Date: Tue, 17 Mar 2015 10:04:24 -0600 From: Ian Lepore <ian@freebsd.org> To: Stanislav Sedov <stas@freebsd.org> Cc: freebsd-arm@freebsd.org, =?ISO-8859-1?Q?Mat=EDas?= Perret Cantoni <perretcantonim@gmail.com> Subject: Re: hexdumping /dev/mem Message-ID: <1426608264.25614.13.camel@freebsd.org> In-Reply-To: <8033BAE2-9D21-4DB3-AEE9-727B1F3CE9C7@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>
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On Mon, 2015-03-16 at 16:41 -0700, Stanislav Sedov wrote: > > On Mar 16, 2015, at 3:58 PM, Matas Perret Cantoni <perretcantonim@gmail.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’m 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
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