On Wed, Jun 06, 2007 at 11:16:03PM +0700, Darmawan Salihun wrote:
- Kernel driver allowing unrestricted reads and writes to top 16MB.
The current version of the driver code is capable of mapping *anywhere* within the 4GB physical address space. It shouldn't be a problem to restrict it to the top 16MB.
We should make that 2MB until we actually support larger flash parts btw.
The logic of the mapping process is as follows: a. The physical memory address range is mapped into the kernel's virtual memory address range b. The kernel's virtual memory address range is then mapped to the "requesting" user mode virtual memory address range.
Sounds good.
- Kernel driver implementing the lowest level flash chip API.
Possibly using some macro language so that reboot isn't neccessary to upgrade flash support.
Can you please elaborate more on this idea?
Still a hard limit of 2MB space in the kernel driver.
The application would "upload" a protocol description to the kernel driver so that the kernel driver does not have to change just because timing parameters or special byte values used in programming sequences change for a newly added flash chips. In practise this idea may turn out to allow just as much damage as (1) and in that case we should just stick with (1).
//Peter