From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: fail to disable MMU on ppc 8241 From: Benjamin Herrenschmidt To: llee Cc: linuxppc-dev list In-Reply-To: <40834DC0.2030408@huawei.com> References: <40834DC0.2030408@huawei.com> Content-Type: text/plain Message-Id: <1082352050.1689.9.camel@gaston> Mime-Version: 1.0 Date: Mon, 19 Apr 2004 15:20:51 +1000 Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Mon, 2004-04-19 at 13:55, llee wrote: > Hi, there, > I boot linux (2.6.3) on my ppc 8241 through vxworks bootloader. I'd got > a port (on address 0x70020006) to constrol three LEDs, so I could know > where the kernel going. But after the disable_mmu is called, I lost > control to the LEDs, Any suggestion on this? As I know, vxworks use a > one-to-one mapping MMU setup, I should must constrol the LEDs through > the same address. With mmu off, I suspect the 8241 acts as if the entire address space was cacheable, which is a BAD THING for IOs typically. Ben. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/