mirror of
https://github.com/u-boot/u-boot.git
synced 2025-04-16 01:44:34 +00:00
![]() Modern eMMC v4+ devices have multiple hardware partitions per the JEDEC specification described as: Boot Area Partition 1 Boot Area Partition 2 RPMB Partition General Purpose Partition 1 General Purpose Partition 2 General Purpose Partition 3 General Purpose Partition 4 User Data Area These are referenced by fields in the PARTITION_CONFIG register (Extended CSD Register 179) which is defined as: bit 7: reserved bit 6: BOOT_ACK 0x0: No boot acknowledge sent (default 0x1: Boot acknowledge sent during boot operation Bit bit 5:3: BOOT_PARTITION_ENABLE 0x0: Device not boot enabled (default) 0x1: Boot Area partition 1 enabled for boot 0x2: Boot Area partition 2 enabled for boot 0x3-0x6: Reserved 0x7: User area enabled for boot bit 2:0 PARTITION_ACCESS 0x0: No access to boot partition (default) 0x1: Boot Area partition 1 0x2: Boot Area partition 2 0x3: Replay Protected Memory Block (RPMB) 0x4: Access to General Purpose partition 1 0x5: Access to General Purpose partition 2 0x6: Access to General Purpose partition 3 0x7: Access to General Purpose partition 4 Note that setting PARTITION_ACCESS to 0x0 results in selecting the User Data Area partition. You can see above that the two fields BOOT_PARTITION_ENABLE and PARTITION_ACCESS do not use the same enumerated values. U-Boot uses a set of macros to access fields of the PARTITION_CONFIG register: There are various places in U-Boot where the BOOT_PARTITION_ENABLE field is accessed via EXT_CSD_EXTRACT_PARTITION_ACCESS and converted to a hardware partition consistent with the definition of the PARTITION_ACCESS field which is also the value used to specify the hardware partition of the various mmc_switch incarnations. To add some sanity to the distinction between BOOT_PARTITION_ENABLE (used to specify the active device on power-cycle) and PARTITION_ACCESS (used to switch between hardware partitions) create two enumerated types and use them wherever struct mmc * part_config is used or the above macros are used. This represents no code changes. Signed-off-by: Tim Harvey <tharvey@gateworks.com> |
||
---|---|---|
.. | ||
gw_ventana | ||
venice |