Question on Git Branches to use [nios2mmu vs unstable-nios2mmu]

[Altera_Forum]

Hi everyone 

 I'm currenlty looking into using Linux on the NIOS for my company. Will be getting a DE4 from Terassic shortly but in the meantime I'm doing all the prepwork to understand as much as possible beforehand. I'm a complete newbie to this whole NIOS/Linux dev so please bear with me...  I'll be using MMU support. I have been trying the build with MMU support using the following git branches: "unstable-nios2mmu" in linux-2.6 "trunk" in uClinux-dist  after setting Vendor=>Altera, Product=>nios2 and then defaulting config settings, building the project has always failed. I have followed the alterawiki instructions as I understand them.  Today after reading the info carefully on this page [alterawiki.com/wiki/Downloading_Linux_Distribution ], specifically the last paragraph, I realised that perphaps the "nios2mmu" branch should be checked out instead of "unstable-nios2mmu" as the shell segment on that page suggests. I then managed to complete a succesful build by again just using default config settings.  The last paragraph on the index nios/linux webpage [alterawiki.com/wiki/Linux_for_the_Nios_II_Processor] however suggests that the "unstable-nios2mmu" is the branch be used (to get a current build). I appreciate that the "unstable-nios2mmu" branch is at kernel rev 2.6.39 and "nios2mmu" branch at 2.6.35.  So, my questions are: 1: Should I be concerned about the "unstable-nios2mmu" branch not compiling 2: Assuming I can get "unstable-nios2mmu" to compile, which branch is the correct/better one to use  Cheers Tones

[Altera_Forum]

root@rl123-c:/home/apr/work/linux/nios2-linux/uClinux-dist# make make -f tools/autotools.mk autotools-cache make: Entering directory `/home/apr/work/linux/nios2-linux/uClinux-dist' make: Nothing to be done for `autotools-cache'. make: Leaving directory `/home/apr/work/linux/nios2-linux/uClinux-dist' chmod +x tools/romfs-inst.sh tools/modules-alias.sh tools/build-udev-perms.sh . linux-2.6.x/.config; if ; then mkdir -p `dirname $CONFIG_INITRAMFS_SOURCE`; touch $CONFIG_INITRAMFS_SOURCE || exit 1; fi rm -f linux-2.6.x/usr/initramfs_data.cpio make ARCH=nios2 CROSS_COMPILE=nios2-linux-gnu- O=/home/apr/work/linux/nios2-linux/uClinux-dist/linux-2.6.x -j1 -C ../linux-2.6 || exit 1 make: Entering directory `/home/apr/work/linux/nios2-linux/linux-2.6' Using /home/apr/work/linux/nios2-linux/linux-2.6 as source for kernel GEN /home/apr/work/linux/nios2-linux/uClinux-dist/linux-2.6.x/Makefile CHK include/linux/version.h CHK include/generated/utsrelease.h CC kernel/bounds.s nios2-linux-gnu-gcc: /include: No such file or directory nios2-linux-gnu-gcc: /include: No such file or directory make: *** Error 1 make: *** Error 2 make: *** Error 2 make: Leaving directory `/home/apr/work/linux/nios2-linux/linux-2.6' make: *** Error 1  

 Hi i am having this error my path only has this   root@rl123-c:/home/apr# echo $PATH /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/home/apr/work/linu x/nios2-linux/toolchain-mmu/x86-linux2/bin:

[Altera_Forum]

I fixed it, seems like it was an error in the Makefile or Kconfig of my board

[Altera_Forum]

Hello everybody, 

 I am also working on Terasic DE4 board, with "unstable-nios2mmu" in linux-2.6 and "trunk" in uClinux-dist.  I follow the steps on Devicetree wiki:  - Compile the dts file from the sopcinfo file - Enter the full path for the devicetree file into the kernel settings, under devicetree support. - Make changes for MTD, LED and JTAG as instructed  However, during the compilation I get the following erros during the the compilation of leds-gpio.o  CC drivers/leds/leds-gpio.o In file included from /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/include/linux/gpio.h:18, from /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/include/linux/of_gpio.h:20, from /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/drivers/leds/leds-gpio.c:18: /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:82: error: redefinition of 'gpio_request' /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:46: error: previous definition of 'gpio_request' was here /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:87: error: redefinition of 'gpio_free' /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:51: error: previous definition of 'gpio_free' was here /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:91: error: static declaration of 'gpio_direction_input' follows non-static declaration /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:54: error: previous declaration of 'gpio_direction_input' was here /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:97: error: static declaration of 'gpio_direction_output' follows non-static declaration /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:55: error: previous declaration of 'gpio_direction_output' was here /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:103: error: static declaration of 'gpio_get_value' follows non-static declaration /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:56: error: previous declaration of 'gpio_get_value' was here /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:108: error: static declaration of 'gpio_set_value' follows non-static declaration /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:57: error: previous declaration of 'gpio_set_value' was here /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:113: error: redefinition of 'gpio_to_irq' /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:60: error: previous definition of 'gpio_to_irq' was here /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:118: error: redefinition of 'irq_to_gpio' /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/arch/nios2/include/asm/gpio.h:65: error: previous definition of 'irq_to_gpio' was here In file included from /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/drivers/leds/leds-gpio.c:18: /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/include/linux/of_gpio.h:74: warning: 'struct gpio_chip' declared inside parameter list /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/include/linux/of_gpio.h:74: warning: its scope is only this definition or declaration, which is probably not what you want /home/user/Desktop/linuxonAltera/nios2-linux/linux-2.6/include/linux/of_gpio.h:75: warning: 'struct gpio_chip' declared inside parameter list make: *** Error 1Please find attached my dts file. I am not sure what is causing the problem. The DE4 system includes 4 TSE modules and DDR Ram.  I would really appreciate any ideas you might have.  Tones, you are the first person I came across who works on compiling the uclinux with mmu for DE4 board. We should combine forces for sure... =)  Kind regards, Turhan

[Altera_Forum]

Hi Turhan 

 Yes, let the forces combine... (3 more and we can start a Captain Planet and the Planeteers gang... haha).  I won't be in front of my PC alot this week, so apologies beforehand for delayed responses.  I don't think that your DTS is the problem here but rather the Kernel Configuration settings. Under the kernel configs=>Device Drivers, what settings do you have enabled under the following headers: - Device Tree and Open Firmware Support - GPIO Support - LED Support  I had a quick scan through your DTS file and doesn't seem like you have GPIO LEDS in your design, so perhaps you could even try and remove all LED functionality from your kernel for now and see if it compiles then.  On a different note, I see that you're using Quartus 10, which is a bit of a shame (from my perspective). I'm really strugling getting the DDR2 controller on the DE4 to work in Quartus 11 with Uniphy. Did you use the Uniphy controller or Altmemphy?  Regards Antonie

[Altera_Forum]

Hi Turhan, 

 the reason why you get errors during compilation is that you probably selected two different drivers which use the same iplementation of gpio. The message "Redefinition" always means that something is already defined.  So my advice is to uncheck one of the settings for the led or gpio support.  Urmel

[Altera_Forum]

I cannot thank you enough Antonie and Urmel. Now I am able to compile the kernel, but I having some problems with downloading it to the DDR2. Will spend some more time on it, and then post again.  

 All the best, Turhan

[Altera_Forum]

Has anyone been able to get the Compact Flash working with the latest unstable release? 

 I am using all the same settings as my working 2.6.35 release, straight out of the wiki, same board, same .sof file, but the new 3.0.x OS, when booting, does not seem to detect nor look for the flash card.  I am also unable to get the serial console to work...quoted below is the JTAG console, which is working. It does seem to load a driver and find the port.   The .dts file segment seems to suggest the Compact Flash has been defined and seen by the sopcinfo -> dts complier.  All else I care about seems to be working...!   cf: ata@0x1000080 { compatible = "ALTR,cf-10.1","ALTR,cf-1.0"; reg = < 0x1000000 0x10 0x1000080 0x40>; interrupt-parent = < &cpu >; interrupts = < 14 15 >; }; //end ata (cf) ALSO: uart0: serial@0x80 { compatible = "ALTR,uart-10.1","ALTR,uart-1.0"; reg = < 0x80 0x20>; interrupt-parent = < &cpu >; interrupts = < 4 >; current-speed = <115200>; //embeddedsw.CMacro.BAUD type NUMBER clock-frequency = <85000000>; //embeddedsw.CMacro.FREQ type NUMBER }; //end serial (uart0) # nios2-terminal nios2-terminal: connected to hardware target using JTAG UART on cable nios2-terminal: "USB-Blaster ", device 1, instance 0 nios2-terminal: (Use the IDE stop button or Ctrl-C to terminate) Linux version 3.0.0-rc7-01121-g1bbc9ab-dirty (Nate@NateFedora) (gcc version 4.1.2)# 57 Fri Jul 22 16:37:01 MDT 2011 bootconsole enabled early_console initialized at 0xe1000010 On node 0 totalpages: 8192 free_area_init_node: node 0, pgdat c657b3d4, node_mem_map c6596800 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 Built 1 zonelists in Zone order, mobility grouping on. Total pages: 8128 Kernel command line: 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: 26728k/5694k RAM (2245k kernel code, 3449k data) NR_IRQS:32 Calibrating delay loop... 40.83 BogoMIPS (lpj=81664) pid_max: default: 32768 minimum: 301 Mount-cache hash table entries: 512 NET: Registered protocol family 16 bio: create slab <bio-0> at 0 SCSI subsystem initialized libata version 3.00 loaded. Switching to clocksource timer NET: Registered protocol family 2 IP route cache hash table entries: 1024 (order: 0, 4096 bytes) TCP established hash table entries: 1024 (order: 1, 8192 bytes) TCP bind hash table entries: 1024 (order: 0, 4096 bytes) TCP: Hash tables configured (established 1024 bind 1024) TCP reno registered UDP hash table entries: 256 (order: 0, 4096 bytes) UDP-Lite hash table entries: 256 (order: 0, 4096 bytes) NET: Registered protocol family 1 RPC: Registered named UNIX socket transport module. RPC: Registered udp transport module. RPC: Registered tcp transport module. RPC: Registered tcp NFSv4.1 backchannel transport module. msgmni has been set to 52 Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254) io scheduler noop registered io scheduler deadline registered io scheduler cfq registered (default) ttyAL0 at MMIO 0x4000060 (irq = 5) is a Altera UART ttyAL1 at MMIO 0x4000080 (irq = 4) is a Altera UART ttyJ0 at MMIO 0x1000010 (irq = 1) is a Altera JTAG UART console enabled, bootconsole disabled console enabled, bootconsole disabled smc91x.c: v1.1, sep 22 2004 by Nicolas Pitre <nico@fluxnic.net> eth0: SMC91C11xFD (rev 2) at e1020300 IRQ 3 eth0: Ethernet addr: 00:07:ed:ff:ab:01 eth0: PHY LAN83C183 (LAN91C111 Internal) mousedev: PS/2 mouse device common for all mice TCP cubic registered NET: Registered protocol family 17 Freeing unused kernel memory: 2832k freed (0xc6233000 - 0xc64f7000) Welcome to ____ _ _ / __| ||_| _ _| | | | _ ____ _ _ _ _ | | | | | | || | _ \| | | |\ \/ / | |_| | |__| || | | | | |_| |/ | ___\____|_||_|_| |_|\____|\_/\_/ | | |_| For further information check: http://www.uclinux.org/ BusyBox v1.18.4 (2011-07-22 15:00:52 MDT) hush - the humble shell Enter 'help' for a list of built-in commands. root:/>

[Altera_Forum]

Turhan, good to hear it's compiling. Regarding memory on the DE4, I had to fall back to Q10.1 since the Uniphy compiled when used in SOPC works there. Q11 has a different top level port map (the global_reset is gone for example) so I'll port my project to Q11 after I figure out what the problem is there. I also have questions/remarks on using RAM but I'm going to start a new thread to keep it more relevant to the thread title. 

 NBB, I'm also working on getting flash working but still having issues with the hardware design. will report back if/when I get to working software stage. About your serial issue, under Device Drivers=>Charracter Devices=>Serial Drivers did you remember to deselect "Altera JTAG UART console support" and only select "Altera UART console support"? In the DTS file, did you modify the bootargs under the chosen node to have your serial device; guessing from your DTS and boot output that must be bootargs="debug console=ttyAL1,115200" if you're using your uart0. For early console information it might not work when you have two Altera UARTS though. temporarily comment out the one you're not using in your DTS, and see if it works then. If it does then I would suggest listing the Altera UART you want to use for early console info first in your DTS. This is just a theory, have a look at setup_early_printk in arch\nios2\kernel\early_printk.c and early_altera_uart_or_juart_console in arch\nios2\kernel\prom.c . It uses the first Altera UART device it finds as the early console. Hope it helps

[Altera_Forum]

Hello guys, 

 It's finally alive. And this is all thanks to you.  First of all, the problem with compilation was caused by the enabled gpio drivers (as Antonie and Urmel suggested). Removing them from the kernel settings solved the problem.  The problem with downloading the kernel to the DDR2 was caused by not following the guidance on (http://www.altera.com/support/kdb/solutions/rd07292010_420.html) carefully. I have 1 GB of DDR2, but changing the column and row address bit widths in the controller, I forced the sopc-generator to address it with 256MBs worth space. This way I kept the memory address in between 0x10000000-0x1FFFFFFF, as suggested. All the other modules need to be addressed between 0x0 and 0x0FFFFFFF. I have changed the DDR2_TOP_BASE to 0x10000000, and DDR2_TOP_SPAN to 268435456 (256Mb) in /nios2-linux/linux-2.6/arch/nios2/include/asm/nios.h, accordingly. In the make configuration, the "Link Address offset for booting" value is 0x02000000.  I had the same error Antonie had with the timer. I fixed it thanks to Pierre.  Now it is time to help Antonie =) If you want to debug the DDR2 against possible faults, you can use the program that comes with DE4 board. (DE4_Control_Panel). For a long time I blamed my own mistakes on the DDR, but it seems it works fine. You can try to write a big file to the DDR, and see if it writes correctly. For the DDR controller, I think you should make a fresh start with (\demonstrations\DE4_230\DE4_DDR2) project in DE4 cd, and make the changes one you are sure things work correctly. I would suggest you to delete the bridge (which connects the cpu to the ddr2 controller). I understand you don't need it for a simple design; the necessary circuit will be implemented on LUTs. (http://www.alteraforum.com/forum/showthread.php?t=29562). I hope this is helpful. Please contact me anytime you want.  Cheers, Turhan

[Altera_Forum]

--- Quote Start ---  It uses the first Altera UART device it finds as the early console. Hope it helps  --- Quote End ---   Good call - I moved uart0 to sit before uart1 in my dts file and all works as before now. uart1 came first by default.  Still no Compact Flash. It appears SCSI drivers are compiling and loading, but there is no detect happening.  I copied the 2C35 design from the wiki for the Compact Flash. It works with 2.6.35 under the nios2mmu code branch. I have a an older Nios II 2C35 demo board, not the DE2.    I have tried 2.6.38 as well, no work there either. It appears the driver is the same revision. I am going to try 2.6.37, but no DTS with this revision.  If anyone has gotten this to work with the unstable-nios2mmu branch 3.0.x code, please post. I would like to stay on the latest code.

[Altera_Forum]

Hi everyone, 

 I want to compile nios2-linux with mmu for Stratix 2. My linux-2.6 branch is nios2 with 3.1.0-rc7. In make menuconfig. In uClinux Distribution Configuration, under the Vendor/Product Selection Category I select Altera as Vendor and nios2 as Altera Products. In Kernel/Library/Defaults Selection i chhose Customize Kernel Settings.   In Kernel Configuration, in Platform Options, i set the Memory base address and memory size. I also Select Compile and link device tree into kernel image and set the path to .dts file. In Device Drivers, i select Memory Technology Device(MTD) support and in it under Mapping drivers for chip access and in it I select Flash device physical memory based on OF description. In Character Devices-> Serial drivers i select Altera UART support and Altera UART console support. This is based on bootrags from .dts file. For Led Support I deslect it. The selection all based on http://www.alterawiki.com/wiki/devicetree. Every other selection is default.   I save it. But make it cause errors.   make -f tools/autotools.mk autotools-cache make: Entering directory `/home/nuar/Programs/nios2-linux/uClinux-dist' make: Nothing to be done for `autotools-cache'. make: Leaving directory `/home/nuar/Programs/nios2-linux/uClinux-dist' chmod +x tools/romfs-inst.sh tools/modules-alias.sh tools/build-udev-perms.sh . linux-2.6.x/.config; if ; then mkdir -p `dirname $CONFIG_INITRAMFS_SOURCE`; touch $CONFIG_INITRAMFS_SOURCE || exit 1; fi rm -f linux-2.6.x/usr/initramfs_data.cpio make ARCH=nios2 CROSS_COMPILE=nios2-linux-gnu- O=/home/nuar/Programs/nios2-linux/uClinux-dist/linux-2.6.x -j8 -C ../linux-2.6 || exit 1 make: Entering directory `/home/nuar/Programs/nios2-linux/linux-2.6' GEN /home/nuar/Programs/nios2-linux/uClinux-dist/linux-2.6.x/Makefile CHK include/linux/version.h Using /home/nuar/Programs/nios2-linux/linux-2.6 as source for kernel /home/nuar/Programs/nios2-linux/linux-2.6 is not clean, please run 'make mrproper' in the '/home/nuar/Programs/nios2-linux/linux-2.6' directory. make: *** Error 1 make: *** Error 2 make: Leaving directory `/home/nuar/Programs/nios2-linux/linux-2.6' make: *** Error 1   How to successfully compile nios2-linux with mmu? Having alot of trouble. Any help would be appreciated. Thank you.  Moganesh

[Altera_Forum]

Hello Moganesh, 

 I had the same problem, and I solved it by typing make mrproper.  However, you will loose the configurations you have made, and possible some files that you have added in the folders. I would say make a backup of all the files you have changed, run make mrproper, and then restore the files.  I hope this will be helpful. It solved the problem in my case.  All the best, Turhan

[Altera_Forum]

Hi Turhan, 

 After struggling for hours and with help I managed to make it. I cd to linux-2.6 and make mrproper. Cd to uclinux-dist and make. I downloaded to FPGA. But the following error occur at nios2-terminal:  nuar@nuar-desktop:~/Programs/nios2-linux/uClinux-dist/images$ nios2-download -g zImage.initramfs.gz  rpm: Command not found. Using cable "USB-Blaster [USB 5-1.1]", device 1, instance 0x00 Pausing target processor: OK Initializing CPU cache (if present) OK Downloaded 3942KB in 34.5s (114.2KB/s) Verified OK  Starting processor at address 0xC3500000 nuar@nuar-desktop:~/Programs/nios2-linux/uClinux-dist/images$ nios2-terminalnios2-terminal: connected to hardware target using JTAG UART on cable nios2-terminal: "USB-Blaster [USB 5-1.1]", device 1, instance 0 nios2-terminal: (Use the IDE stop button or Ctrl-C to terminate)  Linux version 3.1.0-rc7-01765-g9b1c815 (nuar@nuar-desktop) (gcc version 4.1.2)# 18 Thu Sep 29 13:50:51 MYT 2011 bootconsole [early0] enabled early_console initialized at 0xe4001020 On node 0 totalpages: 8192 free_area_init_node: node 0, pgdat c2550f8c, node_mem_map c25667a0  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: init=/bin/init 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: 26920k/5522k RAM (2189k kernel code, 3332k data) NR_IRQS:32 Calibrating delay loop... 77.82 BogoMIPS (lpj=155648) pid_max: default: 32768 minimum: 301 Mount-cache hash table entries: 512 NET: Registered protocol family 16 bio: create slab <bio-0> at 0 Switching to clocksource timer NET: Registered protocol family 2 IP route cache hash table entries: 1024 (order: 0, 4096 bytes) TCP established hash table entries: 1024 (order: 1, 8192 bytes) TCP bind hash table entries: 1024 (order: 0, 4096 bytes) TCP: Hash tables configured (established 1024 bind 1024) TCP reno registered UDP hash table entries: 256 (order: 0, 4096 bytes) UDP-Lite hash table entries: 256 (order: 0, 4096 bytes) NET: Registered protocol family 1 RPC: Registered named UNIX socket transport module. RPC: Registered udp transport module. RPC: Registered tcp transport module. RPC: Registered tcp NFSv4.1 backchannel transport module. JFFS2 version 2.2. (NAND) © 2001-2006 Red Hat, Inc. msgmni has been set to 52 Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254) io scheduler noop registered io scheduler deadline registered io scheduler cfq registered (default) ttyJ0 at MMIO 0x4001020 (irq = 1) is a Altera JTAG UART console [ttyJ0] enabled, bootconsole disabled console [ttyJ0] enabled, bootconsole disabled mousedev: PS/2 mouse device common for all mice TCP cubic registered NET: Registered protocol family 17 Freeing unused kernel memory: 2740k freed (0xc2225000 - 0xc24d2000) Oops: Exception in kernel mode, sig: 4  r1: c2000cc0 r2: 00000000 r3: 00004ff8 r4: 80000000 r5: 00004b98 r6: 00000468 r7: ffffe000 r8: 00000002 r9: c381c8e8 r10: c255bfe0 r11: 00000000 r12: 00000001 r13: c3058de0 r14: c255cbb4 r15: 00000001 ra: c0001004 fp: 00000006 sp: c3c19d5c gp: 00000000 ea: c20b5d24 estatus: 00000001 Kernel panic - not syncing: Attempted to kill init!  Moganesh

[Altera_Forum]

This is about the timer you have used in your system. Please check the earlier posts in this thread. There is a detailed explanation for how to create the clock for the system. Cheers.

[Altera_Forum]

Hi, 

 The timer is fully featured and the period is in ms. But still having the same error.  Moganesh

[Altera_Forum]

I had the same error because of the timer (kernel panic). I don't have any idea if it is caused by something else. I am sorry.  

 Only think that pops to my mind is: "Oops: Exception in kernel mode, sig: 4" Do you follow the menuconfig settings as posted on the wiki? The problem occurs after freeing unused memory. You can perhaps try to understand what that means.