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[/] [openrisc/] [trunk/] [rtos/] [ecos-3.0/] [packages/] [hal/] [arm/] [gps4020/] [current/] [support/] [download/] [gps4020_start.S] - Blame information for rev 786

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//-------------------------------------------------------------------
//
// gp4020_start.S
//
//-------------------------------------------------------------------
//
// Copyright (C) 2003, MLB Associates.
//
// This file contains basic startup code for the GPS4020 platform.
// After initialization, it will call a single "C" function 'main()'
//
// Note: this program assumes that it has been downloaded into the
// on-chip SRAM via the BOOTSTRAP mechanism, so on-chip SRAM is
// located at address 0x00000000 and external ROM/FLASH is at
// address 0x60000000
//
 
        .macro  lab,lbl
.\lbl:  .long   \lbl
        .endm
 
        .macro  blr
        mov     pc,lr
        .endm
 
        .equ    MPC_BASE_ADDRESS,         0xE0008000
        .equ    MPC_AREA1_CONFIG,         0x00000000
        .equ    MPC_AREA2_CONFIG,         0x00000004
        .equ    MPC_AREA3_CONFIG,         0x00000008
        .equ    MPC_AREA4_CONFIG,         0x0000000C
        .equ    GPIO_BASE_ADDRESS,        0xE0005000
        .equ    GPIO_DIRECTION_REG_OFFSET,0x00000000
        .equ    GPIO_READ_REG_OFFSET,     0x00000004
        .equ    GPIO_WRITE_REG_OFFSET,    0x00000008
        .equ    UART1_BASE_ADDRESS,       0xE0018000
        .equ    UART_TXBUF,               0x00000010
        .equ    UART_STATUS,              0x0000000C
        .equ    UART_STATUS_TXEMPTY,      0x00000002
 
        .text
        .global __exception_handlers
__exception_handlers:
         b       reset                           // 0x00
         ldr     pc,.undefined_instruction       // 0x04
         ldr     pc,.software_interrupt          // 0x08 start && software int
         ldr     pc,.abort_prefetch              // 0x0C
         ldr     pc,.abort_data                  // 0x10
         .word   0                               // unused
         ldr     pc,.IRQ                         // 0x18
         ldr     pc,.FIQ                         // 0x1C
 
         .global vectors
vectors:
         .long   reset                           // 0x20
         lab     undefined_instruction           // 0x24
         lab     software_interrupt              // 0x28
         lab     abort_prefetch                  // 0x2C
         lab     abort_data                      // 0x30
         .word   0                               // 0x34
         lab     IRQ                             // 0x38
         lab     FIQ                             // 0x3C
 
        .arm        @ AKA ".code32"
        .align 2     @ Align code on 2^2 = 4 byte intervals
 
        .global start
start:
reset:
 
/*--------------------------------------------------------------------------*/
// Setup the GPIO and the ARM registers
 
// make GPIO[0..7] outputs - note: GPIO4 is used for Rx on UART1!
 
        ldr     r1,=GPIO_BASE_ADDRESS
        ldr    r0, [r1,#GPIO_DIRECTION_REG_OFFSET]
        and    r0, r0, #0b00010000    @ 0 = output, 1 = input
        str    r0, [r1,#GPIO_DIRECTION_REG_OFFSET]        @ Store value (DON'T use strb)
 
        ldr     r1,=MPC_BASE_ADDRESS
        ldr     r2,=0xFF00002D                  // 0x6xxxxxxx, 16bit R/W RAM
        str     r2,[r1,#MPC_AREA1_CONFIG]
 
        ldr     r1,=MPC_BASE_ADDRESS
        ldr     r2,=0x00000069                  // 0x2xxxxxxx, 16bit R/W RAM
        str     r2,[r1,#MPC_AREA2_CONFIG]
 
        ldr     r2,[r1,#MPC_AREA3_CONFIG]
        ldr     r2,=0x00000021                  // 0x4xxxxxxx, 16bit peripheral
        str     r2,[r1,#MPC_AREA3_CONFIG]
 
        ldr     r2,[r1,#MPC_AREA4_CONFIG]
        ldr     r2,=0x0000006E                  // 0x0xxxxxxx, 32bit memory
        str     r2,[r1,#MPC_AREA4_CONFIG]
 
        ldr     sp,=_stack
        bl      main
 
10:     ldr     r1,=GPIO_BASE_ADDRESS
        mov     r0,#0
        str    r0, [r1,#GPIO_WRITE_REG_OFFSET]
        b       10b
 
//
// Exception handlers
//
undefined_instruction:      // 0x24
        mov     r0,#0x24
        b       exception
software_interrupt:         // 0x28
        mov     r0,#0x28
        b       exception
abort_prefetch:             // 0x2C
        mov     r0,#0x2C
        b       exception
abort_data:                 // 0x30
        mov     r0,#0x30
        b       exception
IRQ:                        // 0x38
        mov     r0,#0x38
        b       exception
FIQ:                        // 0x3C
        mov     r0,#0x3C
        b       exception
 
exception:
        mov     r8,lr       // Location of failure
        mov     r9,r0
00:
        ldr     r1,=GPIO_BASE_ADDRESS
        str    r9, [r1,#GPIO_WRITE_REG_OFFSET]
        ldr     r3,=0x100000
10:     nop
        sub     r3,r3,#1
        cmp     r3,#0
        bne     10b
        str     r3,[r1,#GPIO_WRITE_REG_OFFSET]
        ldr     r3,=0x80000
20:     nop
        sub     r3,r3,#1
        cmp     r3,#0
        bne     20b
 
        ldr     r1,=msg
        bl      _puts
        mov     r1,r8,lsr #24
        bl      _puthex
        mov     r1,r8,lsr #16
        bl      _puthex
        mov     r1,r8,lsr #8
        bl      _puthex
        mov     r1,r8
        bl      _puthex
        mov     r0,#'\n'
        bl      _putc
        mov     r0,#'\r'
        bl      _putc
        b       00b
 
//
// Write the character in r0
//
_putc:
        ldr     r2,=UART1_BASE_ADDRESS
10:     ldrb    r3,[r2,#UART_STATUS]
        and     r3,r3,#UART_STATUS_TXEMPTY
        cmp     r3,#0
        beq     10b
        strb    r0,[r2,#UART_TXBUF]
        blr
 
//
// Write the string pointed to by r1
//
_puts:
        mov     r7,lr
10:     ldrb    r0,[r1],#1
        cmp     r0,#0
        moveq   pc,r7
        bl      _putc
        b       10b
 
//
// Print the byte in r1 in hex
//
_puthex:
        mov     r7,lr
        mov     r2,r1,lsr #4
        and     r2,r2,#0x0F
        cmp     r2,#0x0A
        addge   r2,r2,#'A'-'0'-0x0A
        add     r0,r2,#'0'
        bl      _putc
        and     r2,r1,#0x0F
        cmp     r2,#0x0A
        addge   r2,r2,#'A'-'0'-0x0A
        add     r0,r2,#'0'
        bl      _putc
        mov     lr,r7
        blr
 
msg:    .string "PC=0x"
 
        .section ".data"
        .align  2
_leds:  .long   0x77
 
        .section ".bss"
_stack_base:
        .rept 512
        .byte 0
        .endr
        .balign 16
_stack:
 
        .end

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Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [rtos/] [ecos-3.0/] [packages/] [hal/] [arm/] [gps4020/] [current/] [support/] [download/] [gps4020_start.S] - Blame information for rev 786

Line No.	Rev	Author	Line
1	786	skrzyp	`//-------------------------------------------------------------------`
2			`//`
3			`// gp4020_start.S`
4			`//`
5			`//-------------------------------------------------------------------`
6			`//`
7			`// Copyright (C) 2003, MLB Associates.`
8			`//`
9			`// This file contains basic startup code for the GPS4020 platform.`
10			`// After initialization, it will call a single "C" function 'main()'`
11			`//`
12			`// Note: this program assumes that it has been downloaded into the`
13			`// on-chip SRAM via the BOOTSTRAP mechanism, so on-chip SRAM is`
14			`// located at address 0x00000000 and external ROM/FLASH is at`
15			`// address 0x60000000`
16			`//`
17
18			`.macro lab,lbl`
19			`.\lbl: .long \lbl`
20			`.endm`
21
22			`.macro blr`
23			`mov pc,lr`
24			`.endm`
25
26			`.equ MPC_BASE_ADDRESS, 0xE0008000`
27			`.equ MPC_AREA1_CONFIG, 0x00000000`
28			`.equ MPC_AREA2_CONFIG, 0x00000004`
29			`.equ MPC_AREA3_CONFIG, 0x00000008`
30			`.equ MPC_AREA4_CONFIG, 0x0000000C`
31			`.equ GPIO_BASE_ADDRESS, 0xE0005000`
32			`.equ GPIO_DIRECTION_REG_OFFSET,0x00000000`
33			`.equ GPIO_READ_REG_OFFSET, 0x00000004`
34			`.equ GPIO_WRITE_REG_OFFSET, 0x00000008`
35			`.equ UART1_BASE_ADDRESS, 0xE0018000`
36			`.equ UART_TXBUF, 0x00000010`
37			`.equ UART_STATUS, 0x0000000C`
38			`.equ UART_STATUS_TXEMPTY, 0x00000002`
39
40			`.text`
41			`.global __exception_handlers`
42			`__exception_handlers:`
43			`b reset // 0x00`
44			`ldr pc,.undefined_instruction // 0x04`
45			`ldr pc,.software_interrupt // 0x08 start && software int`
46			`ldr pc,.abort_prefetch // 0x0C`
47			`ldr pc,.abort_data // 0x10`
48			`.word 0 // unused`
49			`ldr pc,.IRQ // 0x18`
50			`ldr pc,.FIQ // 0x1C`
51
52			`.global vectors`
53			`vectors:`
54			`.long reset // 0x20`
55			`lab undefined_instruction // 0x24`
56			`lab software_interrupt // 0x28`
57			`lab abort_prefetch // 0x2C`
58			`lab abort_data // 0x30`
59			`.word 0 // 0x34`
60			`lab IRQ // 0x38`
61			`lab FIQ // 0x3C`
62
63			`.arm @ AKA ".code32"`
64			`.align 2 @ Align code on 2^2 = 4 byte intervals`
65
66			`.global start`
67			`start:`
68			`reset:`
69
70			`/--------------------------------------------------------------------------/`
71			`// Setup the GPIO and the ARM registers`
72
73			`// make GPIO[0..7] outputs - note: GPIO4 is used for Rx on UART1!`
74
75			`ldr r1,=GPIO_BASE_ADDRESS`
76			`ldr r0, [r1,#GPIO_DIRECTION_REG_OFFSET]`
77			`and r0, r0, #0b00010000 @ 0 = output, 1 = input`
78			`str r0, [r1,#GPIO_DIRECTION_REG_OFFSET] @ Store value (DON'T use strb)`
79
80			`ldr r1,=MPC_BASE_ADDRESS`
81			`ldr r2,=0xFF00002D // 0x6xxxxxxx, 16bit R/W RAM`
82			`str r2,[r1,#MPC_AREA1_CONFIG]`
83
84			`ldr r1,=MPC_BASE_ADDRESS`
85			`ldr r2,=0x00000069 // 0x2xxxxxxx, 16bit R/W RAM`
86			`str r2,[r1,#MPC_AREA2_CONFIG]`
87
88			`ldr r2,[r1,#MPC_AREA3_CONFIG]`
89			`ldr r2,=0x00000021 // 0x4xxxxxxx, 16bit peripheral`
90			`str r2,[r1,#MPC_AREA3_CONFIG]`
91
92			`ldr r2,[r1,#MPC_AREA4_CONFIG]`
93			`ldr r2,=0x0000006E // 0x0xxxxxxx, 32bit memory`
94			`str r2,[r1,#MPC_AREA4_CONFIG]`
95
96			`ldr sp,=_stack`
97			`bl main`
98
99			`10: ldr r1,=GPIO_BASE_ADDRESS`
100			`mov r0,#0`
101			`str r0, [r1,#GPIO_WRITE_REG_OFFSET]`
102			`b 10b`
103
104			`//`
105			`// Exception handlers`
106			`//`
107			`undefined_instruction: // 0x24`
108			`mov r0,#0x24`
109			`b exception`
110			`software_interrupt: // 0x28`
111			`mov r0,#0x28`
112			`b exception`
113			`abort_prefetch: // 0x2C`
114			`mov r0,#0x2C`
115			`b exception`
116			`abort_data: // 0x30`
117			`mov r0,#0x30`
118			`b exception`
119			`IRQ: // 0x38`
120			`mov r0,#0x38`
121			`b exception`
122			`FIQ: // 0x3C`
123			`mov r0,#0x3C`
124			`b exception`
125
126			`exception:`
127			`mov r8,lr // Location of failure`
128			`mov r9,r0`
129			`00:`
130			`ldr r1,=GPIO_BASE_ADDRESS`
131			`str r9, [r1,#GPIO_WRITE_REG_OFFSET]`
132			`ldr r3,=0x100000`
133			`10: nop`
134			`sub r3,r3,#1`
135			`cmp r3,#0`
136			`bne 10b`
137			`str r3,[r1,#GPIO_WRITE_REG_OFFSET]`
138			`ldr r3,=0x80000`
139			`20: nop`
140			`sub r3,r3,#1`
141			`cmp r3,#0`
142			`bne 20b`
143
144			`ldr r1,=msg`
145			`bl _puts`
146			`mov r1,r8,lsr #24`
147			`bl _puthex`
148			`mov r1,r8,lsr #16`
149			`bl _puthex`
150			`mov r1,r8,lsr #8`
151			`bl _puthex`
152			`mov r1,r8`
153			`bl _puthex`
154			`mov r0,#'\n'`
155			`bl _putc`
156			`mov r0,#'\r'`
157			`bl _putc`
158			`b 00b`
159
160			`//`
161			`// Write the character in r0`
162			`//`
163			`_putc:`
164			`ldr r2,=UART1_BASE_ADDRESS`
165			`10: ldrb r3,[r2,#UART_STATUS]`
166			`and r3,r3,#UART_STATUS_TXEMPTY`
167			`cmp r3,#0`
168			`beq 10b`
169			`strb r0,[r2,#UART_TXBUF]`
170			`blr`
171
172			`//`
173			`// Write the string pointed to by r1`
174			`//`
175			`_puts:`
176			`mov r7,lr`
177			`10: ldrb r0,[r1],#1`
178			`cmp r0,#0`
179			`moveq pc,r7`
180			`bl _putc`
181			`b 10b`
182
183			`//`
184			`// Print the byte in r1 in hex`
185			`//`
186			`_puthex:`
187			`mov r7,lr`
188			`mov r2,r1,lsr #4`
189			`and r2,r2,#0x0F`
190			`cmp r2,#0x0A`
191			`addge r2,r2,#'A'-'0'-0x0A`
192			`add r0,r2,#'0'`
193			`bl _putc`
194			`and r2,r1,#0x0F`
195			`cmp r2,#0x0A`
196			`addge r2,r2,#'A'-'0'-0x0A`
197			`add r0,r2,#'0'`
198			`bl _putc`
199			`mov lr,r7`
200			`blr`
201
202			`msg: .string "PC=0x"`
203
204			`.section ".data"`
205			`.align 2`
206			`_leds: .long 0x77`
207
208			`.section ".bss"`
209			`_stack_base:`
210			`.rept 512`
211			`.byte 0`
212			`.endr`
213			`.balign 16`
214			`_stack:`
215
216			`.end`