,19 @@ Compilation
|
|
===========
|
|
===========
|
|
Three images might be needed
|
|
Three images might be needed
|
|
|
|
|
|
-* nand_spl - This is the secondary bootloader which boots the u-boot
|
|
|
|
|
|
+* spl - This is the secondary bootloader which boots the u-boot
|
|
binary.
|
|
binary.
|
|
|
|
|
|
- hawkboard_nand_config
|
|
|
|
-
|
|
|
|
- The nand_spl ELF gets generated under nand_spl/u-boot-spl. This
|
|
|
|
- needs to be processed with the AISGen tool for generating the AIS
|
|
|
|
- signed image to be flashed. Steps for generating the AIS image are
|
|
|
|
- explained here[3].
|
|
|
|
-
|
|
|
|
* u-boot binary - This is the image flashed to the nand and copied to
|
|
* u-boot binary - This is the image flashed to the nand and copied to
|
|
- the memory by the nand_spl.
|
|
|
|
|
|
+ the memory by the spl.
|
|
|
|
+
|
|
|
|
+ Both the images get compiled with hawkboard_config, with the TOPDIR
|
|
|
|
+ containing the u-boot images, and the spl image under the spl
|
|
|
|
+ directory.
|
|
|
|
|
|
- hawkboard_config
|
|
|
|
|
|
+ The spl image needs to be processed with the AISGen tool for
|
|
|
|
+ generating the AIS signed image to be flashed. Steps for generating
|
|
|
|
+ the AIS image are explained here[3].
|
|
|
|
|
|
* u-boot for uart boot - This is same as the u-boot binary generated
|
|
* u-boot for uart boot - This is same as the u-boot binary generated
|
|
above, with the sole difference of the CONFIG_SYS_TEXT_BASE being
|
|
above, with the sole difference of the CONFIG_SYS_TEXT_BASE being
|
|
@@ -59,17 +58,17 @@ Three images might be needed
|
|
|
|
|
|
Flashing the images to Nand
|
|
Flashing the images to Nand
|
|
===========================
|
|
===========================
|
|
-The nand_spl AIS image needs to be flashed to the block 1 of the
|
|
|
|
-Nand flash, as that is the location the RBL expects the image[4]. For
|
|
|
|
-flashing the nand_spl, boot over the u-boot specified in [1], and
|
|
|
|
-flash the image
|
|
|
|
|
|
+The spl AIS image needs to be flashed to the block 1 of the Nand
|
|
|
|
+flash, as that is the location the RBL expects the image[4]. For
|
|
|
|
+flashing the spl, boot over the u-boot specified in [1], and flash the
|
|
|
|
+image
|
|
|
|
|
|
=> tftpboot 0xc0700000 <nand_spl_ais.bin>
|
|
=> tftpboot 0xc0700000 <nand_spl_ais.bin>
|
|
=> nand erase 0x20000 0x20000
|
|
=> nand erase 0x20000 0x20000
|
|
=> nand write.e 0xc0700000 0x20000 <nand_spl_size>
|
|
=> nand write.e 0xc0700000 0x20000 <nand_spl_size>
|
|
|
|
|
|
The u-boot binary is flashed at location 0xe0000(block 6) of the nand
|
|
The u-boot binary is flashed at location 0xe0000(block 6) of the nand
|
|
-flash. The nand_spl loader expects the u-boot at this location. For
|
|
|
|
|
|
+flash. The spl loader expects the u-boot at this location. For
|
|
flashing the u-boot binary
|
|
flashing the u-boot binary
|
|
|
|
|
|
=> tftpboot 0xc0700000 u-boot.bin
|
|
=> tftpboot 0xc0700000 u-boot.bin
|