必须将 CONFIG_SERIAL_8250 配置为 yes ， 否则启动时候 console=ttyS0 没有效果，但是 console=tty0 不受影响。

也是由于 SERIAL_8250_CONSOLE 对于 CONFIG_SERIAL_8250=y 有依赖

config SERIAL_8250_CONSOLE
	bool "Console on 8250/16550 and compatible serial port"
	depends on SERIAL_8250=y
	select SERIAL_CORE_CONSOLE
	select SERIAL_EARLYCON

如果把 SERIAL_8250=m ，那么将会有如下的 module 消失了。

kernel/drivers/tty/serial/serial_base.ko
kernel/drivers/tty/serial/8250/8250.ko
kernel/drivers/tty/serial/8250/8250_base.ko
kernel/drivers/tty/serial/8250/8250_exar.ko
kernel/drivers/tty/serial/8250/8250_lpss.ko
kernel/drivers/tty/serial/8250/8250_mid.ko
kernel/drivers/tty/serial/8250/8250_pci.ko
kernel/drivers/tty/serial/8250/8250_pericom.ko

kernel/drivers/misc/eeprom/eeprom_93cx6.ko
kernel/lib/fonts/font.ko
kernel/lib/math/rational.ko

总体符合预期，就是两个路径。

drivers/input/serio/i8042.c 这个是做什么的?

这个是做什么的?

drivers/usb/serial/bus.c

那么 serial over lan 是什么?

在 qemu 的 stdio 中 dmesg ，最后可以触发这个错误

irq4 ，如何分配的

[  419.999920] link port-storage as upper device of eth2
[  448.267378] serial8250: too much work for irq4
[  448.403917] serial8250: too much work for irq4
[  448.541998] serial8250: too much work for irq4
[  448.696771] serial8250: too much work for irq4
[  448.860427] serial8250: too much work for irq4
[  449.020484] serial8250: too much work for irq4
[  449.155814] serial8250: too much work for irq4
[  449.295326] serial8250: too much work for irq4
[  449.428446] serial8250: too much work for irq4
[  449.582178] serial8250: too much work for irq4
[  455.103230] serial8250_interrupt: 1 callbacks suppressed
[  455.103235] serial8250: too much work for irq4
[  455.259182] serial8250: too much work for irq4
[  455.398221] serial8250: too much work for irq4
[  455.538640] serial8250: too much work for irq4
[  455.693459] serial8250: too much work for irq4
[  455.846877] serial8250: too much work for irq4
[  456.000410] serial8250: too much work for irq4
[  456.153424] serial8250: too much work for irq4
[  456.306691] serial8250: too much work for irq4
[  456.457983] serial8250: too much work for irq4

想不到注册中断是后面进行的:

• entry_SYSCALL_64
  • do_syscall_64
    • do_syscall_x64
      • __x64_sys_openat
        • __se_sys_openat
          • __do_sys_openat
            • do_sys_open
              • do_sys_openat2
                • do_filp_open
                  • path_openat
                    • do_open
                      • vfs_open
                        • do_dentry_open
                          • chrdev_open
                            • tty_open
                              • uart_open
                                • tty_port_open
                                  • uart_port_activate
                                    • uart_startup
                                      • uart_startup
                                        • uart_port_startup
                                          • serial8250_do_startup
                                            • univ8250_setup_irq
                                              • serial_link_irq_chain
                                                • request_irq
                                                  • request_threaded_irq
                                                    • __setup_irq
                                                      • irq_setup_forced_threading

本站所有文章转发 CSDN 将按侵权追究法律责任，其它情况随意。