/* * Memory Setup stuff - taken from blob memsetup.S * * Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl) and * Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl) * 2003-2004 (c) MontaVista Software, Inc. * * See file CREDITS for list of people who contributed to this * project. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, * MA 02111-1307 USA */ #include "config.h" #include "version.h" .globl lowlevel_init lowlevel_init: /* The ADS GC+ for Linux Boot Rom Ver. 1.73 does memory init for us. * However the darn thing leaves the MMU enabled before handing control * over to us. So we need to disable the MMU and we use lowlevel_init * to do it. */ @ The following code segment was borrowed with gratitude from: @ linux-2.4.19-rmk7/arch/arm/boot/compressed/head-sa1100.S @ Data cache might be active. @ Be sure to flush kernel binary out of the cache, @ whatever state it is, before it is turned off. @ This is done by fetching through currently executed @ memory to be sure we hit the same cache. bic r2, pc, #0x1f add r3, r2, #0x4000 @ 16 kb is quite enough... 1: ldr r0, [r2], #32 teq r2, r3 bne 1b mcr p15, 0, r0, c7, c10, 4 @ drain WB mcr p15, 0, r0, c7, c7, 0 @ flush I & D caches @ disabling MMU and caches mrc p15, 0, r0, c1, c0, 0 @ read control reg bic r0, r0, #0x0d @ clear WB, DC, MMU bic r0, r0, #0x1000 @ clear Icache mcr p15, 0, r0, c1, c0, 0 nop nop nop nop nop b 2f 2: nop nop nop nop nop mov pc, lr