In message 45BE7D37.5090601@comcast.net you wrote:
bring it up for completeness. cp.l commands that look like they for sure should generate an alignment exception will not do so if the destination is flash.
Why should they?
Well, my thought on this is that UNIX (and u-boot) also follows the Principle of Least Surprise, namely that like cases tend to work alike. If I type cp.l 0x3 0x10 0x1 on a system that enforces longword (4 byte words) to be aligned, it will throw an exception and not work. I would
Note that it will trap on the unaligned read access at address 0x3.
therefore also expect cp.l 0x3 <some flash address> 0x1 to also throw an exception and not work for the same reason, yet it does not do so. It is
It should trap as well on the unaligned read access at address 0x3 - it should not matter at all what the target address is.
executed as cp.b 0x3 <some flash address> 0x1, which is not what I asked
It's more in the equivalent of "cp.b 3 <flash address> 4"
for. Like I said, this is a nit and probably not important. I expect few people use cp.l to copy into flash anyway. It was just a difference between flash and ram that I noticed.
Indeed, there is a difference.
Best regards,
Wolfgang Denk