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