From: tomasz.figa@gmail.com (Tomasz Figa)
To: linux-arm-kernel@lists.infradead.org
Subject: some question about usermode:kernel mode is not 2:2 or 1:3
Date: Thu, 10 Jan 2013 11:52:22 +0100 [thread overview]
Message-ID: <5478233.oiXe2QDsbJ@flatron> (raw)
In-Reply-To: <CANudz+snNE9shBTosbVK+xV9P0NPNPR3OH3z5ey=+u_FcFTrkQ@mail.gmail.com>
Hi,
On Thursday 10 of January 2013 18:39:25 loody wrote:
> hi all:
> There are some hw limitations on my platform.
> 1. dram size is only 128MB.
> 2. cpu dram physical address range only from 0x0 ~ 0x8000000(128MB)
> that means my PAGE_OFFSET cannot set as 2G or 3G
>
> per above #1 and #2 limitation, I have to change PAGE_OFFSET =
> 0x4000000(64MB) Kernel booting very well.
> but it will fail on running init, the first usermode program.
>
> my question are:
> A. I use codesourcety toolchain, is it possible this failure due to
> toolchain not knowing the size limitation.
> B. if A is correct, should I cross-compile own toolchain to link my own
> kernel?
You seem to confuse physical memory with virtual memory. Here's a nice
article about virtual memory on Linux:
http://linux-mm.org/VirtualMemory
Best regards,
Tomasz Figa
prev parent reply other threads:[~2013-01-10 10:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-10 10:39 some question about usermode:kernel mode is not 2:2 or 1:3 loody
2013-01-10 10:52 ` Tomasz Figa [this message]
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