von
michael (Guest)
2010-02-14 11:07
Dear all
I am a beginner with ARM. I use mini2440 board with s3c2440
microcontroller. My problem is that I can't find fitting startup for
this ARM, which configure all devices.
I would like use timer with interrupt but it doesn't work.
I found somewhere this startup:
1 . global vectors
2 vectors :
3 b start
4 b undef_instr_handler
5 b software_int_handler
6 b prefetch_abort_handler
7 b data_abort_handler
8 b reserved_handler
9 b irq_handler
10 b fiq_handler
11
12
13 start :
14 /* enter supervisor mode, disable IRQ */
15 msr cpsr , # 0xd3
16
17 /* Disable the watchdog */
18 ldr r2 , = 0x00000000
19 mov r1 , # 0x53000000
20 str r2 , [ r1 ]
21
22 /* Mask all Interupts to be safe */
23 ldr r2 , = 0xFFFFFFFF
24 mov r1 , # 0x4A000000
25 str r2 , [ r1 , # 0x08 ]
26
27 /* Set up stack for IRQ mode */
28 msr cpsr_c , # 0xd2
29 ldr sp , = irq_stack
30
31 /* Set up stack for FIQ mode */
32 msr cpsr_c , # 0xd1
33 ldr sp , = fiq_stack
34
35 /* Let abort and undefined modes use IRQ stack */
36 msr cpsr_c , # 0xd7
37 ldr sp , = irq_stack
38 msr cpsr_c , # 0xdb
39 ldr sp , = irq_stack
40
41 /* Switch to supervisor mode */
42 msr cpsr_c , # 0xd3
43 ldr sp , = stackend
44
45 /* Start the main function */
46 adr lr , vectors
47 ldr pc , = main
48
49
50 undef_instr_handler :
51 mov r0 , lr
52 mov r1 , # 0
53 b UIE
54
55 software_int_handler :
56 reserved_handler :
57 movs pc , lr
58
59 prefetch_abort_handler :
60 sub r0 , lr , # 4
61 mov r1 , # 1
62 b UIE
63
64 data_abort_handler :
65 sub r0 , lr , # 8
66 mov r1 , # 2
67 b UIE
68
69 irq_handler :
70 bl UIE
71
72 fiq_handler :
73 b UIE
74
75 UIE :
76 b UIE
77
78 irq_stack :
79 . word 0x0badc0de
80
81 fiq_stack :
82 . word 0x0badc0de
83 end :
My C code: 1 /******************************************************************************
2 * timer.c
3 * chip: s3c2440
4 * compiler: arm-none-eabi-gcc 4.3.3
5 *
6 * Created on: 2010-02-04
7 * Author: michal grzybek
8 *
9 * This code shows how use timers to count time with interrupts.
10 * There is used timer no. 2
11 * to count one second. After this time is enable binary counter on LED's
12 ******************************************************************************/
13
14
15 #include "2440addr.h"
16 #include "Def.h"
17
18 void init_timer ( void );
19 void binary_leds ( void );
20
21
22 void timer_handler ( void ) __attribute__ (( interrupt ( "IRQ" )));
23 void timer_handler ( void )
24 {
25
26 ClearPending ( BIT_TIMER2 );
27 binary_leds ();
28
29 }
30
31
32 U16 i = 0 , tmp = 0 ; /* temporary needed to binary counter*/
33
34 int main ( void )
35 {
36
37 init_timer ();
38
39 while ( 1 );
40
41
42
43 return 0 ;
44 }
45
46 void init_timer ( void )
47 {
48 pISR_TIMER2 = ( unsigned ) timer_handler ; /* address of interrupt service routine*/
49 pISR_IRQ = ( unsigned ) timer_handler ;
50 ClearPending ( BIT_TIMER2 ); /* interrupt timer2 requested*/
51 EnableIrq ( BIT_TIMER2 ); /* */
52
53
54 rGPBCON &= 0xffffcc ; /* mask GPBCON and clear 5th and 4th bits and buzzer off*/
55 rGPBCON |= 0x000020 ; /* set 5th and 4th bits at 2 binary value,
56 //it's mean that GPB2 is configured as TOUT2*/
57
58 rGPBCON &= 0xfc03ff ; /*Port GPB is configured for leds (GPB5,GPB6,GPB7,GPB8-output)*/
59 rGPBCON |= 0x0015400 ;
60
61 rGPBDAT |= 0x1e0 ; /*LEDs are cleared*/
62
63 rTCFG0 |= 0x0ff00 ; /* prescaler configured as 255 value*/
64 rTCFG1 |= 0x00300 ; /* divider configured as 16 value */
65
66
67 /******************* timer on ***************************/
68 rTCMPB2 = 0 ; /* set comparator at 0*/
69 rTCNTB2 = 65000 ; /* set counter to count 1 sec */
70 rTCON = 0x00a000 ; /* Auto-reload is on, manual update bit is set*/
71 rTCON = 0x009000 ; /* manual update bit is cleared, start bit is set */
72
73 }
74
75
76 void binary_leds ( void )
77 {
78
79
80 tmp ++ ;
81 i = tmp ;
82 i = ( ~ i ) << 5 ;
83
84 rGPBDAT |= 0x1e0 ;
85 rGPBDAT &= i ;
86 }
Your start-up looks rather too minimal for an ARM9; you have no set-up
for PLL, MMU, Cache, or SDRAM controller; or do you have a bootloader
that is doing all that for you?
The http://www.friendlyarm.net/downloads page has a uCOS-II port
download that includes start-up code that is probably closer to your
requirements, even if you do not actually need the uCOS-II stuff.
von
michael (Guest)
2010-02-18 18:34
Ok, I downloaded uCOS-II but there is startup for ADS. I use gcc and
this file doesn't fit.
Any idea?
von
Andreas (Guest)
2010-03-02 19:55
port the files to GCC or have a look at the RT-Thread project:
http://code.google.com/p/rt-thread/
This was discussed a while ago here: http://embdev.net/topic/146188
The Micrium site has generic ARM ports for GCC; they just don't make it
too obvious where! The thread I mentioned tells you how.
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