OK6410串口裸板程序uart0

开发环境
系统：ubuntu 10.04.4
单板：ok6410
编译器：arm-linux-gcc-4.3.2
搭建开发环境详见ubuntu 10.04.4开发环境配置。
目标：实现ok6410 uart0 显示任意输入字符

一、编写源代码

根据s3c6410手册编写代码，包括源文件start.S clock.S main.c uart.c uart.h lib.c lib.h Makefile

文件start.S:

.globl _start_start:/* 硬件相关的设置 */    /* Peri port setup */    ldr r0, =0x70000000    orr r0, r0, #0x13    mcr p15,0,r0,c15,c2,4       @ 256M(0x70000000-0x7fffffff)    /* 关看门狗 *//* 往WTCON(0x7E004000)写0 */ldr r0, =0x7E004000mov r1, #0str r1, [r0]/* 设置栈 */ldr sp, =8*1024/* 设置时钟 */bl clock_initbl mainhalt:b halt

文件clock.S:

.globl clock_initclock_init:/* 1.设置LOCK_TIME */ldr r0, =0x7E00F000  /* APLL_LOCK */ldr r1, =0x0000FFFFstr r1, [r0]str r1, [r0, #4] /* MPLL_LOCK */str r1, [r0, #8] /* EPLL_LOCK */#define OTHERS0x7e00f900@ set async mode  /* 当CPU时钟 != HCLK时，要设为异步模式 */ldr r0, =OTHERSldr r1, [r0]bic r1, #0xc0str r1, [r0]loop1:/* 等待，直到CPU进入异步模式 */ldr r0, =OTHERSldr r1, [r0]and r1, #0xf00cmp r1, #0bne loop1/* SYNC667 *//* MISC_CON[19] = 0 */#define ARM_RATIO    0   /* ARMCLK = DOUTAPLL / (ARM_RATIO + 1)    */#define HCLKX2_RATIO 1   /* HCLKX2 = HCLKX2IN / (HCLKX2_RATIO + 1) */#define HCLK_RATIO   1   /* HCLK = HCLKX2 / (HCLK_RATIO + 1)       */#define PCLK_RATIO   3   /* PCLK   = HCLKX2 / (PCLK_RATIO + 1)     */#define MPLL_RATIO   0   /* DOUTMPLL = MOUTMPLL / (MPLL_RATIO + 1)     */ldr r0, =0x7E00F020  /* CLK_DIV0 */ldr r1, =(ARM_RATIO) | (MPLL_RATIO << 4) | (HCLK_RATIO << 8) | (HCLKX2_RATIO << 9) | (PCLK_RATIO << 12)str r1, [r0]/* 2.配置时钟 *//* 2.1 配置APLL *//* 2.1.1 设置APLL * 2.1.2 MUXAPLL * 2.1.3 SYNC667 * 2.1.4 DIVAPLL */#define APLL_CON_VAL  ((1<<31) | (266 << 16) | (3 << 8) | (1))ldr r0, =0x7E00F00Cldr r1, =APLL_CON_VALstr r1, [r0]/* APLL_CON, FOUTAPL = MDIV * Fin / (PDIV*2^SDIV) = 266*12/(3*2^1) = 532MHz  *//* 2.2 配置MPLL *//* 2.2.1 设置MPLL * 2.2.2 MUXMPLL * 2.2.3 SYNCMUX * 2.2.4 SYNC667 * 2.2.5 HCLKX2_RATIO * 2.2.6 PCLK_RATIO */#define MPLL_CON_VAL  ((1<<31) | (266 << 16) | (3 << 8) | (1))ldr r0, =0x7E00F010ldr r1, =MPLL_CON_VALstr r1, [r0]/* MPLL_CON, FOUTMPL = MDIV * Fin / (PDIV*2^SDIV) = 266*12/(3*2^1) = 532MHz  *//* 3.选择PLL的输出作为时钟源 */ldr r0, =0x7E00F01Cldr r1, =0x03str r1, [r0]mov pc, lr

文件main.c:

#include "uart.h"#include "lib.h"int main(){char c;uart_init();  while(1)    {        // 从串口接收数据后，判断其是否数字或子母，若是则加1后输出 do {c = getc();if (c == '\n' || c == '\r')  {   putc('\n');putc('\r');  }else  {    putc(c);  }      } while (c == '\n' || c == '\r');   }return 0;}

文件uart.c:

#define ULCON0     (*((volatile unsigned long *)0x7F005000))#define UCON0      (*((volatile unsigned long *)0x7F005004))#define UFCON0     (*((volatile unsigned long *)0x7F005008))#define UMCON0     (*((volatile unsigned long *)0x7F00500C))#define UTRSTAT0   (*((volatile unsigned long *)0x7F005010))#define UFSTAT0    (*((volatile unsigned long *)0x7F005018))#define UTXH0      (*((volatile unsigned char *)0x7F005020))#define URXH0      (*((volatile unsigned char *)0x7F005024))#define UBRDIV0    (*((volatile unsigned short *)0x7F005028))#define UDIVSLOT0  (*((volatile unsigned short *)0x7F00502C))#define GPACON     (*((volatile unsigned long *)0x7F008000))void uart_init(void){GPACON &= ~0xff;GPACON |= 0x22;/* ULCON0 */ULCON0 = 0x3;  /* 数据位:8, 无较验, 停止位: 1, 8n1 */UCON0  = 0x5;  /* 使能UART发送、接收 */UFCON0 = 0x01; /* FIFO ENABLE */UMCON0 = 0;/* 波特率 *//* DIV_VAL = (PCLK / (bps x 16 ) ) - 1  * bps = 57600 * DIV_VAL = (66500000 / (115200 x 16 ) ) - 1  *         = 35.08 */UBRDIV0   = 35;/* x/16 = 0.08 * x = 1 */UDIVSLOT0 = 0x1;}

文件uart.h:

void uart_init(void);

文件lib.c:

#define UFSTAT0    (*((volatile unsigned long *)0x7F005018))#define UTXH0      (*((volatile unsigned char *)0x7F005020))#define URXH0      (*((volatile unsigned char *)0x7F005024))char getc(void){while ((UFSTAT0 & (1<<6)) == 0 && (UFSTAT0 & 0x3f) == 0);return URXH0;}void putc(char c){while (UFSTAT0 & (1<<14));UTXH0 = c;}

文件lib.h:

void putc(char c);char getc(void);

文件Makefile:

2_uart.bin: start.o clock.o main.o uart.o lib.oarm-linux-ld -Ttext 0x52000000 -o uart.elf $^arm-linux-objcopy -O binary uart.elf 2_uart.binarm-linux-objdump -D uart.elf > uart.dis%.o : %.Sarm-linux-gcc -o $@ $< -c%.o : %.carm-linux-gcc -o $@ $< -cclean:rm *.o uart.elf *.bin uart.dis

二、编译

编译后将生成的2_uart.bin拷到ubuntu 的tftp目录下，tftp配置详见ubuntu 10.04.4开发环境配置

change@change:~$ cd Si/OK6410/2_uart0/
change@change:~/Si/OK6410/2_uart0$ ls
clock.S  lib.c  lib.h  main.c  Makefile  start.S  uart.c  uart.h
change@change:~/Si/OK6410/2_uart0$ make
arm-linux-gcc -o start.o start.S -c
arm-linux-gcc -o clock.o clock.S -c
arm-linux-gcc -o main.o main.c -c
In file included from main.c:3:
lib.h:1: warning: conflicting types for built-in function 'putc'
arm-linux-gcc -o uart.o uart.c -c
arm-linux-gcc -o lib.o lib.c -c
lib.c:12: warning: conflicting types for built-in function 'putc'
arm-linux-ld -Ttext 0x52000000 -o uart.elf start.o clock.o main.o uart.o lib.o
arm-linux-objcopy -O binary uart.elf 2_uart.bin
arm-linux-objdump -D uart.elf > uart.dis
change@change:~/Si/OK6410/2_uart0$ ls
2_uart.bin  clock.S  lib.h  main.c  Makefile  start.S  uart.dis  uart.h
clock.o     lib.c    lib.o  main.o  start.o   uart.c   uart.elf  uart.o
change@change:~/Si/OK6410/2_uart0$ cp 2_uart.bin /home/change/work/tftpboot/

三、烧写测试

我的单板ok6410中有NAND flash，没有NOR flash。考虑到大多数电脑没有并口，也没有编程器，我用u-boot下载程序到内存运行。但是单板的u-boot要支持网卡。

以后会写一个操作NAND的自我更新程序的，到时下载程序就方便了。

单板上电：

U-Boot 2012.04.01 (Jan 11 2013 - 14:47:24) for SMDK6410

CPU:     S3C6400@532MHz
         Fclk = 532MHz, Hclk = 133MHz, Pclk = 66MHz (ASYNC Mode) 
Board:   SMDK6410
DRAM:  128 MiB
WARNING: Caches not enabled
Flash: 0 KB
NAND:  select s3c_nand_oob_mlc_64
id_data[0] = 0xec id_data[1] = 0xd5 id_data[2] = 0x94 id_data[3] = 0x29 id_data[4] = 0x34 id_data[5] = 0x41 id_data[6] = 0xec id_data[7] = 0xd5 NAND_ECC_NONE selected by board driver. This is not recommended !!
2048 MiB
realpage value:255
page value:255
ret value:0
In:    serial
Out:   serial
Err:   serial
Net:   dm9000
Hit any key to stop autoboot:  0 

##### 100ask Bootloader for OpenJTAG #####
[n] Download u-boot to Nand Flash
[k] Download Linux kernel uImage
[j] Download root_jffs2 image
[y] Download root_yaffs image
[d] Download to SDRAM & Run
[z] Download zImage into RAM
[g] get file, and write to nand flash 0 block
[f] Format the Nand Flash
[s] Set the boot parameters
[b] Boot the system
[r] Reboot u-boot
[q] Quit from menu
Enter your selection: q
SMDK6410 # printenv
baudrate=115200
bootargs=console=ttySAC0,115200 root=/dev/mtdblock3
bootcmd=nand read 0x50000000 0x60000 0x200000;bootm 0x50000000
bootdelay=5
ethact=dm9000
ethaddr=00:0c:29:4d:e4:f4
gatewayip=172.16.1.1
ipaddr=172.16.1.133
netmask=255.255.255.0
serverip=172.16.1.135
stderr=serial
stdin=serial
stdout=serial

Environment size: 336/524284 bytes
SMDK6410 # ping 172.16.1.135
dm9000 i/o: 0x18000000, id: 0x90000a46 
DM9000: running in 16 bit mode
MAC: 00:0c:29:4d:e4:f4
operating at 100M full duplex mode
Using dm9000 device
host 172.16.1.135 is alive
SMDK6410 # tftp 0x52000000 2_uart.bin
dm9000 i/o: 0x18000000, id: 0x90000a46 
DM9000: running in 16 bit mode
MAC: 00:0c:29:4d:e4:f4
operating at 100M full duplex mode
Using dm9000 device
TFTP from server 172.16.1.135; our IP address is 172.16.1.133
Filename '2_uart.bin'.
Load address: 0x52000000
Loading: #
done
Bytes transferred = 664 (298 hex)

下面开始测试uart程序，在u-boot输入命令go 0x52000000，程序便开始运行，并且是一去不复返
SMDK6410 # go 0x52000000
## Starting application at 0x52000000 ...

此时输入任意字符，测试OK

adfsdQWDF
midfakd3148
ok6410 test
it's ok!