Gary Thomas wrote:
Jim Seymour wrote:
I'm curious, though. The Toshiba drivers seem to assume the flash is in code space - although NAND flash (as I understand it) cannot be used to directly execute code. Is this a legacy from the NOR flash driver it was based on? Or is there some eCos weirdness that I need to be aware of?

NAND FLASH is treated differently - it cannot be accessed
directly and the 'flash_read_buf()' function is used to stage
a portion of the FLASH into RAM.  [...]

What prompted my question is the function "flash_code_overlaps" in
.../devs/flash/toshiba/tc58xxx/current/include/flash_tc58xxx.inl

It compares the flash address with "stext" and "etext" to determine whether it "overlaps currently running code".

However, since we cannot execute out of NAND flash (and, in fact, do not map the NAND flash into the normal memory address space), it seems that this function should always return false.

Am I misunderstanding this?  Or is it a (minor) bug?

--
Jim Seymour, Cipher Systems, Inc., 503-617-7447, http://www.cipher.com


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