Currently we can choose two versions of linux kernel to boot with nios2, which are uclinux distribution
and linux-socfpga with buildroot.
Preparing materials
uclinux version set up steps:
1. Set up toolchain
1.1 First choice, codesourcery (according to toolchain setup step of nios2 linux manual on rocketboards)
https://sourcery.mentor.com/GNUToolchain/release2499
Choose version of IA32 GNU/Linux Installer and install it.
By /bin/sh <Codesourcery>.bin
Then
□ export PATH=/<your path>/CodeSourcery/Sourcery_CodeBench_Lite_for_Nios_II_GNU_Linux/bin/:$PATH
□ export ARCH=nios2
□ export CROSS_COMPILE=nios2-linux-gnu1.2 Second choice, old toolchain-mmu.
Download
git clone git://sopc.et.ntust.edu.tw/git/toolchain-mmu.git
Then set your path to:
export PATH=$PATH:/<your path>/toolchain-mmu/x86-linux2/bin/
Very important notification:
Only choose one toolchain and make sure only one path of above in your “echo $PATH”, or there will be
a lot of strange errors when compiling linux kernel. Don’t mess up your path.
2. Download and set uclinux-dist
git clone git://gitorious.org/linux-nios2/uclinux-dist.git
Set git branch to trunk by: git checkout –f trunk
3. Download linux-2.6 kernel
git clone git://sopc.et.ntust.edu.tw/git/linux-2.6.git
Set git branch to nios2: git checkout –f master
4. Sopc2dts tool and generate your device tree.
4.1 Download
git clone git://sopc.et.ntust.edu.tw/git/tools.git
4.2 Set up your tool, execute following command:
□ cd tools/sopc2dts
□ make
□ java –jar sopc2dts.jar - - gui
4.3 Generate Device Tree
□ In Input->choose file, select your .sopcinfo file.
□ In Boardinfo menu, hit Apply. Then change debug console=ttyAL0.11520 to debug
console=ttyJ0.11520 to enable jtag-uart console
□ In output menu, save it as .dts file.
socfpga version set up steps:
reference: http://www.rocketboards.org/foswiki/Documentation/NiosIILinuxUserManual
1. set up toolchain exactly as uclinux-dist set-up toolchain step.
2. Set up buildroot for root files system
2.1 Get your file:
□ git clone http://git.buildroot.net/git/buildroot.git
□ cd buildroot
□ git branch -a (to check for latest remote version)
□ X don’t use this step git checkout -t -b 2013.08.x origin/2013.08.x (use the latest version)
Only branch of master has nios2 architecture.
Download Nios II config file for Buildroot:
http://www.rocketboards.org/pub/Documentation/NiosIILinuxUserManual/nios2_defconfig.
2.2 Generate rootfs for nios2.
Add this file to <buildroot_top_directory>/configs.
Go to Buildroot top directory and configure Buildroot for Nios II:
□ make nios2_defconfig
To customize Buildroot configuration:
□ make menuconfig
To build:

You need to be connected to the network before make as the script must download and install packages.
□ make
Output file name : rootfs.jffs2, rootfs.cpio, rootfs.tar
Output directory : <Buildroot_top_directory>/output/images
2.3 Download linux kernel
git clone http://git.rocketboards.org/linux-socfpga.git
cd linux-socfpga
□ git branch -a (to check for latest remote version)
□ git checkout -t -b <socfpga-3.11> origin/<socfpga-3.11> (use the latest version)
Go to Linux top directory and configure Linux kernel for Nios II.
□ make 3c120_defconfig
To build:
□ make vmImage
The kernel we could use is: <your_kernel_path>/vmlinux.
New Kernel building procedure
1. Go to linux-socfpga top directory, type command
□ make menuconfig
2. Include your root files system in your RAM:
General setup -> Initial RAM filesystem and RAM disk (initramfs/initrd) support (press Y as enable, press
N as disenable).
Next, enter the path "<your_path>/buildroot/output/images/rootfs.cpio" under General setup ->
Initramfs source file(s)
3. Set Kernel features ->Timer frequency to 1000HZ.
4. Set Platform options -> Memory base address to your main memory’s address. Here our main
memory is ddr3 sdram. Its base address is 0x04000000.
5. Enable Platform options -> Compile and link device tree into kernel image and type your device tree in
the path.
6. Don’t touch Advance setup, treat it as default.
7. Make vmImage
8. bash /opt/altera/13.0sp1/nios2eds/nios2_command_shell.sh
9. nios2-download –g vmlinux && nios2-terminal
So far, we could only move this far. Booting stop at msgmni has been set to 114.
We don’t know what causes this problem. However we have tested cases as below:
□ Toolchain-mmu with uclinux
□ Toolchain-mmu with socfpga
□ Codesourcery toolchain with uclinux
□ Codesourcery toolchain with socfpga
Different buildroot branch
What’s more, we have tried case in which we change buildroot branch to 2013.08.x (latest version),
then we build the kernel with different files systems. The error message is different as:
No root files systems results
Conclusion:
The result of make old uclinux-dist is the same, stucking at ‘msgmni has been set to 115’. According to
the cases I have tested, I don’t think it is the problem of toolchain. And I believe, though it is suggested
that we should use lastest buildroot branch, we should use the branch of ‘master’ to choose nios2 as the
architecture.
The tutorial for make uclinux kernel can be:
http://www.youtube.com/watch?v=RxlyezOf0Rs
Error and solution
Most of my errors occurs when I build the old uclinux.
Error1:
glob.c error: “ARG_MAX” undeclared
&&
Glob.c error:”ARG_MAX” undeclared
.
.
.
&
CC
loginutils/passwd.o
loginutils/passwd.c: In function ‘passwd_main’:
loginutils/passwd.c:104:16: error: storage size of ‘rlimit_fsize’ isn’t known
loginutils/passwd.c:188:2: warning: implicit declaration of function
‘setrlimit‘ [-Wimplicit-function-declaration]
loginutils/passwd.c:188:12: error: ‘RLIMIT_FSIZE’ undeclared (first use in this
function)
loginutils/passwd.c:188:12: note: each undeclared identifier is reported only
once for each function it appears in
loginutils/passwd.c:104:16: warning: unused variable ‘rlimit_fsize’ [-Wunusedvariable]
make[1]: *** [loginutils/passwd.o] Error
make: *** [loginutils] Error 2
Solution:
First in your uclinux-dist top directory
□ find ./ -name libbb.h,
Then add #include <sys/resource.h> to libbb.h
Error2:
stdm++.cxx:1:18: error: stdm++: No such file or directory
stdm++.cxx:4: error: 'MATT' has not been declared
stdm++.cxx:4: error: expected constructor, destructor, or type conversion before
'(' token
stdm++.cxx:21: error: 'MATT' has not been declared
stdm++.cxx:21: error: expected constructor, destructor, or type conversion before
'::' token
stdm++.cxx:34: error: 'MATT' has not been declared
stdm++.cxx:34: error: 'int operator<<(char*)' must have an argument of class or
enumerated type
stdm++.cxx:34: error: 'int operator<<(char*)' must take exactly two arguments
stdm++.cxx: In function 'int operator<<(char*)':
stdm++.cxx:36: error: invalid use of 'this' in non-member function
stdm++.cxx:36: error: 'fprintf' was not declared in this scope
stdm++.cxx: At global scope:
stdm++.cxx:41: error: 'MATT' has not been declared
stdm++.cxx:41: error: expected constructor, destructor, or type conversion before
'MATT'Solution:
Solution:
Generally, if you set your toolchain PATH correctly, it will compile the kernel after all. If you get stuck at
this error, you may have some problems with PATH. The most secure solution is to set Codesourcery as
your toolchain PATH.
Error3:
/opt/altera/13.0sp1/nios2eds/bin/nios2-gdb-server-wrapped: error while loading shared libraries:
libjtag_client.so: cannot open shared object file: No such file or directory
Solution:
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/opt/altera/13.0sp1/quartus/linux/
Error4:
I found these errors when I boot the kernel.
□ Timer’s IRQ number should not be 0. Though it is suggested by the old uclinux version, this will cause
booting stuck at ‘Calibrating delay loop...’ We would better set Timer’s IRQ to 11.
□ nios2 cpu’s exception vector offset should be set to 0x00000020! Otherwise it cause unhandled
exception vector as below: