In message 4309712D.1040301@orkun.us you wrote:
Convenience is irrelevant. This flash is obviously designed with data protection as priority.
Convenience is not irrelevant. The existence of U-Boot itself is just for convenience,
We don't care what the people who designed the flash had in mind. In U-Boot, the design is as follows:
* All flash is writable by default.
* Some parts of the flash may be either implictely or explicitely protected.
* Implicit protection: this covers those areas of the flash that are used to store data that are required for correct operation of U-Boot and the hardware, i. e.
- the U-Boot code and data - environment variables - any FPGA images etc. which are necessary for correct HW operation
* Explicit protection: arbitrary areas which have been protected by the user using the "protect" coommand.
Note:
* "protection" may or may not be implemented using any hardware protection mechanisms which may be available on some chips (and not be available on other types)
* In the current design there is *no* requirement that any explicit protection settings are persistent, i. e. it is perfectly legal (and actually the default, see above) that such settings get lost on reboot, and that the board comes up from reset with unprotected flash
This design shall be implemented by all boards if possible; for features that are shared across several boards like the cfi_flash driver it is mandatory.
Best regards,
Wolfgang Denk