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gumstix_start.S revision 1.13
      1 /*	$NetBSD: gumstix_start.S,v 1.13 2014/05/23 13:56:18 kiyohara 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 "opt_cputypes.h"
     63 #include "opt_gumstix.h"
     64 
     65 #include <machine/asm.h>
     66 #include <arm/armreg.h>
     67 #include "assym.h"
     68 
     69 RCSID("$NetBSD: gumstix_start.S,v 1.13 2014/05/23 13:56:18 kiyohara Exp $")
     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 #if defined(CPU_XSCALE_PXA250) || defined(CPU_XSCALE_PXA270)
     78 #define	CPWAIT_BRANCH							  \
     79 	sub	pc, pc, #4
     80 #else
     81 #define	CPWAIT_BRANCH
     82 #endif
     83 
     84 #define	CPWAIT(tmp)							  \
     85 	mrc	p15, 0, tmp, c2, c0, 0	/* arbitrary read of CP15 */	; \
     86 	mov	tmp, tmp		/* wait for it to complete */	; \
     87 	CPWAIT_BRANCH			/* branch to next insn */
     88 
     89 /*
     90  * Kernel start routine for GUMSTIX
     91  * this code is excuted at the very first after the kernel is loaded
     92  * by U-Boot.
     93  */
     94 	.text
     95 
     96 	.global	_C_LABEL(gumstix_start)
     97 _C_LABEL(gumstix_start):
     98 	/*
     99 	 * gumstix's loader is U-boot.  it's running on RAM
    100 	 */
    101 
    102 	/* Our page table might be cached.  Disable D-cache beforehand. */
    103 	mrc	p15, 0, r4, c1, c0, 0
    104 	bic	r4, r4, #CPU_CONTROL_DC_ENABLE
    105 	mcr	p15, 0, r4, c1, c0, 0
    106 
    107 	/*
    108 	 *  Kernel is loaded in SDRAM (0xa0200000..), and is expected to run
    109 	 *  in VA 0xc0200000.. (GUMSTIX)
    110 	 *  VA == PA if OVERO.
    111 	 */
    112 
    113 	/* save u-boot's args */
    114 	adr	r4, u_boot_args
    115 	nop
    116 	nop
    117 	nop
    118 	stmia	r4!, {r0, r1, r2, r3}
    119 	nop
    120 	nop
    121 	nop
    122 
    123 	/* Calculate RAM size */
    124 	adr	r4, ram_size
    125 #if defined(GUMSTIX)
    126 	ldr	r0, [r4]
    127 
    128 	mrc	p15, 0, r1, c0, c0, 0
    129 	and	r1, r1, #CPU_ID_XSCALE_COREGEN_MASK
    130 	cmp	r1, #0x4000
    131 	bne	3f			/* goto 3f, if basix or connex */
    132 0:
    133 	/* check memory size, if verdex or verdex-pro */
    134 	add	r3, r4, r0
    135 	ldr	r1, [r3]
    136 	cmp	r0, r1
    137 	beq	2f
    138 1:
    139 	add	r0, r0, r0		/* r0 <<= 1 */
    140 	str	r0, [r4]
    141 	b	0b
    142 2:
    143 	mvn	r1, r1			/* r1 ^= 0xffffffff */
    144 	str	r1, [r3]
    145 	ldr	r2, [r4]
    146 	cmp	r1, r2
    147 	beq	3f
    148 	str	r0, [r3]		/* restore */
    149 	b	1b
    150 3:
    151 #elif defined(OVERO)
    152 	mov	r1, #0x7f000000		/* mask */
    153 	orr	r1, r1, #0x00e00000	/* mask */
    154 	mov	r3, #0x6d000000		/* OMAP34xx SDRC */
    155 	add	r3, r3, #0x0080		/* CS0 MCFG */
    156 	ldr	r2, [r3]
    157 	and	r0, r1, r2, lsl #13
    158 	add	r3, r3, #0x0030		/* CS1 MCFG */
    159 	ldr	r2, [r3]
    160 	and	r2, r1, r2, lsl #13
    161 	add	r0, r0, r2
    162 #endif
    163 	str	r0, [r4]
    164 
    165 	/* Build page table from scratch */
    166 	ldr	r0, Lstartup_pagetable	/* pagetable */
    167 	adr	r4, mmu_init_table
    168 	b	5f
    169 
    170 4:
    171 	str	r3, [r0, r2, lsl #2]
    172 	add	r2, r2, #1
    173 	add	r3, r3, #(L1_S_SIZE)
    174 	adds	r1, r1, #-1
    175 	bhi	4b
    176 5:
    177 	ldmia	r4!, {r1, r2, r3}	/* # of sections, PA|attr, VA */
    178 	lsr	r2, r2, #L1_S_SHIFT
    179 	cmp	r1, #0
    180 	bne	4b
    181 
    182 	mcr	p15, 0, r0, c2, c0, 0	/* Set TTB */
    183 	mcr	p15, 0, r0, c8, c7, 0	/* Flush TLB */
    184 
    185 #if defined(CPU_CORTEXA8)
    186 	mcr	p15, 0, r0, c2, c0, 1	/* Set TTB1 */
    187 	mov	r0, #TTBCR_S_N_1
    188 	mcr	p15, 0, r0, c2, c0, 2	/* Set TTBCR */
    189 	mov	r0, #0
    190 	mcr	p15, 0, r0, c8, c7, 0	/* Flush TLB */
    191 #endif
    192 
    193 	/*
    194 	 * Set the Domain Access register.  Very important!
    195 	 * startup_pagetable puts to domain 0 now.
    196 	 */
    197 #define KERNEL_DOMAIN(x)	((x) << (PMAP_DOMAIN_KERNEL << 1))
    198 	mov	r0, #(KERNEL_DOMAIN(DOMAIN_CLIENT) | DOMAIN_CLIENT)
    199 	mcr	p15, 0, r0, c3, c0, 0
    200 
    201 	/* Enable MMU and etc. */
    202 	mrc	p15, 0, r0, c1, c0, 0
    203 #if defined(CPU_XSCALE_PXA250) || defined(CPU_XSCALE_PXA270)
    204 	orr	r0, r0, #CPU_CONTROL_SYST_ENABLE
    205 #endif
    206 #if defined(CPU_CORTEXA8)
    207 	/* Disable L2 cache beforehand. */
    208 	mrc	p15, 0, r1, c1, c0, 1
    209 	bic	r1, r1, #0x2		/* clear L2EN */
    210 	mcr	p15, 0, r1, c1, c0, 1
    211 
    212 	orr	r0, r0, #CPU_CONTROL_AFLT_ENABLE | CPU_CONTROL_DC_ENABLE
    213 	orr	r0, r0, #CPU_CONTROL_BPRD_ENABLE | CPU_CONTROL_IC_ENABLE
    214 #endif
    215 	orr	r0, r0, #CPU_CONTROL_MMU_ENABLE
    216 	mcr	p15, 0, r0, c1, c0, 0
    217 	/*
    218 	 * Ensure that the coprocessor has finished turning on the MMU.
    219 	 */
    220 	CPWAIT(r0)
    221 
    222 	/* Jump to kernel code in TRUE VA */
    223 	ldr	r0, Lstart
    224 	bx	r0
    225 
    226 Lstart:
    227 	.word	start
    228 
    229 #ifndef STARTUP_PAGETABLE_ADDR
    230 #if defined(GUMSTIX)
    231 #define STARTUP_PAGETABLE_ADDR 0xa0000000	/* aligned 16kByte */
    232 #elif defined(OVERO)
    233 #define STARTUP_PAGETABLE_ADDR 0x80000000	/* aligned 16kByte */
    234 #endif
    235 #endif
    236 Lstartup_pagetable:
    237 	.word	STARTUP_PAGETABLE_ADDR
    238 
    239 	.globl	_C_LABEL(u_boot_args)
    240 u_boot_args:
    241 	.space	16			/* r0, r1, r2, r3 */
    242 
    243 	.globl	_C_LABEL(ram_size)
    244 ram_size:
    245 	.word	0x04000000		/* 64Mbyte */
    246 
    247 
    248 #define MMU_INIT(va, pa, n_sec, attr)	  \
    249 	.word	n_sec			; \
    250 	.word	(va)			; \
    251 	.word	(pa) | (attr)		;
    252 
    253 mmu_init_table:
    254 #if defined(GUMSTIX)
    255 	/* fill all table VA==PA */
    256 	MMU_INIT(0x00000000, 0x00000000,
    257 	    1 << (32 - L1_S_SHIFT), L1_S_PROTO | L1_S_AP_KRW)
    258 
    259 #define SDRAM_START	0xa0000000
    260 
    261 	/* map SDRAM VA==PA, write-back cacheable (first 64M only)*/
    262 	MMU_INIT(SDRAM_START, SDRAM_START,
    263 	    64, L1_S_PROTO | L1_S_C | L1_S_AP_KRW)
    264 
    265 	/* map VA 0xc0000000..0xc3ffffff to PA 0xa0000000..0xa3ffffff */
    266 	MMU_INIT(0xc0000000, SDRAM_START,
    267 	    64, L1_S_PROTO | L1_S_C | L1_S_AP_KRW)
    268 
    269 #elif defined(OVERO)
    270 	/* fill all table VA==PA */
    271 	MMU_INIT(0x00000000, 0x00000000,
    272 	    1 << (32 - L1_S_SHIFT), L1_S_PROTO | L1_S_APv7_KRW)
    273 
    274 #define SDRAM_START	0x80000000
    275 
    276 	/* Map VA to PA, write-back cacheable (first 64M only) */
    277 	MMU_INIT(KERNEL_BASE & 0xffffffff, SDRAM_START,
    278 	    64, L1_S_PROTO | L1_S_B | L1_S_C | L1_S_APv7_KRW)
    279 #endif
    280 
    281 	MMU_INIT(0, 0, 0, 0)		/* end of table */
    282