* Problem on JTAG debug for ARM920T when mmu/cache is turned on
@ 2005-10-07 5:26 #HE XUZHOU#
2005-10-07 12:56 ` Daniel Jacobowitz
0 siblings, 1 reply; 2+ messages in thread
From: #HE XUZHOU# @ 2005-10-07 5:26 UTC (permalink / raw)
To: gdb
I am writing a program for JTAG debug. My target board is ARM920T. I found a single stepping problem when the MMU/CACHE is turn on. If the cache is turn on, single stepping doesn't work. If the cache is turn off, single stepping then works well.I guess this is casued by data/instruction cache. So, I am wandering what I should handle the MMU/CACHE when ARM920T enters debug state with mmu/cache is turned on? I have TWO questions and hope I can get some suggestions here. Thank you!
1. Should I turn off the MMU after ARM920T enter debug state and turn it on before ARM920T is restarted?
2. Should I turn off the cache after ARM920T enter debug state and turn it on before ARM920T is restarted? Or just flush the cahce?
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Problem on JTAG debug for ARM920T when mmu/cache is turned on
2005-10-07 5:26 Problem on JTAG debug for ARM920T when mmu/cache is turned on #HE XUZHOU#
@ 2005-10-07 12:56 ` Daniel Jacobowitz
0 siblings, 0 replies; 2+ messages in thread
From: Daniel Jacobowitz @ 2005-10-07 12:56 UTC (permalink / raw)
To: #HE XUZHOU#; +Cc: gdb
On Fri, Oct 07, 2005 at 01:26:02PM +0800, #HE XUZHOU# wrote:
> I am writing a program for JTAG debug. My target board is ARM920T. I found a single stepping problem when the MMU/CACHE is turn on. If the cache is turn on, single stepping doesn't work. If the cache is turn off, single stepping then works well.I guess this is casued by data/instruction cache. So, I am wandering what I should handle the MMU/CACHE when ARM920T enters debug state with mmu/cache is turned on? I have TWO questions and hope I can get some suggestions here. Thank you!
>
> 1. Should I turn off the MMU after ARM920T enter debug state and turn
> it on before ARM920T is restarted? 2. Should I turn off the cache
> after ARM920T enter debug state and turn it on before ARM920T is
> restarted? Or just flush the cahce?
This depends on your target and debug stub; it is a problem with your
stub. You probably want to flush the cache when writing to memory,
which includes for single step breakpoints.
--
Daniel Jacobowitz
CodeSourcery, LLC
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2005-10-07 12:56 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2005-10-07 5:26 Problem on JTAG debug for ARM920T when mmu/cache is turned on #HE XUZHOU#
2005-10-07 12:56 ` Daniel Jacobowitz
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).