Difference between revisions of "APF6 EMMC"

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(User Data partition layout)
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{| border="1" cellpadding="5" cellspacing="0" summary="APF6 eMMC User data partitions details"
 
{| border="1" cellpadding="5" cellspacing="0" summary="APF6 eMMC User data partitions details"
 
|- style="background:#efefef;" align="center"
 
|- style="background:#efefef;" align="center"
!Name || U-Boot device  || Linux device || Offset (blocks) || Size || Comment
+
!Name || U-Boot device  || Linux device || Offset (bytes) || Offset (blocks) || Size || Comment
 
|----------------
 
|----------------
|MBR || NA || NA || 0 || 512 bytes (1 block) || Master Boot Record. (Don't touch it :-) )
+
|MBR || NA || NA || 0 || 0 || 512 bytes (1 block) || Master Boot Record. (Don't touch it :-) )
 
|----------------
 
|----------------
|... || NA || NA || 1 || ~1 MBytes (2047 blocks) || Free
+
|... || NA || NA || 512 || 1 || ~1 MBytes (2047 blocks) || Free
 
|----------------
 
|----------------
|Boot || mmc 0:1 || /dev/mmcblk2p1 || 2048 (0x800) || 24 MBytes (49152 blocks) || The kernel and the device tree (inside a ''dtbs/'' directory) are on this partition (ext4 formatted)
+
|Boot || mmc 0:1 || /dev/mmcblk2p1 || 1M (0x100000) || 2048 (0x800) || 24 MBytes (49152 blocks) || The kernel and the device tree (inside a ''dtbs/'' directory) are on this partition (ext4 formatted)
 
|----------------
 
|----------------
|Rootfs || mmc 0:2 || /dev/mmcblk2p2 || 51200 (0xc800) || Rest of space (< 7682048 blocks) || the rootfs is on this partition (ext4 formatted)
+
|Rootfs || mmc 0:2 || /dev/mmcblk2p2 || 25M (0x1900000)|| 51200 (0xc800) || Rest of space (< 7682048 blocks) || the rootfs is on this partition (ext4 formatted)
 
|----------------
 
|----------------
 
|}
 
|}

Revision as of 15:27, 31 July 2015

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:

... Boot Rootfs


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) 24 MBytes (49152 blocks) The kernel and the device tree (inside a dtbs/ directory) are on this partition (ext4 formatted)
Rootfs mmc 0:2 /dev/mmcblk2p2 25M (0x1900000) 51200 (0xc800) Rest of space (< 7682048 blocks) the rootfs is on this partition (ext4 formatted)
  • By default rootfs is only occupying the size of the .ext4 image flashed with U-Boot. If you want to increase the rootfs to all available free space then, after Linux has booted, use the following command:
# resize2fs /dev/mmcblk2p2

Rootfs will then be extended to all the "Rootfs" eMMC partition space.

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