Zynq-Linux移植学习笔记之17-Zynq下linuxPL部分Flash

 

1、  背景介绍

在板上，ZYNQ PL部分通过EMC连接一片NOR FLASH，地址空间如下：



可以看到NOR FLASH的起始地址为0x80000000，这是物理地址，可以把数据存放在以该地址起始的一段区域。

需要注意的是，在对NOR FLASH进行读写数据时，需要参考对应的datasheet，例如这里选用的NOR FLASH读、写、擦除步骤如下：









通过上面的表格就知道进行相应操作每一步该做什么，可以转换为SDK中裸奔程序的C代码。

 

2、  Linux下flash操作

之前提到过zynq中Linux用户应用程序可以通过/dev/mem访问到物理地址，xil_in32和xil_out32等裸奔程序中常见的函数可以通过这一机制移植到linux下。于是，对flash的操作其实就是基于xil_in和xil_out对物理地址进行读写。

这里只需要实现三个函数，erase，write_sector以及read_sector.代码如下：

 //xil_io.h

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>

#include <unistd.h>
#include <fcntl.h>

#define PAGE_SIZE ((size_t)getpagesize())
#define PAGE_MASK ((uint64_t) (long)~(PAGE_SIZE - 1))

void Xil_Out32(uint64_t phyaddr, uint32_t val)
{
int fd;
volatile uint8_t *map_base;
uint64_t base = phyaddr & PAGE_MASK;
uint64_t pgoffset = phyaddr & (~PAGE_MASK);

if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1)
{
perror("open /dev/mem:");
}

map_base = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
fd, base);
if(map_base == MAP_FAILED)
{
perror("mmap:");
}
*(volatile uint32_t *)(map_base + pgoffset) = val;
close(fd);
munmap((void *)map_base, PAGE_SIZE);
}

int Xil_In32(uint64_t phyaddr)
{
int fd;
uint32_t val;
volatile uint8_t *map_base;
uint64_t base = phyaddr & PAGE_MASK;
uint64_t pgoffset = phyaddr & (~PAGE_MASK);
//open /dev/mem
if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1)
{
perror("open /dev/mem:");
}
//mmap
map_base = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
fd, base);
if(map_base == MAP_FAILED)
{
perror("mmap:");
}
val = *(volatile uint32_t *)(map_base + pgoffset);
close(fd);
munmap((void *)map_base, PAGE_SIZE);

return val;
}

void Xil_Out16(uint64_t phyaddr, uint16_t val)
{
int fd;
volatile uint8_t *map_base;
uint64_t base = phyaddr & PAGE_MASK;
uint64_t pgoffset = phyaddr & (~PAGE_MASK);

if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1)
{
perror("open /dev/mem:");
}

map_base = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
fd, base);
if(map_base == MAP_FAILED)
{
perror("mmap:");
}
*(volatile uint16_t *)(map_base + pgoffset) = val;
close(fd);
munmap((void *)map_base, PAGE_SIZE);
}

int Xil_In16(uint64_t phyaddr)
{
int fd;
uint16_t val;
volatile uint8_t *map_base;
uint64_t base = phyaddr & PAGE_MASK;
uint64_t pgoffset = phyaddr & (~PAGE_MASK);
//open /dev/mem
if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1)
{
perror("open /dev/mem:");
}
//mmap
map_base = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
fd, base);
if(map_base == MAP_FAILED)
{
perror("mmap:");
}
val = *(volatile uint16_t *)(map_base + pgoffset);
close(fd);
munmap((void *)map_base, PAGE_SIZE);

return val;
}

void Xil_Out8(uint64_t phyaddr, uint16_t val)
{
int fd;
volatile uint8_t *map_base;
uint64_t base = phyaddr & PAGE_MASK;
uint64_t pgoffset = phyaddr & (~PAGE_MASK);

if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1)
{
perror("open /dev/mem:");
}

map_base = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
fd, base);
if(map_base == MAP_FAILED)
{
perror("mmap:");
}
*(volatile uint8_t *)(map_base + pgoffset) = val;
close(fd);
munmap((void *)map_base, PAGE_SIZE);
}

int Xil_In8(uint64_t phyaddr)
{
int fd;
uint8_t val;
volatile uint8_t *map_base;
uint64_t base = phyaddr & PAGE_MASK;
uint64_t pgoffset = phyaddr & (~PAGE_MASK);
//open /dev/mem
if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1)
{
perror("open /dev/mem:");
}
//mmap
map_base = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
fd, base);
if(map_base == MAP_FAILED)
{
perror("mmap:");
}
val = *(volatile uint8_t *)(map_base + pgoffset);
close(fd);
munmap((void *)map_base, PAGE_SIZE);

return val;
}

 //move.h

#ifndef SMARTCARMOVE_H
#define SMARTCARMOVE_H

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <syslog.h>
#include <memory.h>

static int fd;

#define MODE (O_WRONLY | O_TRUNC)

#define SECSIZE 65536
#define XPAR_AXI_EMC_0_S_AXI_MEM0_BASEADDR 0x80000000
#define WAIT_TICKS 0xffffffff

typedef unsigned short u16;

extern void flash_set16(unsigned int addrBase,unsigned int addrOffset,unsigned int value);
extern int flash_get16(unsigned int addrBase,unsigned int addrOffset);

extern int Erase_Flash(int sectorNum);
extern int Write_Sector(int sectorNum,int offset,u16 *src_addr,int wr_num);
extern int Read_Sector(int sectorNum,int rd_num,unsigned short *buf);

#endif

 #include "xil_io.h"
#include "move.h"

/**
read and write phy mem
* */
void flash_set16(unsigned int addrBase,unsigned int addrOffset,unsigned int value)
{
Xil_Out16(addrBase+2*addrOffset, value);
//printf("flash set reg 0x%x value is 0x%x\n",addrBase+2*addrOffset,value);
}

int flash_get16(unsigned int addrBase,unsigned int addrOffset)
{
int ans=0;
ans=Xil_In16(addrBase+2*addrOffset);
return ans;
}

int Erase_Flash(int sectorNum)
{
unsigned short flag;
int i=0;
int val=0;
unsigned short *base_addr;
base_addr = (unsigned short*)(XPAR_AXI_EMC_0_S_AXI_MEM0_BASEADDR+SECSIZE*sectorNum*2);
printf("erase start addr 0x%x\n",base_addr);

flash_set16(base_addr,0x555,0x00AA);
flash_set16(base_addr,0x2AA,0x0055);
flash_set16(base_addr,0x555,0x0080);
flash_set16(base_addr,0x555,0x00AA);
flash_set16(base_addr,0x2AA,0x0055);
flash_set16(base_addr,0,0x0030);

val=flash_get16(base_addr,0);
printf("base addr 0x%x val is 0x%x\n",base_addr,val);

while((val&0x80)!=0x80)
{
i++;
if( i>=WAIT_TICKS)
{
printf("addr %x Erase_Flash failed!\n",base_addr);
flash_set16(base_addr,0x555,0x0090);
flash_set16(base_addr,0x000,0x0000);
return -1;
}
//flag = base_addr;
val=flash_get16(base_addr,0);
}
flash_set16(base_addr,0x555,0x0090);
flash_set16(base_addr,0x000,0x0000);

printf("erase end addr %x\n",base_addr+SECSIZE);
return 0;
}

int Write_Sector(int sectorNum,int offset,u16 *src_addr,int wr_num)
{
int i,j;
u16 *dst_addr;
int val=0;
int ans=0;
dst_addr = (u16*)(XPAR_AXI_EMC_0_S_AXI_MEM0_BASEADDR+SECSIZE*sectorNum*2+offset);

/* Unlock Bypass program */

flash_set16(dst_addr,0x555,0x00AA);
flash_set16(dst_addr,0x2AA,0x0055);

printf("dst addr is 0x%x\n",dst_addr);
for(i=0;i<wr_num;i++)
{

flash_set16(dst_addr,0x555,0x0020);
flash_set16(dst_addr,0x000,0x00A0);
// printf("i is %d\n",i);

val=src_addr[i];
printf("val is 0x%x\n",val);
flash_set16(dst_addr,i,val);

ans=flash_get16(dst_addr,i);
//printf("ans is 0x%x\n",ans);
j=0;
while( ans!= val)
{
j++;
if(j>=WAIT_TICKS)
{
flash_set16(dst_addr,0x555,0x0090);
flash_set16(dst_addr,0x000,0x0000);
return -1;
}
ans=flash_get16(dst_addr,i);
}
}
flash_set16(dst_addr,0x555,0x0090);
flash_set16(dst_addr,0x000,0x0000);
return 0;
}

int Read_Sector(int sectorNum,int rd_num,unsigned short *buf)
{
unsigned short *sector_addr;
int i;
int val=0;

if( rd_num <= 0)
{
return -1;
}
printf("flash read start--sectorNum= %d rd_num= %d\n",sectorNum,rd_num);
sector_addr = (u16*)(XPAR_AXI_EMC_0_S_AXI_MEM0_BASEADDR+SECSIZE*sectorNum*2);

printf("sector addr is 0x%x\n",sector_addr);
if( rd_num <= SECSIZE )
{
for(i=0;i<rd_num;i++)
{
printf("val is 0x%x\n",flash_get16(sector_addr,0));
val = flash_get16(sector_addr,0);
*buf=val;
buf++;
sector_addr++;
}
}
else
{
printf("error\n");
}
return 0;
}

int main(int argc, char *argv[])
{

//Erase_Flash(1);

u16 dat[100];
int i;
Read_Sector(0,10,dat);
for(i=0;i<10;i++)
{
printf("0x%x\n",dat[i]);
}
/*
for(i=0;i<100;i++)
{
dat[i]=10+i;
}
Erase_Flash(0);
Write_Sector(0,0,dat,10);
*/
return 0;
}

3、  测试

这里没有驱动的概念，一切都放在用户态执行，编译产生flash应用程序，放到板子上执行程序进行测试即可。注意，写之前要擦除。

下图为写文件的测试，这里写了10个数：



写完以后再读



可以看到，读出来的和写入的值一样，测试通过。

 

4、  补充

关于/dev/mem可以看看下面这段代码，写的很详细，用户态直接访问物理地址，对于ZYNQ中PL部分的操作确实帮助极大。

 

/*
* devmem2.c: Simple program to read/write from/to any location in memory.
*
* Copyright (C) 2000, Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl)
*
*
* This software has been developed for the LART computing board
* (http://www.lart.tudelft.nl/). The development has been sponsored by
* the Mobile MultiMedia Communications (http://www.mmc.tudelft.nl/)
* and Ubiquitous Communications (http://www.ubicom.tudelft.nl/)
* projects.
*
* The author can be reached at:
*
* Jan-Derk Bakker
* Information and Communication Theory Group
* Faculty of Information Technology and Systems
* Delft University of Technology
* P.O. Box 5031
* 2600 GA Delft
* The Netherlands
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#include <ctype.h>
#include <termios.h>
#include <sys/types.h>
#include <sys/mman.h>

#define FATAL do { fprintf(stderr, "Error at line %d, file %s (%d) [%s]\n", \
__LINE__, __FILE__, errno, strerror(errno)); exit(1); } while(0)

#define MAP_SIZE 4096UL
#define MAP_MASK (MAP_SIZE - 1)

int main(int argc, char **argv) {
int fd;
void *map_base, *virt_addr;
unsigned long read_result, writeval;
off_t target;
int access_type = 'w';

if(argc < 2) {
fprintf(stderr, "\nUsage:\t%s { address } [ type [ data ] ]\n"
"\taddress : memory address to act upon\n"
"\ttype : access operation type : [b]yte, [h]alfword, [w]ord\n"
"\tdata : data to be written\n\n",
argv[0]);
exit(1);
}
target = strtoul(argv[1], 0, 0);

if(argc > 2)
access_type = tolower(argv[2][0]);

if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1) FATAL;
printf("/dev/mem opened.\n");
fflush(stdout);

/* Map one page */
map_base = mmap(0, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, target & ~MAP_MASK);
if(map_base == (void *) -1) FATAL;
printf("Memory mapped at address %p.\n", map_base);
fflush(stdout);

virt_addr = map_base + (target & MAP_MASK);
switch(access_type) {
case 'b':
read_result = *((unsigned char *) virt_addr);
break;
case 'h':
read_result = *((unsigned short *) virt_addr);
break;
case 'w':
read_result = *((unsigned long *) virt_addr);
break;
default:
fprintf(stderr, "Illegal data type '%c'.\n", access_type);
exit(2);
}
printf("Value at address 0x%X (%p): 0x%X\n", target, virt_addr, read_result);
fflush(stdout);

if(argc > 3) {
writeval = strtoul(argv[3], 0, 0);
switch(access_type) {
case 'b':
*((unsigned char *) virt_addr) = writeval;
read_result = *((unsigned char *) virt_addr);
break;
case 'h':
*((unsigned short *) virt_addr) = writeval;
read_result = *((unsigned short *) virt_addr);
break;
case 'w':
*((unsigned long *) virt_addr) = writeval;
read_result = *((unsigned long *) virt_addr);
break;
}
printf("Written 0x%X; readback 0x%X\n", writeval, read_result);
fflush(stdout);
}

if(munmap(map_base, MAP_SIZE) == -1) FATAL;
close(fd);
return 0;
}



 

运行截图如下：