On Wed, Jun 06, 2007 at 11:16:03PM +0700, Darmawan Salihun wrote: > > 1. 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. > > 2. 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 -- linuxbios mailing list linuxbios@linuxbios.org http://www.linuxbios.org/mailman/listinfo/linuxbios