Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Linux, U-Boot, and Root File Systems

I'm working with a Nios II design with an MMU, on a Nios II Development Kit, Cyclone II Edition board (EP2C35). I'm trying to figure out how to get to a system that boots with some sort of root...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

There are a few reasons I would like to use U-Boot.

It allows me to switch between kernel builds easily.

It allows me to boot with an nfs filesystem, which is convenient for application development.

I have an I2C-based RTC added to my board, and the Linux RTC driver expects the clock chip to be initialized by pre-Linux code. I'm looking to U-Boot to provide that pre-Linux initialization code. (Getting the I2C working in U-Boot is my next project.)

--

I downloaded the zImage.initramfs.gz file to the board, with nios2-download. This runs, and gets me to a command prompt, just like linux.initramfs.gz does.

zImage.initramfs.gz does not seem to be an image suitable for U-Boot. I tried downloading it directly to the board via U-Boot tftp, then running it using the U-Boot command "go".

I also tried packing it up with mkimage, then downloading the result to the board with tftp, and booting from it with the U-Boot command "bootm".

I eventually want to burn the filesystem into flash, and boot from U-Boot without a network connection.

-Pinta