问Yocto修补程序从外树模块导出具有外部符号的Linux内核树内模块

EN

static unsigned char lan9730_mac_address_buffer[6];
EXPORT_SYMBOL(lan9730_mac_address_buffer);

diff -Naur kernel-source/drivers/net/usb/smsc95xx.c kernel-source.new/drivers/net/usb/smsc95xx.c
--- kernel-source/drivers/net/usb/smsc95xx.c    2020-08-04 22:34:02.767157368 +0000
+++ kernel-source.new/drivers/net/usb/smsc95xx.c        2020-08-04 23:34:27.528435689 +0000
@@ -917,6 +917,27 @@
 {
        const u8 *mac_addr;
 
+       printk("=== smsc95xx_init_mac_address ===\n");
+       printk("%x:%x:%x:%x:%x:%x\n",
+           lan9730_mac_address_buffer[0],
+           lan9730_mac_address_buffer[1],
+           lan9730_mac_address_buffer[2],
+           lan9730_mac_address_buffer[3],
+           lan9730_mac_address_buffer[4],
+           lan9730_mac_address_buffer[5]);
+       printk("=== mac_addr is set ===\n");
+       if (lan9730_mac_address_buffer[0] != 0xff &&
+           lan9730_mac_address_buffer[1] != 0xff &&
+           lan9730_mac_address_buffer[2] != 0xff &&
+           lan9730_mac_address_buffer[3] != 0xff &&
+           lan9730_mac_address_buffer[4] != 0xff &&
+           lan9730_mac_address_buffer[5] != 0xff) {
+           printk("=== SUCCESS ===\n");
+           memcpy(dev->net->dev_addr, lan9730_mac_address_buffer, ETH_ALEN);
+           return;
+       }
+       printk("=== FAILURE ===\n");
+
        /* maybe the boot loader passed the MAC address in devicetree */
        mac_addr = of_get_mac_address(dev->udev->dev.of_node);
        if (!IS_ERR(mac_addr)) {
diff -Naur kernel-source/drivers/net/usb/smsc95xx.h kernel-source.new/drivers/net/usb/smsc95xx.h
--- kernel-source/drivers/net/usb/smsc95xx.h    2020-08-04 22:32:30.824951447 +0000
+++ kernel-source.new/drivers/net/usb/smsc95xx.h        2020-08-04 23:33:50.486778978 +0000
@@ -361,4 +361,6 @@
 #define INT_ENP_TDFO_                  ((u32)BIT(12))  /* TX FIFO Overrun */
 #define INT_ENP_RXDF_                  ((u32)BIT(11))  /* RX Dropped Frame */
 
+extern unsigned char lan9730_mac_address_buffer[6];
+
 #endif /* _SMSC95XX_H */

|   GEN     ./Makefile
|   Using /home/me/Desktop/poky/build-microchip/tmp/work-shared/sama5d27-som1-ek-sd/kernel-source as source for kernel
|   CALL    /home/me/Desktop/poky/build-microchip/tmp/work-shared/sama5d27-som1-ek-sd/kernel-source/scripts/checksyscalls.sh
|   Building modules, stage 2.
|   MODPOST 279 modules
| ERROR: "lan9730_mac_address_buffer" [drivers/net/usb/smsc95xx.ko] undefined!

msg "Inserting lan9730-mac-address.ko..."
insmod /mnt/lib/modules/4.19.78-linux4sam-6.2/extra/lan9730-mac-address.ko
ls -rlt /proc/lan9730-mac-address
head -c 6 /dev/mtdblock0 > /proc/lan9730-mac-address

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <linux/slab.h>

const int BUFFER_SIZE = 6;

int write_length, read_length;
unsigned char lan9730_mac_address_buffer[6];
EXPORT_SYMBOL(lan9730_mac_address_buffer);

int read_proc(struct file *filp, char *buf, size_t count, loff_t *offp)
{
    // Read bytes (returning the byte count) until all bytes are read.
    // Then return count=0 to signal the end of the operation.

    if (count > read_length)
        count = read_length;

    read_length = read_length - count;
    copy_to_user(buf, lan9730_mac_address_buffer, count);

    if (count == 0)
        read_length = write_length;

    return count;
}

int write_proc(struct file *filp, const char *buf, size_t count, loff_t *offp)
{
    if (count > BUFFER_SIZE)
        count = BUFFER_SIZE;

    copy_from_user(lan9730_mac_address_buffer, buf, count);
    write_length = count;
    read_length = count;
    return count;
}

struct file_operations proc_fops = {
    read: read_proc,
    write: write_proc
};

void create_new_proc_entry(void)  //use of void for no arguments is compulsory now
{
    proc_create("lan9730-mac-address", 0, NULL, &proc_fops);
}

int proc_init (void) {
    create_new_proc_entry();
    memset(lan9730_mac_address_buffer, 0x00, sizeof(lan9730_mac_address_buffer));
    return 0;
}

void proc_cleanup(void) {
    remove_proc_entry("lan9730-mac-address", NULL);
}

MODULE_LICENSE("GPL");
module_init(proc_init);
module_exit(proc_cleanup);