手把手教你在友善之臂tiny4412上用uboot启动Linux内核
要想用uboot启动内核,我推荐一种方法,用dnw下载内核到开发板上,然后用uboot命令启动:
首先我在网上随便下了一个dnw工具,经过移植修改后,代码如下:
/*
YYX--->for tiny4412 dnw
version:20170423
v1
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <malloc.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdint.h>
const char* dev = "/dev/secbulk0";
#define BLOCK_SIZE (1*1024*1024)
struct download_buffer {
uint32_t load_addr; /* load address */
uint32_t size; /* data size */
uint8_t data[0];
/* uint16_t checksum; */
};
static int _download_buffer(struct download_buffer *buf)
{
int fd_dev = open(dev, O_WRONLY);
if( -1 == fd_dev) {
printf("Can not open %s: %s\n", dev, strerror(errno));
return -1;
}
printf("Writing data...\n");
size_t remain_size = buf->size;
size_t block_size = BLOCK_SIZE;
size_t writed = 0;
while(remain_size>0) {
size_t to_write = remain_size > block_size ? block_size : remain_size;
if( to_write != write(fd_dev, (unsigned char*)buf + writed, to_write)) {
perror("write failed");
close(fd_dev);
return -1;
}
remain_size -= to_write;
writed += to_write;
printf("\r%02zu%%\t0x%08zX bytes (%zu K)",
(size_t)((uint64_t)writed*100/(buf->size)),
writed,
writed/1024);
fflush(stdout);
}
printf("\n");
close(fd_dev);
return 0;
}
static inline void cal_and_set_checksum(struct download_buffer *buf)
{
uint16_t sum = 0;
int i;
for(i = 0; i < buf->size; i++) {
sum += buf->data[i];
}
*((uint16_t*)(&((uint8_t*)buf)[buf->size - 2])) = sum;
}
static struct download_buffer* alloc_buffer(size_t data_size)
{
struct download_buffer *buffer = NULL;
size_t total_size = data_size + sizeof(struct download_buffer) + 2;
buffer = (typeof(buffer))malloc(total_size);
if(NULL == buffer)
return NULL;
buffer->size = total_size;
return buffer;
}
static void free_buffer(struct download_buffer *buf)
{
free(buf);
}
static struct download_buffer *load_file(const char *path, unsigned long load_addr)
{
struct stat file_stat;
struct download_buffer *buffer = NULL;
unsigned long total_size;
int fd;
fd = open(path, O_RDONLY);
if(-1 == fd) {
printf("Can not open file %s: %s\n", path, strerror(errno));
return NULL;
}
if( -1 == fstat(fd, &file_stat) ) {
perror("Get file size filed!\n");
goto error;
}
buffer = alloc_buffer(file_stat.st_size);
if(NULL == buffer) {
perror("malloc failed!\n");
goto error;
}
if( file_stat.st_size != read(fd, buffer->data, file_stat.st_size)) {
perror("Read file failed!\n");
goto error;
}
buffer->load_addr = load_addr;
cal_and_set_checksum(buffer);
return buffer;
error:
if(fd != -1)
close(fd);
if( NULL != buffer )
free(buffer);
return NULL;
}
static int download_file(const char *path, unsigned long load_addr)
{
struct download_buffer *buffer;
struct timeval __start, __end;
long __time_val = 0;
float speed = 0.0;
buffer = load_file(path, load_addr);
gettimeofday(&__start,NULL);
if (buffer != NULL) {
if (_download_buffer(buffer) == 0) {
gettimeofday(&__end,NULL);
__time_val = (long)(__end.tv_usec - __start.tv_usec)/1000 + \
(long)(__end.tv_sec - __start.tv_sec) * 1000;
speed = (float)buffer->size/__time_val/(1024*1024) * 1000;
printf("speed: %fM/S\n",speed);
free_buffer(buffer);
} else {
free_buffer(buffer);
return -1;
}
} else
return -1;
}
int main(int argc, char* argv[])
{
unsigned load_addr = 0x57e00000;
char* path = NULL;
int c;
while ((c = getopt (argc, argv, "a:h")) != EOF)
switch (c) {
case 'a':
load_addr = strtol(optarg, NULL, 16);
continue;
case '?':
case 'h':
default:
usage:
printf("Usage: dwn [-a load_addr] <filename>\n");
printf("Default load address: 0x57e00000\n");
return 1;
}
if (optind < argc)
path = argv[optind];
else
goto usage;
printf("load address: 0x%08X\n", load_addr);
if (download_file(path, load_addr) != 0) {
return -1;
}
return 0;
}
然后我们还要写一个Makefile,用来编译dnw这个工具:
如下:
dnw : dnw.c
gcc -g -o [email protected] $^
clean :
rm -rf dnw *.o
install : dnw
cp $^ /usr/bin
然后make , 编译成功
在当前目录下可以看到生成了dnw这个二进制文件。
接下来,我们还需要一个驱动secbulk,于是再去网上下载:
源码如下:
在源码中,我们看到:{ USB_DEVICE(0x04e8, 0x1234) }, /* EZTIN4412 */
这一行是我自己添加的,该驱动要知道4412开发板USB的设备ID还有厂商ID,这个信息可以通过lsusb来获得,如下:
查看方法如下:
(1)先在minicom中敲一下dnw,会弹出这个界面等待PC文件传输过来。
(2)然后回到PC端,敲lsusb命令,如图:
从上图,我们看到Samsung Electiornics Co. , Ltd , 所以得知开发板的ID是04e8:1234
所以以下代码就要添加这么一个ID:{ USB_DEVICE(0x04e8, 0x1234) }, /* EZTIN4412 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/fs.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#define SECBULK_MAJOR 102
#define SECBULK_MINOR 0
#define DRIVER_NAME "secbulk"
#define BULKOUT_BUFFER_SIZE (4*1024)
struct secbulk_dev
{
struct usb_device *udev;
struct mutex io_mutex;
char* bulkout_buffer;
__u8 bulk_out_endpointAddr;
};
static struct usb_class_driver secbulk_class;
static struct usb_device_id secbulk_table[]= {
{ USB_DEVICE(0x5345, 0x1234) }, /* FS2410 */
{ USB_DEVICE(0x04e8, 0x1234) }, /* TINY4412 */
{ }
};
static struct usb_driver secbulk_driver;
static void secbulk_disconnect(struct usb_interface *interface)
{
struct secbulk_dev *dev = NULL;
printk(KERN_INFO "secbulk:secbulk disconnected!\n");
dev = usb_get_intfdata(interface);
if( NULL != dev )
kfree(dev);
usb_deregister_dev(interface, &secbulk_class);
return;
}
static ssize_t secbulk_read(struct file *file, char __user *buf, size_t len,
loff_t *loff)
{
return -EPERM;
}
static ssize_t secbulk_write(struct file *file, const char __user *buf,
size_t len, loff_t *loff)
{
size_t to_write;
struct secbulk_dev *dev = file->private_data;
int ret;
int actual_length;
size_t total_writed;
total_writed = 0;
while(len > 0) {
to_write = min(len, BULKOUT_BUFFER_SIZE);
if(copy_from_user(dev->bulkout_buffer, buf+total_writed,
to_write)) {
printk(KERN_ERR "secbulk:copy_from_user failed!\n");
return -EFAULT;
}
ret = usb_bulk_msg(dev->udev,
usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
dev->bulkout_buffer,
to_write,
&actual_length,
3*HZ);
if(ret || actual_length!=to_write) {
printk(KERN_ERR "secbulk:usb_bulk_msg failed!\n");
return -EFAULT;
}
len -= to_write;
total_writed += to_write;
}
return total_writed;
}
static int secbulk_open(struct inode *node, struct file *file)
{
struct usb_interface *interface;
struct secbulk_dev *dev;
interface = usb_find_interface(&secbulk_driver, iminor(node));
if(!interface)
return -ENODEV;
dev = usb_get_intfdata(interface);
dev->bulkout_buffer = kzalloc(BULKOUT_BUFFER_SIZE, GFP_KERNEL);
if(!(dev->bulkout_buffer))
return -ENOMEM;
if(!mutex_trylock(&dev->io_mutex))
return -EBUSY;
file->private_data = dev;
return 0;
}
static int secbulk_release(struct inode *node, struct file *file)
{
struct secbulk_dev *dev;
dev = (struct secbulk_dev*)(file->private_data);
kfree(dev->bulkout_buffer);
mutex_unlock(&dev->io_mutex);
return 0;
}
static struct file_operations secbulk_fops = {
.owner = THIS_MODULE,
.read = secbulk_read,
.write = secbulk_write,
.open = secbulk_open,
.release= secbulk_release,
};
static struct usb_class_driver secbulk_class = {
.name = "secbulk%d",
.fops = &secbulk_fops,
.minor_base= 100,
};
static int secbulk_probe(struct usb_interface *interface, const struct usb_device_id *id)
{
int ret;
struct secbulk_dev *dev;
struct usb_host_interface *iface_desc;
struct usb_endpoint_descriptor *endpoint;
int i;
printk(KERN_INFO "secbulk:secbulk probing...\n");
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if(!dev) {
ret = -ENOMEM;
goto error;
}
iface_desc = interface->cur_altsetting;
for(i=0; i < iface_desc->desc.bNumEndpoints; i++) {
endpoint = &(iface_desc->endpoint[i].desc);
if(!dev->bulk_out_endpointAddr
&& usb_endpoint_is_bulk_out(endpoint)) {
printk(KERN_INFO "secbulk:bulk out endpoint found!\n");
dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
break;
}
}
if(!(dev->bulk_out_endpointAddr)) {
ret = -EBUSY;
goto error;
}
ret = usb_register_dev(interface, &secbulk_class);
if(ret) {
printk(KERN_ERR "secbulk: usb_register_dev failed!\n");
return ret;
}
dev->udev = usb_get_dev(interface_to_usbdev(interface));
usb_set_intfdata(interface, dev);
mutex_init(&dev->io_mutex);
return 0;
error:
if(!dev)
kfree(dev);
return ret;
}
static struct usb_driver secbulk_driver= {
.name= "secbulk",
.probe= secbulk_probe,
.disconnect= secbulk_disconnect,
.id_table= secbulk_table,
};
static int __init secbulk_init(void)
{
int result;
printk(KERN_INFO "secbulk:secbulk loaded\n");
result = usb_register(&secbulk_driver);
if(result) {
printk(KERN_ERR "secbulk:usb_register failed: %d", result);
return result;
}
return 0;
}
static void __exit secbulk_exit(void)
{
usb_deregister(&secbulk_driver);
printk(KERN_INFO "secbulk:secbulk unloaded\n");
}
module_init(secbulk_init);
module_exit(secbulk_exit);
MODULE_LICENSE("GPL");
接下来,我们来写一个Makefile:
#obj-m := secbulk.o
#secbulk-m := secbulk.o
obj-m := secbulk.o
KDIR := /lib/modules/`uname -r`/build
PWD := $(shell pwd)
default:
$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules
clean:
$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) clean
rm -rf *.order *.symvers
然后在当前目录下make
编译成功如下:
编译成功以后,需要执行
chmod 777 secbulk.ko
sudo insmod secbulk.ko将内核插入系统。
接下来,还要安装一个库,方法:
sudo apt-get install libusb-dev
万事具备,只欠东风,现在可以启动minicom来尝试下载内核了
方法如下:
(1)在minicom端执行dnw 0x40008000,如图:
(2)切换到另外一个终端
然后执行dnw arch/arm/boot/zImage
切换到minicom端看到下载成功如下图:
接下来,在uboot中敲击bootm 0x40008000,注意不要打tab按键,否则你回看到以下未识别的信息:
我们重新来一次:
成功启动内核!!!!