作者genty ()
看板LinuxDev
标题Re: [核心] embedded linux 开机讯息
时间Tue Jun 21 00:12:19 2011
※ 引述《powertodream (The Beginning)》之铭言:
: 想请问一下
: 在实验板上面的 linux 开起来
: 可以让他的讯息经由 serial port 传给 host 端的终端机软体
: 理解没错的话,
: linux是透过tty 再传出去的吗?
: 那是怎麽设定让linux这样动作?
: 那外部连到实验板上, linux 的运作原理是?
: 这一段的流程不太懂, 可以请板友指点一下, 或者有没有相关文件可以阅读
: 谢谢
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....
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