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39 lines
1.3 KiB
39 lines
1.3 KiB
Embedded device command line partition parsing |
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Support for reading the block device partition table from the command line. |
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It is typically used for fixed block (eMMC) embedded devices. |
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It has no MBR, so saves storage space. Bootloader can be easily accessed |
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by absolute address of data on the block device. |
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Users can easily change the partition. |
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The format for the command line is just like mtdparts: |
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blkdevparts=<blkdev-def>[;<blkdev-def>] |
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<blkdev-def> := <blkdev-id>:<partdef>[,<partdef>] |
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<partdef> := <size>[@<offset>](part-name) |
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<blkdev-id> |
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block device disk name, embedded device used fixed block device, |
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it's disk name also fixed. such as: mmcblk0, mmcblk1, mmcblk0boot0. |
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<size> |
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partition size, in bytes, such as: 512, 1m, 1G. |
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<offset> |
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partition start address, in bytes. |
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(part-name) |
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partition name, kernel send uevent with "PARTNAME". application can create |
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a link to block device partition with the name "PARTNAME". |
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user space application can access partition by partition name. |
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Example: |
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eMMC disk name is "mmcblk0" and "mmcblk0boot0" |
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bootargs: |
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'blkdevparts=mmcblk0:1G(data0),1G(data1),-;mmcblk0boot0:1m(boot),-(kernel)' |
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dmesg: |
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mmcblk0: p1(data0) p2(data1) p3() |
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mmcblk0boot0: p1(boot) p2(kernel)
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