Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> writes:
> I remember Marc had some trouble with the mmu/cache implementation on
> PXA. I don't know the details though. Maybe you have to dig through
> the manuals/kernel code to find out the differences between the normal
> arm v5 and pxa.
Ah, I know what happens now, and it's tricky.
First of all, you're right, there's a flat uncached mapping, I was misled by
the function name "create_section", without looking closely at it. I thought
it created the first section, not all the 4096 1MBytes section of a 4GB
address space.
It would deserve a "create_sections" name, in plural form.
Now, for the serial UDC not working, there comes the fun.
What's happening is that I'm using a default environment, with the init
script in [1]. This script has an error somewhere.
In barebox_startup(), we have :
if (!stat("/env/bin/init", &s)) {
run_command("source /env/bin/init", 0);
And here is the trickery:
- in the NOMMU case, the run_command() returns, and the code continues to the
eternal loop of run_shell(), which calls console.getc(), which calls
poller(), which call the UDC poll method
=> the gadget does work
=> I have a console, hurray !
- in the MMU case, the run_command() never returns, and the poller method is
never called. I traced that with my leds.
=> the gadget does *not* work
So the problem was not the IO mapping, but a difference in run_command() between
MMU and non-MMU config. Moreover, in non-MMU case, once my console is connected,
I see a message :
> running /env/bin/init...
> syntax error
I the MMU case, as the gadget doesn't work, I'm blind, so I can't really tell
what is happening and which is the impact of MMU over run_command()...
Cheers.
--
Robert
[1] Script:
#!/bin/sh
#led orange 1
PATH=/env/bin
export PATH
. /env/config
while [ -z $toto ]; do
led orange 1
readline "Give me a word" word
echo "I've got your $word"
done
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