/* $OpenBSD: armish_start.S,v 1.2 2006/05/29 17:30:26 drahn Exp $ */ /* $NetBSD: iq80321_start.S,v 1.4 2002/10/14 22:32:54 bjh21 Exp $ */ /* * Copyright (c) 2002 Wasabi Systems, Inc. * All rights reserved. * * Written by Jason R. Thorpe for Wasabi Systems, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed for the NetBSD Project by * Wasabi Systems, Inc. * 4. The name of Wasabi Systems, Inc. may not be used to endorse * or promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #include #include .section .start,"ax",%progbits .global _C_LABEL(jornada720_start) _C_LABEL(jornada720_start): #define notsure #ifdef notsure /* Put the processer in SVC mode */ mov r5, sp mrs r4, cpsr_all bic r4, r4, #31 orr r4, r4, #(PSR_SVC32_MODE) msr cpsr_all, r4 mov sp, r5 /* Disable PID virtual address mapping */ mov r4, #0 mcr 15, 0, r4, c13, c0, 0 #endif #undef notsure /* * We will go ahead and disable the MMU here so that we don't * have to worry about flushing caches, etc. * * Note that we may not currently be running VA==PA, which means * we'll need to leap to the next insn after disabing the MMU. */ adr r8, Lunmapped // bic r8, r8, #0xff000000 /* clear upper 8 bits */ // orr r8, r8, #0xc0000000 /* OR in physical base address */ #if 0 mrc p15, 0, r2, c1, c0, 0 bic r2, r2, #CPU_CONTROL_MMU_ENABLE mcr p15, 0, r2, c1, c0, 0 #endif nop nop nop mov pc, r8 /* Heave-ho! */ Lunmapped: /* * We want to construct a memory map that maps us * VA==PA (SDRAM at 0xc0000000) and also double-maps * that space at 0xc0000000 (where the kernel address * space starts). We create these mappings uncached * and unbuffered to be safe. * * We also want to map the various devices we want to * talk to VA==PA during bootstrap. * * We just use section mappings for all of this to make it easy. * * We will put the L1 table to do all this at 0xc0004000. */ adr r0, Lstart mov pc, r0 #if 0 /* * Step 1: Map the entire address space VA==PA. */ adr r0, Ltable ldr r0, [r0] /* r0 = &l1table */ mov r3, #(L1_S_AP(AP_KRW)) orr r3, r3, #(L1_TYPE_S) mov r2, #0x100000 /* advance by 1MB */ mov r1, #0x1000 /* 4096MB */ 1: str r3, [r0], #0x04 add r3, r3, r2 subs r1, r1, #1 bgt 1b /* * Step 2: Map VA 0xc0000000->0xc1ffffff to PA 0xc0000000->0xc1ffffff. */ adr r0, Ltable /* r0 = &l1table */ ldr r0, [r0] mov r3, #(L1_S_AP(AP_KRW)) orr r3, r3, #(L1_TYPE_S) orr r3, r3, #0xc0000000 add r0, r0, #(0xc00 * 4) /* offset to 0xc00xxxxx */ mov r1, #0x20 /* 32MB */ 1: str r3, [r0], #0x04 add r3, r3, r2 subs r1, r1, #1 bgt 1b /* OK! Page table is set up. Give it to the CPU. */ adr r0, Ltable ldr r0, [r0] mcr p15, 0, r0, c2, c0, 0 /* Flush the old TLBs, just in case. */ mcr p15, 0, r0, c8, c7, 0 /* Set the Domain Access register. Very important! */ mov r0, #1 mcr p15, 0, r0, c3, c0, 0 /* Get ready to jump to the "real" kernel entry point... */ ldr r0, Lstart /* OK, let's enable the MMU. */ mrc p15, 0, r2, c1, c0, 0 orr r2, r2, #CPU_CONTROL_MMU_ENABLE mcr p15, 0, r2, c1, c0, 0 nop nop nop /* CPWAIT sequence to make sure the MMU is on... */ mrc p15, 0, r2, c2, c0, 0 /* arbitrary read of CP15 */ mov r2, r2 /* force it to complete */ mov pc, r0 /* leap to kernel entry point! */ Ltable: .word 0xc0004000 #endif /* 0 */ Lstart: .word start