文件1.head.s
@ 文件 head.s
@ 作用:關閉看門狗、SDRAM 的初始化設置、搬移 Nand Flash 4K 以後
@ 的代碼到 SDRAM 的指定位置、執行 SDRAM 中的代碼
.text
.global _start
_start:
ldr r0, =0x53000000 @ Close Watch Dog Timer
mov r1, #0x0
str r1, [r0]
bl memory_setup @ Initialize memory setting
bl flash_to_sdram @ Copy code to sdram
ldr sp, =0x34000000 @ Set stack pointer
ldr pc, =main @ execute the code in SDRAM
文件2：flash.s
@ 文件 flash.s
@ 作用:設置 Nand Flash 的控制寄存器、讀取 Nand Flash
@ 中的代碼到 SDRAM 的指定位置
.equ NFCONF, 0x4e000000
.equ NFCMD, 0x4e000004
.equ NFADDR, 0x4e000008
.equ NFDATA, 0x4e00000c
.equ NFSTAT, 0x4e000010
.equ NFECC, 0x4e000014
.global flash_to_sdram
flash_to_sdram:
@ Save return addr
mov r10,lr
@ Initialize Nand Flash
mov r0,#NFCONF
ldr r1,=0xf830
str r1,[r0]
@ First reset and enable Nand Flash
ldr r1,[r0]
bic r1, r1, #0x800
str r1,[r0]
ldr r2,=NFCMD
mov r3,#0xff
str r3,[r2]
@ for delay
mov r3, #0
1:
subs r3, r3, #1
bne 1b
@ Wait until Nand Flash bit0 is 1
wait_nfstat:
ldr r2,=NFSTAT
ldr r3,[r2]
tst r3,#0x01
beq wait_nfstat
@ Disable Nand Flash
ldr r0,=NFCONF
ldr r1,[r0]
orr r1,r1,#0x8000
str r1,[r0]
@ Initialzie stack
ldr sp,=4096
@ Set arguments and call
@ function nand_read defined in nand_read.c
ldr r0,=0x30000000
mov r1,#4096
mov r2,#1024
bl nand_read
@ return
mov pc,r10
文件3：interrupt.c
/*
* 文件 interrupt.c
* 作用:設置並響應按鍵中斷
*/
#include "printf.h"
#define GPECON (*(volatile unsigned long *)0x56000040)
#define GPEDAT (*(volatile unsigned long *)0x56000044)
#define GPEUP (*(volatile unsigned long *)0x56000048)
#define GPFCON (*(volatile unsigned long *)0x56000050)
#define GPFDAT (*(volatile unsigned long *)0x56000054)
#define GPFUP (*(volatile unsigned long *)0x56000058)
#define GPGCON (*(volatile unsigned long *)0x56000060)
#define GPGDAT (*(volatile unsigned long *)0x56000064)
#define GPGUP (*(volatile unsigned long *)0x56000068)
#define EINTMASK (*(volatile unsigned long *)0x560000a4)
#define INTMSK (*(volatile unsigned long *)0X4a000008)
#define PRIORITY (*(volatile unsigned long *)0x4a00000c)
#define EINTPEND (*(volatile unsigned long *)0x560000a8)
#define INTPND (*(volatile unsigned long *)0X4a000010)
#define SRCPND (*(volatile unsigned long *)0X4a000000)
#define BIT_EINT0 (0x1 << 0)
#define BIT_EINT2 (0x1 << 2)
#define BIT_EINT8_23 (0x1 << 5)
#define SET_KEY_INTERRUPT_REG() ({ \
GPGCON = (GPGCON & (~((3<<12)|(3<<4)))) | ((1<<12)|(1<<4)) ; \
GPGDAT = GPGDAT & (~((1<<6)|(1<<2))); \
GPECON = (GPECON & (~((3<<26)|(3<<22)))) | ((1<<26)|(1<<22)); \
GPEDAT = GPEDAT & (~((1<<13)|(1<<11))); \
GPGCON = (GPGCON & (~((3<<22)|(3<<6)))) | ((2<<22)|(2<<6)) ; \
GPFCON = (GPFCON & (~((3<<4)|(3<<0)))) | ((2<<4)|(2<<0)) ; \
})
__inline void ClearPending(int bit)
{
SRCPND = bit;
INTPND = bit;
}
void init_irq( ) {
GPFCON = ((0x1<<8) | (0x1 << 10) | (0x1 << 12) | (0x1 << 14)); // Set the led D9~D12 output
/*
GPGCON = (GPGCON & (~((3<<12)|(3<<4)))) | ((1<<12)|(1<<4)) ; // GPGCON6,2 set output
// GPGCON6:KSCAN1
// GPGCON2:KSCAN3
GPGDAT = GPGDAT & (~((1<<6)|(1<<2))); // GPGDAT6,2 output 0
GPECON = (GPECON & (~((3<<26)|(3<<22)))) | ((1<<26)|(1<<22)); // GPECON13,11 set output
GPEDAT = GPEDAT & (~((1<<13)|(1<<11))); // GPEDAT13,11 output 0
GPGCON = (GPGCON & (~((3<<22)|(3<<6)))) | ((2<<22)|(2<<6)) ; // GPGCON11,3 set EINT
GPFCON = (GPFCON & (~((3<<4)|(3<<0)))) | ((2<<4)|(2<<0)) ; // GPFDAT2,0 set EINT
*/
// Use the defined micro instead of above code
SET_KEY_INTERRUPT_REG();
GPFUP |= (1<<0) | (1<<2); // Up
GPGUP |= (1<<3) | (1<<11); // Up
EINTPEND |= (1 << 19) | (1 << 11); // Clear eint 11,19
EINTMASK &= (~((1 << 19) | (1 << 11))); // Enable EINT11,19
ClearPending(BIT_EINT0|BIT_EINT2|BIT_EINT8_23); // Enable EINT0,2 and the EINT8_23
INTMSK &= (~0x25);
return;
}
int Key_Scan( void )
{
int i;
for(i = 0; i < 1000 ;i++) ;
GPGDAT = (GPGDAT &(~((1<<6)|(1<<2)))) | (1<<6) | (0<<2) ; //GPG6,2 output 0
GPEDAT = (GPEDAT &(~((1<<13)|(1<<11)))) | (1<<13) | (1<<11) ; //GPE13,11 output 0
if( (GPFDAT&(1<< 0)) == 0 ) return 16 ;
else if( (GPFDAT&(1<< 2)) == 0 ) return 15 ;
else if( (GPGDAT&(1<< 3)) == 0 ) return 14 ;
else if( (GPGDAT&(1<<11)) == 0 ) return 13 ;
GPGDAT = (GPGDAT &(~((1<<6)|(1<<2)))) | (0<<6) | (1<<2) ; //GPG6,2 output 0
GPEDAT = (GPEDAT & (~((1<<13)|(1<<11)))) | (1<<13) | (1<<11) ; //GPE13,11 output 0
if( (GPFDAT&(1<< 0)) == 0 ) return 11 ;
else if( (GPFDAT&(1<< 2)) == 0 ) return 8 ;
else if( (GPGDAT&(1<< 3)) == 0 ) return 5 ;
else if( (GPGDAT&(1<<11)) == 0 ) return 2 ;
GPGDAT = (GPGDAT & (~((1<<6)|(1<<2)))) | (1<<6) | (1<<2) ; //GPG6,2 output 0
GPEDAT = (GPEDAT & (~((1<<13)|(1<<11)))) | (1<<13) | (0<<11) ; //GPE13,11 output 0
if( (GPFDAT&(1<< 0)) == 0 ) return 10 ;
else if( (GPFDAT&(1<< 2)) == 0 ) return 7 ;
else if( (GPGDAT&(1<< 3)) == 0 ) return 4 ;
else if( (GPGDAT&(1<<11)) == 0 ) return 1 ;
GPGDAT = (GPGDAT & (~((1<<6)|(1<<2)))) | (1<<6) | (1<<2) ; //GPG6,2 output 0
GPEDAT = (GPEDAT & (~((1<<13)|(1<<11)))) | (0<<13) | (1<<11) ; //GPE13,11 output 0
if( (GPFDAT&(1<< 0)) == 0 ) return 12 ;
else if( (GPFDAT&(1<< 2)) == 0 ) return 9 ;
else if( (GPGDAT&(1<< 3)) == 0 ) return 6 ;
else if( (GPGDAT&(1<<11)) == 0 ) return 3 ;
else return 0xff ;
}
void EINT_Handle( void ) {
GPGCON = (GPGCON & (~((3<<22)|(3<<6)))) | ((0<<22)|(0<<6)) ; //GPG11,3 set input
GPFCON = (GPFCON & (~((3<<4)|(3<<0)))) | ((0<<4)|(0<<0)) ; //GPF2, 0 set input
if(INTPND==BIT_EINT8_23) {
if(EINTPEND&(1<<11))
EINTPEND |= 1<< 11;
if(EINTPEND&(1<<19))
EINTPEND |= 1<< 19;
ClearPending(BIT_EINT8_23);
}
else if(INTPND==BIT_EINT0) {
ClearPending(BIT_EINT0);
} else if(INTPND==BIT_EINT2) {
ClearPending(BIT_EINT2);
}
int key = Key_Scan() ;
if( key != 0xff ) {
uart_printf( "K%d is pressed!\n", key ) ;
GPFDAT = ~(key << 4);
}
SET_KEY_INTERRUPT_REG();
return;
}
文件4：mem.s
@ 文件 mem.s
@ 作用:SDRAM 的初始化設置
@ 關於初始化的更多細節，請參考我的前壹篇隨筆
.global memory_setup @ 導出 memory_setup, 使其對鏈接器可見
memory_setup:
mov r1, #0x48000000
adrl r2, mem_cfg_val
add r3, r1, #13*4
1:
@ write initial values to registers
ldr r4, [r2], #4
str r4, [r1], #4
cmp r1, r3
bne 1b
mov pc, lr
.align 4
mem_cfg_val:
.long 0x22111110 @ BWSCON
.long 0x00000700 @ BANKCON0
.long 0x00000700 @ BANKCON1
.long 0x00000700 @ BANKCON2
.long 0x00000700 @ BANKCON3
.long 0x00000700 @ BANKCON4
.long 0x00000700 @ BANKCON5
.long 0x00018005 @ BANKCON6
.long 0x00018005 @ BANKCON7 9bit
.long 0x008e07a3 @ REFRESH
.long 0x000000b2 @ BANKSIZE
.long 0x00000030 @ MRSRB6
.long 0x00000030 @ MRSRB7
文件5：nand_read.c
/* 文件 nand_read.c
* 作用:從 Nand Flash 中讀取壹塊數據到 SDRAM 中的指定位置
*/
#define NFCONF (*(volatile unsigned long *)0x4e000000)
#define NFCMD (*(volatile unsigned long *)0x4e000004)
#define NFADDR (*(volatile unsigned long *)0x4e000008)
#define NFDATA (*(volatile unsigned long *)0x4e00000c)
#define NFSTAT (*(volatile unsigned long *)0x4e000010)
#define NFECC (*(volatile unsigned long *)0x4e000014)
#define NAND_SECTOR_SIZE 512
#define NAND_BLOCK_MASK 0x1ff
void wait_idle() {
int i;
for (i = 0; i < 50000; ++i) ;
}
int nand_read(unsigned char *buf, unsigned long start_addr, int size){
int i, j;
/*
* detect the argument
*/
if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) {
return -1;
}
/* chip Enable */
NFCONF &= ~0x800;
for (i=0; i<10; i++) {
;
}
for (i=start_addr; i < (start_addr + size); i+=NAND_SECTOR_SIZE) {
NFCMD = 0;
/* Write Address */
NFADDR = i & 0xff;
NFADDR = (i >> 9) & 0xff;
NFADDR = (i >> 17) & 0xff;
NFADDR = (i >> 25) & 0xff;
wait_idle();
for(j=0; j < NAND_SECTOR_SIZE; j++) {
*buf++ = (NFDATA & 0xff);
}
}
NFCONF |= 0x800; /* chip disable */
return 0;
}
文件6：sdram.c
/* 文件 sdram.c
* 作用:循環點 FS2410 開發板上的 D9、D10、D11、D12
* 四個發光二極管。
*/
#define GPFCON (*(volatile unsigned long *)0x56000050)
#define GPFDAT (*(volatile unsigned long *)0x56000054)
int main()
{
int i,j;
while(1) {
for (i = 0; i <4; ++i) {
GPFCON = 0x1<<(8+i*2);
GPFDAT = 0x0;
// for delay
for(j=0;j<50000;++j) ;
}
}
}
文件7：nand.lds
SECTIONS {
first 0x00000000 : { head.o mem.o flash.o nand_read.o }
second 0x30000000 : AT(4096) { sdram.o }
}
文件8：Makefile
sdram:head.s flash.s mem.s sdram.c
arm-linux-gcc -c -o head.o head.s
arm-linux-gcc -c -o mem.o mem.s
arm-linux-gcc -c -o flash.o flash.s
arm-linux-gcc -c -o nand_read.o nand_read.c
arm-linux-gcc -c -o sdram.o sdram.c
arm-linux-ld -Tnand.lds head.o mem.o flash.o nand_read.o sdram.o -o sdram_tmp.o
arm-linux-objcopy -O binary -S sdram_tmp.o sdram
clean:
rm -f *.o
rm -f sdram
好了，妳把這些文件拷下去，執行make命令就能生成可執行的二進制代碼sdram，把sdram燒寫到板子上就能運行了。祝妳好運