作者genty ()
看板LinuxDev
標題Re: [核心] embedded linux 開機訊息
時間Tue Jun 21 00:12:19 2011
※ 引述《powertodream (The Beginning)》之銘言：
: 想請問一下
: 在實驗板上面的 linux 開起來
: 可以讓他的訊息經由 serial port 傳給 host 端的終端機軟體
: 理解沒錯的話,
: linux是透過tty 再傳出去的嗎?
: 那是怎麼設定讓linux這樣動作?
: 那外部連到實驗板上, linux 的運作原理是?
: 這一段的流程不太懂, 可以請板友指點一下, 或者有沒有相關文件可以閱讀
: 謝謝
Please refer to Linux/Documentation/arm/Booting
...
Essentially, the boot loader should provide (as a minimum) the
following:
1. Setup and initialise the RAM.
2. Initialise one serial port.
The boot loader should initialise and enable one serial port on the
target. This allows the kernel serial driver to automatically detect
which serial port it should use for the kernel console (generally
used for debugging purposes, or communication with the target.)
3. Detect the machine type.
4. Setup the kernel tagged list.
5. Call the kernel image.
...
Or you can find something like this in /etc/inittab
ttyS0::respawn:-/bin/sh
also, use "ps" command to observe the processes running in your
embedded system, you would find the process which serves
for this login shell.
PS.In an embedded system, the serial device of a SOC usually is
registered as a platform device.
see linux/Documentation/driver-model/platform.txt
also see linux/arch/{ARCH}/mach-xxx/board-xxx.c
... if there is any....
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 123.193.82.238