Dear David,
in message 3551A602-F519-11D8-84C7-000393C7979E@student.unsw.edu.au you wrote:
What has the disassembly to do with the values read by the processor? It may be what you _want_ to be read by the CPU, but what do you actually see on your data bus?
The disassembly is derived from the code which was read from the flash. (e.g. Multi-ICE downloads the data from flash, runs it through a disassembler, and displays it as you step through). In order to get the correct disassembly, the correct code has to be in flash.
But again, this is just what the Multi-ICE is telling you. And I bet it accesses the flash memory in a different way than the processor when fetching instructions.
Timing, for example. Also it may use bursts to fetch the data into cache. Depends on your configuration and system setup which you don't bother to share with us.
This is all before the flash timings have been configured, so its using the PXA255's reset values, which are all the slowest as I understand it (and non-burst). I am using two Intel 28F320B3 (Advanced boot block flash memory) chips configured as a single 32-bit wide bank.
Well, attach a logic analyzer and verify which data are actually seen on the bus.
And do you really expect that we check this without any explanation what it wwas derived from, what you changed and why, what your hardware is looking like etc.?
I stopped looking when I saw that your changes violate the Codiing Style requirements as specified in the README.
You're sending 40kB of trash to the list, and expect that we solve a problem for you without being given any relevant data?
Sorry, this is not the way it works.
You've asked for two contradicting qualities -- a small email along with all the possible relevant data. I provided what I thought was the relevant data, and specifically asked if I had got it right (which I guess I didn't).
No. The data you sent was not relevant, and not usable.
If you think that the memset code was critical, you could have simply referred to a known version and provided a diff against the file in the CVS tree. No need to send 500 lines of source when 22 lines of diff will do as well.
Thankyou for your thoughts. I'll try to do it better next time. If you've got any ideas regarding the problem, it would be much appreciated. Is it possible that the PXA could be reading the flash in burst-mode at startup?
See above. Attach a logic analyzer and check what's going on on the bus.
Best regards,
Wolfgang Denk