root access - Enter recovery mode from command line

Does anyone know if there's a way to get an Android phone to reboot into recovery mode, from the Android command line?

Note:

I do NOT have adb access.

I do NOT know the magic power-on sequence to do it from the boot loader. I've tried the common things and nothing works.

I DO have root. (And can enter commands directly on the device using a terminal emulator.)

I know it's possible, somehow, because applications like ROM Manager do it. But how?

Answer

Generally, reboot binary provides a recovery switch. After switching to root, execute this command:

/system/bin/reboot recovery

This may not work if your manufacturer doesn't support it. ROM Manager type apps uses API of Android which you can't access via Terminal Emulator directly.