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      1 /*	$NetBSD: mmnet_start.S,v 1.1 2011/11/04 17:40:48 aymeric Exp $ */
      2 /*
      3  * Copyright (C) 2005, 2006 WIDE Project and SOUM Corporation.
      4  * All rights reserved.
      5  *
      6  * Written by Takashi Kiyohara and Susumu Miki for WIDE Project and SOUM
      7  * Corporation.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. Neither the name of the project nor the name of SOUM Corporation
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT and SOUM CORPORATION ``AS IS''
     22  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT AND SOUM CORPORATION
     25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     31  * POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 /*
     34  * Copyright (c) 2002, 2003  Genetec Corporation.  All rights reserved.
     35  * Written by Hiroyuki Bessho for Genetec Corporation.
     36  *
     37  * Redistribution and use in source and binary forms, with or without
     38  * modification, are permitted provided that the following conditions
     39  * are met:
     40  * 1. Redistributions of source code must retain the above copyright
     41  *    notice, this list of conditions and the following disclaimer.
     42  * 2. Redistributions in binary form must reproduce the above copyright
     43  *    notice, this list of conditions and the following disclaimer in the
     44  *    documentation and/or other materials provided with the distribution.
     45  * 3. The name of Genetec Corporation may not be used to endorse or
     46  *    promote products derived from this software without specific prior
     47  *    written permission.
     48  *
     49  * THIS SOFTWARE IS PROVIDED BY GENETEC CORPORATION ``AS IS'' AND
     50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     51  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     52  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL GENETEC CORPORATION
     53  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     54  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     55  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     56  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     57  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     58  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     59  * POSSIBILITY OF SUCH DAMAGE.
     60  */
     61 
     62 #include <machine/asm.h>
     63 #include <arm/armreg.h>
     64 #include <arm/arm32/pte.h>
     65 #include <arm/arm32/pmap.h>		/* for PMAP_DOMAIN_KERNEL */
     66 
     67 #ifndef SDRAM_START
     68 #define SDRAM_START	0x20000000
     69 #endif
     70 
     71 /*
     72  * CPWAIT -- Canonical method to wait for CP15 update.
     73  * NOTE: Clobbers the specified temp reg.
     74  * copied from arm/arm/cpufunc_asm_xscale.S
     75  * XXX: better be in a common header file.
     76  */
     77 #define	CPWAIT_BRANCH							 \
     78 	sub	pc, pc, #4
     79 
     80 #define	CPWAIT(tmp)							 \
     81 	mrc	p15, 0, tmp, c2, c0, 0	/* arbitrary read of CP15 */	;\
     82 	mov	tmp, tmp		/* wait for it to complete */	;\
     83 	CPWAIT_BRANCH			/* branch to next insn */
     84 
     85 /*
     86  * Kernel start routine for the Propox MMnet 1002
     87  * this code is executed at the very beginning after the kernel is loaded
     88  * by U-Boot.
     89  */
     90 	.text
     91 
     92 	.global	_C_LABEL(mmnet_start)
     93 _C_LABEL(mmnet_start):
     94 	/*
     95 	 *  Kernel is loaded in SDRAM (0x20200000), and is expected to run
     96 	 *  in VA 0xc0200000..
     97 	 */
     98 	/* save u-boot's args */
     99 	adr	r4, u_boot_args
    100 	nop
    101 	nop
    102 	nop
    103 	stmia	r4!, {r0, r1, r2, r3}
    104 	nop
    105 	nop
    106 	nop
    107 
    108 	/* Calculate RAM size */
    109 	adr	r4, ram_size
    110 	ldr	r0, [r4]
    111 0:
    112 	add	r3, r4, r0
    113 	ldr	r1, [r3]
    114 	cmp	r0, r1
    115 	beq	2f
    116 1:
    117 	add	r0, r0, r0	/* r0 <<= 1 */
    118 	str	r0, [r4]
    119 	b	0b
    120 2:
    121 	mvn	r1, r1		/* r1 ^= 0xffffffff */
    122 	str	r1, [r3]
    123 	ldr	r2, [r4]
    124 	cmp	r1, r2
    125 	beq	3f
    126 	str	r0, [r3]	/* restore */
    127 	b	1b
    128 3:
    129 	str	r0, [r4]
    130 
    131 	/* build page table from scratch */
    132 	ldr	r0, Lstartup_pagetable		/* pagetable */
    133 	adr	r4, mmu_init_table
    134 	b	5f
    135 
    136 4:
    137 	str	r3, [r0, r2]
    138 	add	r2, r2, #4
    139 	add	r3, r3, #(L1_S_SIZE)
    140 	adds	r1, r1, #-1
    141 	bhi	4b
    142 5:
    143 	ldmia	r4!, {r1, r2, r3}	/* # of sections, PA|attr, VA */
    144 	cmp	r1, #0
    145 	bne	4b
    146 
    147 	mcr	p15, 0, r0, c2, c0, 0	/* Set TTB */
    148 	mcr	p15, 0, r0, c8, c7, 0	/* Flush TLB */
    149 
    150 	/* Set the Domain Access register.  Very important! */
    151         mov     r0, #((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT)
    152 	mcr	p15, 0, r0, c3, c0, 0
    153 
    154 	/* Enable MMU */
    155 	mrc	p15, 0, r0, c1, c0, 0
    156 	orr	r0, r0, #CPU_CONTROL_SYST_ENABLE
    157 	orr	r0, r0, #CPU_CONTROL_MMU_ENABLE
    158 	mcr	p15, 0, r0, c1, c0, 0
    159 	CPWAIT(r0)
    160 
    161 	/* Jump to kernel code in TRUE VA */
    162 	adr	r0, Lstart
    163 	ldr	pc, [r0]
    164 
    165 Lstart:
    166 	.word	start
    167 
    168 #ifndef STARTUP_PAGETABLE_ADDR
    169 #define STARTUP_PAGETABLE_ADDR 0x20000000	/* aligned 16kByte */
    170 #endif
    171 Lstartup_pagetable:
    172 	.word	STARTUP_PAGETABLE_ADDR
    173 
    174 	.globl	_C_LABEL(u_boot_args)
    175 u_boot_args:
    176 	.space	16			/* r0, r1, r2, r3 */
    177 
    178 	.globl	_C_LABEL(ram_size)
    179 ram_size:
    180 	.word	0x04000000		/* 64Mbyte */
    181 
    182 
    183 #define MMU_INIT(va,pa,n_sec,attr) \
    184 	.word	n_sec					    ; \
    185 	.word	4 * ((va) >> L1_S_SHIFT)		    ; \
    186 	.word	(pa) | (attr)				    ;
    187 
    188 mmu_init_table:
    189 	/* fill all table VA==PA */
    190 	MMU_INIT(0x00000000, 0x00000000,
    191 	    1 << (32 - L1_S_SHIFT), L1_TYPE_S | L1_S_AP(AP_KRW))
    192 
    193 	/* map SDRAM VA==PA, WT cacheable */
    194 	MMU_INIT(SDRAM_START, SDRAM_START,
    195 	    64, L1_TYPE_S | L1_S_C | L1_S_AP(AP_KRW))
    196 
    197 	/* map VA 0xc0000000..0xc3ffffff to PA 0x20000000..0x23ffffff */
    198 	MMU_INIT(0xc0000000, SDRAM_START,
    199 	    64, L1_TYPE_S | L1_S_C | L1_S_AP(AP_KRW))
    200 
    201 	.word	0			/* end of table */
    202