From: sk.syed2@gmail.com (sk.syed2)
To: kernelnewbies@lists.kernelnewbies.org
Subject: ARM : Kernel : Setting up of MMU in head.S
Date: Wed, 30 Mar 2011 14:25:28 -0500 [thread overview]
Message-ID: <AANLkTimCGdjMPpB7qHg_HBvNAmh79HhvNZSr0spJa+uh@mail.gmail.com> (raw)
In-Reply-To: <AANLkTikbzjKepm7+ZhmA-3Vq33vADPaXrVdJGRc284OS@mail.gmail.com>
> The 2 lines above
> 1:? orr??? r3, r7, r5, lsl #20??? ??? @ flags + kernel base ==> Correct
> ??? str??? r3, [r4, r5, lsl #2]??? ??? @ identity mapping? ==> ??
>
> create a section entry using index based on physical address.
Lets say before mmu is turned on PC is at physical address XXX, also
say at XXX there is going to be mmu on instruction. The next
instruction fetch would be from XXX + 4 which would now be VIRTUAL
address(as mmu is turned on), which should still get converted to (via
page tables set up as above) to XXX + 4 (in physical). This is called
identity mapping as specified in the comments. Hope this helps.
-syed
next prev parent reply other threads:[~2011-03-30 19:25 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-30 15:19 ARM : Kernel : Setting up of MMU in head.S Prakash K.B.
2011-03-30 19:25 ` sk.syed2 [this message]
2011-03-31 6:31 ` Prakash K.B.
2011-03-30 21:35 ` Dave Hylands
2011-03-30 22:29 ` Dave Hylands
2011-03-31 6:01 ` Prakash K.B.
2011-03-31 13:59 ` Dave Hylands
2011-04-03 8:01 ` Prakash K.B.
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