Problem Booting uClinux on DE2

Can anyone help me? I'm trying to get uClinux running on a DE2 board.

Ultimately, after making an image to download, the system does not fully boot. The symptoms are similar to a thread I found on the forum: "uClinux 20100621 - connecting NIOS HW with linux" but playing with the load offset and trimming down the kernel doesn't produce any different result.

Thanks in advance.

D.W. Lynn

Here are the details:

I'm using a Centos6 system.

For the most part I have followed the current instructions on the wiki at "Linux for the Nios II Processor"

I did step 1, adding a "yum install libuuid-devel" as I found (later) that libuuid.a was missing on my system. I also had to make a few minor changes to makefiles since my make is 3.82.

I found step 2 a bit confusing since it indicates that one should now install i"nios2-linux-20100621.tar". Is this necessary? This tarball contains what seems to be a subset of what was already installed in step 1.

I skipped this step.

I did go to nios2-linux/linux-2.6 and checked out the unstable-nios2mmu branch

I then did ./checkout in nios2-linux.

I then successfully went through step3 except I don't have a 3C120 system to test with.

At this point I setup an MMU based system for my DE2 board. Following the hints in step 4, I added 1KB of dual-port tightly-coupled on-chip memory and setup the caches and assigned the fast TLB miss exception vector to address 0 in the added on-chip memory. The system also has 8MB of SDRAM at address 0x10000000, a JTAG UART, a system timer, LED and switch ports and a University program clock module (which provides a PLL for SDRAM clock timing).

Did I miss something? I wasn't able to find any reference to a minimal set of hardware requirements.

I then followed the step 8 devicetree instructions to build and include a dts file for my system. Some kernel config options were described differently, but I believe that I found and set them all.

After configuring my .sof, I downloaded the zImage. It downloaded to 0xc1000000 through 0xc13f0000 and verified as indicated below:

Using cable "USB-Blaster [1-1.1]", device 1, instance 0x00

Pausing target processor: OK

Initializing CPU cache (if present)

OK

Downloaded 4009KB in 21.5s (186.4KB/s)

Verified OK

Starting processor at address 0xC1000000

but did not boot, as indicated below:

[lynnd@Doug-new ~]$ nios2-terminal

nios2-terminal: connected to hardware target using JTAG UART on cable

nios2-terminal: "USB-Blaster [1-1.1]", device 1, instance 0

nios2-terminal: (Use the IDE stop button or Ctrl-C to terminate)

nios2-terminal: exiting due to ^C on host

You can see that it did not boot.

If I download the vmlinux image, I get the following:

[lynnd@Doug-new ~]$ nios2-download -g nios2-linux/uClinux-dist/images/vmlinux

Using cable "USB-Blaster [1-1.1]", device 1, instance 0x00

Pausing target processor: OK

Initializing CPU cache (if present)

OK

Downloaded 2795KB in 14.9s (187.5KB/s)

Verified OK

Starting processor at address 0xC0000000

[lynnd@Doug-new ~]$ nios2-terminal

nios2-terminal: connected to hardware target using JTAG UART on cable

nios2-terminal: "USB-Blaster [1-1.1]", device 1, instance 0

nios2-terminal: (Use the IDE stop button or Ctrl-C to terminate)

Linux version 3.1.0-rc4-01162-g45c9dd8 (lynnd@Doug-new.faculty.cset.oit.edu) (gcc version 4.1.2)# 8 Mon Nov 5 16:25:58 PST 2012

bootconsole [early0] enabled

early_console initialized at 0xe1411050

On node 0 totalpages: 8192

free_area_init_node: node 0, pgdat c02bb060, node_mem_map c02d0a20

DMA zone: 64 pages used for memmap

DMA zone: 0 pages reserved

DMA zone: 8128 pages, LIFO batch:0

pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768

pcpu-alloc: [0] 0

Built 1 zonelists in Zone order, mobility grouping on. Total pages: 8128

Kernel command line: debug console=ttyJ0,115200

PID hash table entries: 128 (order: -3, 512 bytes)

Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)

Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)

Memory available: 29568k/2874k RAM (2191k kernel code, 682k data)

NR_IRQS:32

Unable to handle kernel NULL pointer dereference at virtual address 00000000

ea = c0227c7c, ra = c0227c4c, cause = 15

Kernel panic - not syncing: Oops