AmigaOne - U-Boot - Initialisation
When the computer is started, the basic x86 emulator integrated into U-boot will perform a number of hardware checks which can only be seen by connecting a null-modem cable to the serial port and capturing the output on another computer or serial terminal as shown below:
The exact content that is captured will depend on your machine and the components connected to it, but the same checks will be done albeit with different results. If you have any hardware issues that cause the machine to fail before reaching the display stage, this is a useful place to look.
It then executes the ROM of your graphics card, at which point the display will be switched on and the first information will appear. The remaining hardware is then checked and initialised. U-Boot will display what kind of hardware you have:
U-Boot Initialisation Display
Pressing any key will terminate the countdown sequence. However, if you press the Space bar, it will go straight to the U-Boot Menuboot Delay panel, otherwise the U-Boot Console will be displayed.
U-Boot Console Display
The U-boot console lets you execute directly a lot of commands as detailed in the U-Boot Commands section. It's a bit like using an Amiga or Linux shell but a very basic one with no short-cuts. You can display information about your hardware, display and set environment variables, boot an operating system etc.
One very important piece of information you can see from this screen is the U-Boot version information at the top of the
screen. This may show different information depending on the version of the firmware:
release in the U-Boot ROM, such as:
Occasionally you may see a spate of error messages for the CDROM or DVD drives as shown below:
This is nothing to get alarmed about - it simply means that you have left a non-bootable CD (probably a music CD) in the drive and U-Boot couldn't read it.
U-Boot Booting Options
If "boota" is specified it then reads the bootcmd environment variable and executes the value specified. The default value is "menu; run menuboot_cmd" which instructs U-Boot to display the U-Boot Menuboot Delay Panel which in turn loads the First-Level Booter and then to run the value specified by the menuboot_cmd environment variable as discussed below.
U-Boot Menuboot Delay Panel
Pressing any key will terminate the countdown sequence. If you press the Enter Key it will invoke the U-Boot Boot Select screen, but if you press any other key it will invoke the U-Boot Preferences Menu screen. If no keys are pressed the First-Level booter will run.
As you can see it's role is to scan the hard drives to locate the Second Level Booter, and load it.
Disclaimer: Amiga Auckland have prepared the above information for the use of its members based on our experiences and as such is subject to revision at any time. Amiga Auckland cannot guarantee any of the information and cannot be held accountable for any issues that may result from using it.