1 /****************************************************************************
\r
2 * Copyright (c) 2006 by Michael Fischer. All rights reserved.
\r
4 * Redistribution and use in source and binary forms, with or without
\r
5 * modification, are permitted provided that the following conditions
\r
8 * 1. Redistributions of source code must retain the above copyright
\r
9 * notice, this list of conditions and the following disclaimer.
\r
10 * 2. Redistributions in binary form must reproduce the above copyright
\r
11 * notice, this list of conditions and the following disclaimer in the
\r
12 * documentation and/or other materials provided with the distribution.
\r
13 * 3. Neither the name of the author nor the names of its contributors may
\r
14 * be used to endorse or promote products derived from this software
\r
15 * without specific prior written permission.
\r
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
\r
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
\r
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
\r
20 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
\r
21 * THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
\r
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
\r
23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
\r
24 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
\r
25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
\r
26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
\r
27 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
\r
30 ****************************************************************************
\r
34 * 04.03.06 mifi First Version
\r
35 * This version based on an example from Ethernut and
\r
36 * "ARM Cross Development with Eclipse" from James P. Lynch
\r
38 * 26.01.08 mifi Change the code of the init section. Here I have used
\r
39 * some of the source from the Anglia startup.s
\r
40 * Author: Spencer Oliver (www.anglia-designs.com)
\r
41 ****************************************************************************/
\r
44 * Some defines for the program status registers
\r
46 ARM_MODE_USER = 0x10 /* Normal User Mode */
\r
47 ARM_MODE_FIQ = 0x11 /* FIQ Fast Interrupts Mode */
\r
48 ARM_MODE_IRQ = 0x12 /* IRQ Standard Interrupts Mode */
\r
49 ARM_MODE_SVC = 0x13 /* Supervisor Interrupts Mode */
\r
50 ARM_MODE_ABORT = 0x17 /* Abort Processing memory Faults Mode */
\r
51 ARM_MODE_UNDEF = 0x1B /* Undefined Instructions Mode */
\r
52 ARM_MODE_SYS = 0x1F /* System Running in Priviledged Operating Mode */
\r
53 ARM_MODE_MASK = 0x1F
\r
55 I_BIT = 0x80 /* disable IRQ when I bit is set */
\r
56 F_BIT = 0x40 /* disable IRQ when I bit is set */
\r
59 * Register Base Address
\r
61 PRCCU_BASE = 0xA0000000
\r
69 .section .vectors,"ax"
\r
72 /****************************************************************************/
\r
73 /* Vector table and reset entry */
\r
74 /****************************************************************************/
\r
76 ldr pc, ResetAddr /* Reset */
\r
77 ldr pc, UndefAddr /* Undefined instruction */
\r
78 ldr pc, SWIAddr /* Software interrupt */
\r
79 ldr pc, PAbortAddr /* Prefetch abort */
\r
80 ldr pc, DAbortAddr /* Data abort */
\r
81 ldr pc, ReservedAddr /* Reserved */
\r
82 ldr pc, IRQAddr /* IRQ interrupt */
\r
83 ldr pc, FIQAddr /* FIQ interrupt */
\r
86 ResetAddr: .word ResetHandler
\r
87 UndefAddr: .word UndefHandler
\r
88 SWIAddr: .word SWIHandler
\r
89 PAbortAddr: .word PAbortHandler
\r
90 DAbortAddr: .word DAbortHandler
\r
91 ReservedAddr: .word 0
\r
92 IRQAddr: .word IRQHandler
\r
93 FIQAddr: .word FIQHandler
\r
98 .section .init, "ax"
\r
101 .global ResetHandler
\r
102 .global ExitFunction
\r
104 /****************************************************************************/
\r
105 /* Reset handler */
\r
106 /****************************************************************************/
\r
109 * Wait for the oscillator is stable
\r
121 * Setup STR71X, for more information about the register
\r
122 * take a look in the STR71x Microcontroller Reference Manual.
\r
124 * Reference is made to: Rev. 6 March 2005
\r
126 * 1. Map internal RAM to address 0
\r
127 * In this case, we are running always in the RAM
\r
128 * this make no sence. But if we are in flash, we
\r
129 * can copy the interrupt vectors into the ram and
\r
130 * switch to RAM mode.
\r
132 * 2. Setup the PLL, the eval board HITEX STR7 is equipped
\r
133 * with an external 16MHz oscillator. We want:
\r
135 * RCLK: 32MHz = (CLK2 * 16) / 4
\r
143 * 1. Map RAM to the boot memory 0x00000000
\r
145 ldr r0, =PRCCU_BASE
\r
147 str r1, [r0, #PCU_BOOTCR]
\r
151 * 2. Setup PLL start
\r
154 /* Set the prescaling factor for APB and APB1 group */
\r
155 ldr r0, =PRCCU_BASE
\r
156 ldr r1, =0x0000 /* no prescaling PCLKx = RCLK */
\r
157 str r1, [r0, #PCU_PDIVR]
\r
159 /* Set the prescaling factor for the Main System Clock MCLK */
\r
160 ldr r0, =PRCCU_BASE
\r
161 ldr r1, =0x0000 /* no prescaling MCLK = RCLK
\r
162 str r1, [r0, #PCU_MDIVR]
\r
164 /* Configure the PLL1 ( * 16 , / 4 ) */
\r
165 ldr r0, =PRCCU_BASE
\r
167 str r1, [r0, #RCCU_PLL1CR]
\r
169 /* Check if the PLL is locked */
\r
171 ldr r1, [r0, #RCCU_CFR]
\r
175 /* Select PLL1_Output as RCLK clock */
\r
176 ldr r0, =PRCCU_BASE
\r
178 str r1, [r0, #RCCU_CFR]
\r
186 * Setup a stack for each mode
\r
188 msr CPSR_c, #ARM_MODE_UNDEF | I_BIT | F_BIT /* Undefined Instruction Mode */
\r
189 ldr sp, =__stack_und_end__
\r
191 msr CPSR_c, #ARM_MODE_ABORT | I_BIT | F_BIT /* Abort Mode */
\r
192 ldr sp, =__stack_abt_end__
\r
194 msr CPSR_c, #ARM_MODE_FIQ | I_BIT | F_BIT /* FIQ Mode */
\r
195 ldr sp, =__stack_fiq_end__
\r
197 msr CPSR_c, #ARM_MODE_IRQ | I_BIT | F_BIT /* IRQ Mode */
\r
198 ldr sp, =__stack_irq_end__
\r
200 msr CPSR_c, #ARM_MODE_SVC | I_BIT | F_BIT /* Supervisor Mode */
\r
201 ldr sp, =__stack_svc_end__
\r
205 * Now init all the sections
\r
210 * Relocate .data section (Copy from ROM to RAM)
\r
213 ldr r2, =__data_start
\r
223 * Clear .bss section (Zero init)
\r
226 ldr r1, =__bss_start__
\r
227 ldr r2, =__bss_end__
\r
235 * Call C++ constructors
\r
237 ldr r0, =__ctors_start__
\r
238 ldr r1, =__ctors_end__
\r
255 bic r0, r0, #I_BIT | F_BIT /* Enable FIQ and IRQ interrupt */
\r
258 mov r0, #0 /* No arguments */
\r
259 mov r1, #0 /* No arguments */
\r
262 bx r2 /* And jump... */
\r
271 /****************************************************************************/
\r
272 /* Default interrupt handler */
\r
273 /****************************************************************************/
\r
294 .weak UndefHandler, PAbortHandler, DAbortHandler
\r
295 .weak IRQHandler, FIQHandler
\r