Go and reset commands in U-boot

[U-boot: v2013.04]

[Author: Bo Shen <voice.shen@gmail.com>]

1. Source Code

<Common/cmd_boot.c>

Two commands are defined in this file. One is the go command and the other is the reset command.

1.1 go command

If config_cmd_go is defined, a go command is provided. Config_cmd_go is defined in <include/config_cmd_defaults.h>. When the <include/config. h> file is generated using mkconfig, the <include/config_cmdults.h> file is automatically included. Therefore, the config_cmd_go command is defined by default, so the go command is available.

1.2 reset command

During compilation of U-boot, cmd_boot directly contains the reset command.

Reset <Common/cmd_boot.c> --->
Do_reset <ARCH/ARM/lib/reset. c> ---> reset_cpu <ARCH/CPU/arm926ejs/at91/reset. c>

Do_reset calls reset_cpu only after three other tasks are done:

---- Print: Resetting...

---- Delay 50 MS

---- Disable_interrupts <include/common. h> <ARCH/ARM/lib/interrupts. c>

---- If the system does not define config_use_irq, do_interrupts returns 0 directly;

---- If the system defines config_use_irq, do the specific task to disable IRQ/FIQ interrupts.