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author | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-23 03:29:33 +0200 |
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committer | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-23 03:29:33 +0200 |
commit | 15dfd0df63ce6847081d09b2bbd567cc0cc4eae1 (patch) | |
tree | 3b73f24fcef970bfcace3cbb297cfa57f3994682 /Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt | |
parent | 328aa7a45af61bc0060c80847daa67fef7b9c0d0 (diff) | |
parent | 0149138c4142da287d23f9d5c6038f7fb5e30ac2 (diff) | |
download | kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.zip kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.tar.gz kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.tar.bz2 |
initial merge with 3.2.72
Diffstat (limited to 'Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt')
-rw-r--r-- | Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt b/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt new file mode 100644 index 0000000..4419598 --- /dev/null +++ b/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt @@ -0,0 +1,42 @@ +ROM-able zImage boot from eSD +----------------------------- + +An ROM-able zImage compiled with ZBOOT_ROM_SDHI may be written to eSD and +SuperH Mobile ARM will to boot directly from the SDHI hardware block. + +This is achieved by the mask ROM loading the first portion of the image into +MERAM and then jumping to it. This portion contains loader code which +copies the entire image to SDRAM and jumps to it. From there the zImage +boot code proceeds as normal, uncompressing the image into its final +location and then jumping to it. + +This code has been tested on an mackerel board using the developer 1A eSD +boot mode which is configured using the following jumper settings. + + 8 7 6 5 4 3 2 1 + x|x|x|x| |x|x| +S4 -+-+-+-+-+-+-+- + | | | |x| | |x on + +The eSD card needs to be present in SDHI slot 1 (CN7). +As such S1 and S33 also need to be configured as per +the notes in arch/arm/mach-shmobile/board-mackerel.c. + +A partial zImage must be written to physical partition #1 (boot) +of the eSD at sector 0 in vrl4 format. A utility vrl4 is supplied to +accomplish this. + +e.g. + vrl4 < zImage | dd of=/dev/sdX bs=512 count=17 + +A full copy of _the same_ zImage should be written to physical partition #1 +(boot) of the eSD at sector 0. This should _not_ be in vrl4 format. + + vrl4 < zImage | dd of=/dev/sdX bs=512 + +Note: The commands above assume that the physical partition has been +switched. No such facility currently exists in the Linux Kernel. + +Physical partitions are described in the eSD specification. At the time of +writing they are not the same as partitions that are typically configured +using fdisk and visible through /proc/partitions |