journalctl -k
journalctl -b
dmesg
+dmest -wH
efibootmgr
```
+# LINUX KERNEL PANIC KDUMP
+
+```shell
+
+# should be enabled
+# /boot/config
+
+CONFIG_RELOCATABLE=y
+CONFIG_KEXEC=y
+CONFIG_CRASH_DUMP=y
+CONFIG_DEBUG_INFO=y
+
+
+sudo apt update
+
+sudo apt install kdump-tools crash kexec-tools makedumpfile linux-image-$(uname -r)-dbg
+
+# yes
+
+# reboot
+
+sudo grep USE_KDUMP /etc/default/kdump-tools
+
+grep LOAD_KEXEC /etc/default/kexec
+
+```
+
# GCC G++ CLANG COMPILE
```shell
//spin_unlock(&q_lock);
+ printk("value: %02x%02x%02x%02x...%02x%02x%02x%02x\n",
+ i_value[0],
+ i_value[1],
+ i_value[2],
+ i_value[3],
+ i_value[MAX_PKTLEN-4],
+ i_value[MAX_PKTLEN-3],
+ i_value[MAX_PKTLEN-2],
+ i_value[MAX_PKTLEN-1]
+ );
+
napi_schedule(&priv->napi);
printk(KERN_INFO "napi interrupt end\n");
return IRQ_HANDLED;
} else {
if(gpio_ctl_i != 0 && gpio_ctl_o != 0){
+
geth_interrupt(0, geth_devs, NULL);
}else {
printk("value: %02x%02x%02x%02x...%02x%02x%02x%02x\n",