Date: Tue, 17 Mar 2015 14:37:07 -0300 From: =?UTF-8?Q?Mat=C3=ADas_Perret_Cantoni?= <perretcantonim@gmail.com> To: Ian Lepore <ian@freebsd.org> Cc: freebsd-arm@freebsd.org Subject: Re: hexdumping /dev/mem Message-ID: <CADLKG035a5eXWBh_rXwNKbNcZMj9QVwqYOsi2yqgijeEZ1PNCA@mail.gmail.com> In-Reply-To: <1426608264.25614.13.camel@freebsd.org> References: <CADLKG01HXRf9FE0JZ3hDdr6Ap-AbLM0r3TmhfLNOfwAUUqmbdA@mail.gmail.com> <29227F8C-4A83-4C95-9CD2-BA14E797A882@sbcglobal.net> <CADLKG02ugra2ToUH4t_oy3BLQU36dqdY761wtx3YqVSgG3vp8A@mail.gmail.com> <8033BAE2-9D21-4DB3-AEE9-727B1F3CE9C7@freebsd.org> <1426608264.25614.13.camel@freebsd.org>
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2015-03-17 13:04 GMT-03:00 Ian Lepore <ian@freebsd.org>: > On Mon, 2015-03-16 at 16:41 -0700, Stanislav Sedov wrote: >> > On Mar 16, 2015, at 3:58 PM, Matas Perret Cantoni <perretcantonim@gmai= l.com> wrote: >> > >> > I couldn't find any man page for "kdb" or "db", and the help command >> > of db didn't help much. >> >> The only relevant manual pages are ddb(4) and ddb(8), I=E2=80=99m afraid= . >> But they have plenty of information. Nothing on devmap though. >> > > show devmap and show physmem are arm-specific commands I added a while > back, but didn't document anywhere except in the builtin help display. > > Accessing device registers from ddb is possible because the access is > all within the kernel (unlike with /dev/[k]mem where the pages have to > be mapped into user space, which can't be done safely on arm). But you > still have to be careful about what other device drivers might be doing > with the same registers (if there are drivers attached for that > hardware). > > -- Ian > > Thank you everyone. All this is very helpful. Matias.-
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