[PATCH] ramoops appears geared to not support ARM
Marco Stornelli
marco.stornelli at gmail.com
Sat Oct 29 04:39:47 EDT 2011
(Added linux-arm)
Il 29/10/2011 01:21, Bryan Freed ha scritto:
> I had some difficulty in getting ramoops to work on our ARM systems.
> The driver maps memory with ioremap() which is supposed to map IO memory,
> not physical RAM. This happens to work on x86 and apparently some other
> architectures, but it does not work on ARM.
> Specifically, I see this comment in __arm_ioremap_pfn_caller():
> Don't allow RAM to be mapped - this causes problems with ARMv6+
>
> So here is a patch that hacks around the issue using page_is_ram() to
> differentiate between the two.
>
> Am I missing something here?
> Is ramoops working on any ARM systems yet, and I am just doing something wrong?
>
> My ARM platform reserves a section of RAM for use by ramoops, but it is still
> mapped along with the rest of main memory. This is so /dev/mem can find it
> with xlate_dev_mem_ptr().
> On x86, I see our BIOS reserves the memory so that it is not counted as main
> memory, and it is not mapped until ramoops ioremaps it.
>
> Bryan Freed (1):
> ramoops: Add support for ARM systems.
>
> drivers/char/ramoops.c | 67 +++++++++++++++++++++++++++++++++++++----------
> 1 files changed, 52 insertions(+), 15 deletions(-)
>
Can some ARM guys give an opinion about that?
Thanks.
Marco
More information about the linux-arm-kernel
mailing list