From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Thu, 10 Aug 2000 04:12:14 +0000 Subject: Re: [Linux-ia64] arch/ia64/boot/bootloader.c Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org The code you're quoting is from arch/ia64/boot/bootloader.c, which is used only for the HP simulator. There, we need to emulate PAL/SAL/EFI and the bootloader is taking care of that. It lives in the low address space, so there needs to be a mapping for that code. Kludgy, but it does what we want. --david >>>>> On Thu, 10 Aug 2000 13:12:48 +1000 (EST), Alan Au said: Alan> Can someone please tell me what the first itr mapping (the 1M Alan> page in region 0) is for? Thanks. Alan> /* * Install a translation register that identity maps Alan> the * kernel's 256MB page. */ ia64_clear_ic(flags); Alan> ia64_set_rr( 0, (0x1000 << 8) | (_PAGE_SIZE_1M << 2)); Alan> ia64_set_rr(PAGE_OFFSET, (ia64_rid(0, PAGE_OFFSET) << 8) | Alan> (_PAGE_SIZE_256M << 2)); ia64_srlz_d(); ia64_itr(0x3, 0, Alan> 1024*1024, pte_val(mk_pte_phys(1024*1024, Alan> __pgprot(__DIRTY_BITS|_PAGE_PL_0|_PAGE_AR_RWX))), Alan> _PAGE_SIZE_1M); ia64_itr(0x3, 1, PAGE_OFFSET, Alan> pte_val(mk_pte_phys(0, Alan> __pgprot(__DIRTY_BITS|_PAGE_PL_0|_PAGE_AR_RWX))), Alan> _PAGE_SIZE_256M); Alan> Alan __________ alanau@cse.unsw.edu.au School of Computer Alan> Science and Engineering University of New South Wales Alan> _______________________________________________ Linux-IA64 Alan> mailing list Linux-IA64@linuxia64.org Alan> http://lists.linuxia64.org/lists/listinfo/linux-ia64