MobileRead Forums - View Single Post - Compiling the Linux Kernel for the Kindle

newman · 08-29-2015, 06:08 PM

Am I right that

2/DX uses MTD for U-Boot (regular and backup), kernel (regular and backup), ... but
K3 uses just the first sectors of MMC (moviNAND) for one bootloader and one kernel
so 2/DX with 3.x FW has to use some smart combination of both (e.g. booting from MTD but letting official update scripts to flash the 3.x kernel to a place where it can't anything bad, i.e. beginning of MMC)?

(See the rest of the post why I think so.)

FW 3.4 [moviNAND]

Luigi-based moviNAND device partition scheme:

Code:

MOVINAND_DEVICE=/dev/mmcblk0
MOVINAND_OFFSET_PARTITION=0     #0x00000000 Partition Map
MOVINAND_OFFSET_HEADER=1024     #0x00000400 DCD Header
MOVINAND_OFFSET_U_BOOT=3072     #0x00000C00 Boot Loader                       
MOVINAND_OFFSET_KERNEL=266240   #0x00041000 Linux Kernel
MOVINAND_OFFSET_ISISWF=3674112  #0x00381000 ISIS Waveform
MOVINAND_OFFSET_ROOTFS=3936256  #0x003C1000 Root filesystem

Code:

BLOCK_SIZE=1024
KERNEL_OFFSET=266,240
KERNEL_SEEK=$(( ${KERNEL_OFFSET} / ${BLOCK_SIZE} )) = 260 blocks
$ dd if=${KERNEL_FILE} of=/dev/mmcblk0 seek=${KERNEL_SEEK} bs=${BLOCK_SIZE}
`--------------------------------------^^^^--skip KERNEL_SEEK blocks (260 blocks * 512 B = 133,120 B)

3.{3,4} uImage kernel size = 2,1 MB (64 B header)

Looking at mine mmcblk0, there's no U-Boot, just an empty place to be filled eventually (see the partition scheme)

FW 2.5.8 [MTD]

what I have on DXi in /dev/mtdblock{1,4} is a YifanaLu's kernel (verified by dd-ing it out by md5sum)
in /dev/mtblock{0,3} is U-Boot from 2.5.8 (i.e. the original one) (verified by dd-ing it out by md5sum)

/proc/mtd:

Code:

dev:    size   erasesize  name
mtd0: 00020000 00010000 "Bootloader1"
mtd1: 00380000 00010000 "Kernel1"
mtd2: 00008000 00002000 "BoardId"
mtd3: 00020000 00010000 "Bootloader2"
mtd4: 00380000 00010000 "Kernel2"
mtd5: 00010000 00010000 "BootEnv"
mtd6: 00020000 00010000 "Diags"
mtd7: 00006000 00002000 "Vectors"
mtd8: 00010000 00010000 "unused0"

MTD needs to be unlocked before erase→flash

Code:

flash_unlock /dev/mtd/0..1..3..4

From 2.5.8 FW update; how to flash U-Boot and kernel, both regular and backup ones:

size of u-boot.bin = 131,072 B

Code:

$ dd if=imx31_mario/u-boot.bin of=/dev/mtdblock/0 bs=131072
$ dd if=imx31_mario/u-boot.bin of=/dev/mtdblock/3 bs=131072

size of uImage = 1,875,952 B

Code:

$ dd if=uImage of=/dev/mtdblock/1 bs=131072
$ dd if=uImage of=/dev/mtdblock/4 bs=131072

08-29-2015, 06:08 PM	#70
newman homo viator Posts: 78 Karma: 252594 Join Date: May 2010 Device: Kindle DXi with 3.4.2 firmware, Kobo Glo HD	Am I right that 2/DX uses MTD for U-Boot (regular and backup), kernel (regular and backup), ... but K3 uses just the first sectors of MMC (moviNAND) for one bootloader and one kernel so 2/DX with 3.x FW has to use some smart combination of both (e.g. booting from MTD but letting official update scripts to flash the 3.x kernel to a place where it can't anything bad, i.e. beginning of MMC)? (See the rest of the post why I think so.) FW 3.4 [moviNAND] Luigi-based moviNAND device partition scheme: Code: MOVINAND_DEVICE=/dev/mmcblk0 MOVINAND_OFFSET_PARTITION=0 #0x00000000 Partition Map MOVINAND_OFFSET_HEADER=1024 #0x00000400 DCD Header MOVINAND_OFFSET_U_BOOT=3072 #0x00000C00 Boot Loader MOVINAND_OFFSET_KERNEL=266240 #0x00041000 Linux Kernel MOVINAND_OFFSET_ISISWF=3674112 #0x00381000 ISIS Waveform MOVINAND_OFFSET_ROOTFS=3936256 #0x003C1000 Root filesystem Code: BLOCK_SIZE=1024 KERNEL_OFFSET=266,240 KERNEL_SEEK=$(( ${KERNEL_OFFSET} / ${BLOCK_SIZE} )) = 260 blocks $ dd if=${KERNEL_FILE} of=/dev/mmcblk0 seek=${KERNEL_SEEK} bs=${BLOCK_SIZE} `--------------------------------------^^^^--skip KERNEL_SEEK blocks (260 blocks * 512 B = 133,120 B) 3.{3,4} uImage kernel size = 2,1 MB (64 B header) Looking at mine mmcblk0, there's no U-Boot, just an empty place to be filled eventually (see the partition scheme) FW 2.5.8 [MTD] what I have on DXi in /dev/mtdblock{1,4} is a YifanaLu's kernel (verified by dd-ing it out by md5sum) in /dev/mtblock{0,3} is U-Boot from 2.5.8 (i.e. the original one) (verified by dd-ing it out by md5sum) /proc/mtd: Code: dev: size erasesize name mtd0: 00020000 00010000 "Bootloader1" mtd1: 00380000 00010000 "Kernel1" mtd2: 00008000 00002000 "BoardId" mtd3: 00020000 00010000 "Bootloader2" mtd4: 00380000 00010000 "Kernel2" mtd5: 00010000 00010000 "BootEnv" mtd6: 00020000 00010000 "Diags" mtd7: 00006000 00002000 "Vectors" mtd8: 00010000 00010000 "unused0" MTD needs to be unlocked before erase→flash Code: flash_unlock /dev/mtd/0..1..3..4 From 2.5.8 FW update; how to flash U-Boot and kernel, both regular and backup ones: size of u-boot.bin = 131,072 B Code: $ dd if=imx31_mario/u-boot.bin of=/dev/mtdblock/0 bs=131072 $ dd if=imx31_mario/u-boot.bin of=/dev/mtdblock/3 bs=131072 size of uImage = 1,875,952 B Code: $ dd if=uImage of=/dev/mtdblock/1 bs=131072 $ dd if=uImage of=/dev/mtdblock/4 bs=131072