E.5.1 Loading Milo from the Windows NT ARC firmware

      Most, if not all, Alpha AXP based systems include the Windows NT ARC firmware and this is the prefered method of booting Milo and thus Linux. Once the Windows NT firmware is running and you have the correct Milo image for your system, this method is completely generic.

The Windows NT ARC firmware is an environment in which programs can run and make callbacks into the firmware to perform actions. The Windows NT OSLoader is a program that does exactly this. Linload.exe is a much simpler program which does just enough to load and execute Milo. It loads the appropriate image file into memory at 0x00000000 and then makes a swap-PAL PALcall to it. Milo, like Linux, uses a different PALcode to Windows NT which is why the swap has to happen. Milo relocates itself to 0x200000 and continues on through the PALcode reset entry point as before.

Before you add a Linux boot option, you will need to copy linload.exe and the appropriate Milo that you wish to load to someplace that the Windows NT ARC firmware can read from. In the following example, I assume that you are booting from a DOS format floppy disk:

1. At the boot menu, select Supplementary menu...
2. At the Supplementary menu, select Set up the system...
3. At the Setup menu, select Manage boot selection menu...
4. In the Boot selections menu, choose Add a boot selection
5. Choose Floppy Disk 0
6. Enter linload.exe as the osloader directory and name
7. Say ``yes'' to the operating system being on the same partition as the osloader
8. Enter `` '' as the operating system root directory
9. I usually enter ``Linux'' as the name for this boot selection
10. Say ``No'' you do not want to initialise the debugger at boot time
11. You should now be back in the Boot selections menu, choose the Change a boot selection option and pick the selection you just created as the one to edit
12. Use down arrow to get OSLOADFILENAME up and then type in the name of the Milo image that you wish to use, for example noname.arc
13. Press to get back to the Boot Selections menu
14. Choose Setup Menu (or hit again) and choose Supplementary menu, and save changes option
15. will get you back to the Boot menu and you can attempt to boot Milo. If you do not want Linux as the first boot option, then you can alter the order of the boot options in the Boot selections menu.

At the end of all this, you should have a boot selection that looks something like:

LOADIDENTIFIER=Linux
SYSTEMPARTITION=multi(0)disk(0)fdisk(0)
OSLOADER=multi(0)disk(0)fdisk(0)\linload.exe
OSLOADPARTITION=multi(0)disk(0)fdisk(0)
OSLOADFILENAME=\noname.arc
OSLOADOPTIONS=

You can now boot Milo (and then Linux). You can load linload.exe and Milo directly from a file system that Windows NT understands such as NTFS or DOS on a hard disk.     The contents OSLOADOPTIONS are passed to Milo which interprets it as a command. So, in order to boot Linux directly from Windows NT without pausing in Milo, you could pass the following in OSLOADOPTIONS:

boot sda2:vmlinux.gz root=/dev/sda2

See section E.6 Milo's User Interface for more information on the commands available.

Another (rather sneaky) way of loading of loading Milo via the WNT ARC firmware is to put Milo onto an MS-DOS floppy and call it fwupdate.exe and then choose the ``Upgrade Firmware'' option.