From ArmadeusWiki
APF6 eMMC layout
By default, the 4GB eMMC on APF6 board has 4 physical/hardware partitions:
Boot0
| Boot1
| RPMB
| User Data
|
Name | U-Boot name | Size | Comment
|
boot0 | mmc dev 0 1 | 2MBytes | U-Boot is installed on this partition
|
boot1 | mmc dev 0 2 | 2MBytes | Not used
|
rpmb | mmc dev 0 3 | 512KBytes | Not used
|
User Data | mmc dev 0 0 | remaining space | Kernel, device tree and rootfs
|
Boot0 partition layout
.
| SPL
| IMG
| ...
| ENV1
| ...
| ENV2
| ...
|
- Linux device: /dev/mmcblk2boot0
Offset (blocks) | Offset (bytes) | Size (bytes) | Comment
|
0 | 0 | 1 KB (0x400) | Free
|
0x02 | 1 KB (0x400) | 68 KB | U-Boot SPL (apf6-u-boot.spl)
|
0x8a | 69 KB (0x11400) | 512 KB | U-Boot IMG (apf6-u-boot.img)
|
| | | Free
|
0x800 (2048) | 1024 KB (0x100000) | 10 KB (0x2800) | U-Boot environment
|
| | | Free
|
0xc00 (3072) | 1536 KB (0x180000) | 10 KB (0x2800) | Redundant U-Boot environment
|
| | | Free
|
User Data partition layout
There are two primary partitions on the "User Data" physical partition:
Name | U-Boot device | Linux device | Offset (bytes) | Offset (blocks) | Size | Comment
|
MBR | NA | NA | 0 | 0 | 512 bytes (1 block) | Master Boot Record. (Don't touch it :-) )
|
... | NA | NA | 512 | 1 | ~1 MBytes (2047 blocks) | Free
|
Boot | mmc 0:1 | /dev/mmcblk2p1 | 1M (0x100000) | 2048 (0x800) | 48 MBytes (98304 blocks) | The kernel and the device tree (inside a dtbs/ directory) are on this partition (ext4 formatted)
|
Rootfs | mmc 0:2 | /dev/mmcblk2p2 | 49M (0x3100000) | 100352 (0x18800) | Rest of space (< 7632896 blocks) | the rootfs is on this partition (ext4 formatted)
|
- By default, when flashed from U-Boot, rootfs and boot are only occupying the size of the .ext4 images used during flashing. If you want to increase the rootfs/boot size to all available free space then, after Linux has booted, use the following commands:
# resize2fs /dev/mmcblk2p1 # for Boot
# resize2fs /dev/mmcblk2p2 # for Rootfs
Rootfs/Boot will then be extended to all the "Rootfs"/"Boot" eMMC partitions space.
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