From: sophian.yoma@gmail.com (yoma sophian)
To: linux-arm-kernel@lists.infradead.org
Subject: how to mapping device memory in head.S
Date: Sun, 12 Apr 2015 20:23:59 +0800 [thread overview]
Message-ID: <CADUS3onGVjDd3Mquda2bgeLFvmxZUUYdiwzJ4nd7XjhyyudiDw@mail.gmail.com> (raw)
hi all:
I need to map peripheral address in head.S for early usage.
And I found in arm/kernel/head.S, there is CONFIG_DEBUG_LL for
mapping low level uart.
My questions are:
1. CONFIG_DEBUG_LL is using short-descriptor 1st-level section
descriptor formats. Is it possible to use short-descriptor 2nd-level
small page descriptor in head.S?
2. The peripheral mapping virtual address created in head.S is need to
access even after paging_init. Is it possible to put the mapping in
the persistent mapping in head.S?
appreciate your kind help in advance,
next reply other threads:[~2015-04-12 12:23 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-12 12:23 yoma sophian [this message]
2015-04-12 19:14 ` how to mapping device memory in head.S Russell King - ARM Linux
2015-04-13 1:30 ` yoma sophian
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