This config file can be found under /boot/grub/grub.conf. I'm wondering what is quiet mean in this config file.
kernel /vmlinuz-2.6.32-71.29.1.el6.i686 ro root=UUID=977d4c1d-6127-409f-b53a-694c17e13d90
rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM
LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us
crashkernel=auto LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc
KEYTABLE=us quiet biosdevname=eth0 usbcore.autosuspend=-1
I search around the internet but I couldn't find any good resources explaining about this parameter.
If you are referring to a kernel boot parameter of quiet, then that is to disable most log messages.
Linux kernel boot parameters.
Related
I am working on microzed 7010 board, I have manualy compiled kernel, u-boot, fsbl, and .bit (vivado). Board is booting well with all setup (without using petalinux). But i have noticed that kernel is not Uncompressing kernel... with zImage nor uImage. whereas i can see bootlogs with that of petalinux's images.
INPUT :
1 . zImage env is
zImage=tftpboot 0x3000000 zImage && tftpboot 0x2A00000 system.dtb && bootz 0x3000000 - 0x2A00000
2 . Boot log is =>
Zynq> run zImage
[2017-10-25 15:57:11
ethernet#e000b000 Waiting for PHY auto negotiation to complete......... TIMEOUT !
[2017-10-25 15:57:15
Zynq> run zImage
[2017-10-25 15:57:22
Using ethernet#e000b000 device
TFTP from server 172.16.9.187; our IP address is 172.16.9.25
Filename 'zImage'.
Load address: 0x3000000
Loading:#####################################################################################################################################################################################################################################
3.9 MiB/s
done
Bytes transferred = 3913840 (3bb870 hex)
Using ethernet#e000b000 device
TFTP from server 172.16.9.187; our IP address is 172.16.9.25
Filename 'system.dtb'.
Load address: 0x2a00000
Loading: #
3.3 MiB/s
done
Bytes transferred = 13644 (354c hex)
Kernel image # 0x3000000 [ 0x000000 - 0x3bb870 ]
## Flattened Device Tree blob at 02a00000
Booting using the fdt blob at 0x2a00000
Loading Device Tree to 1fff9000, end 1ffff54b ... OK
Starting kernel ...
Booting Linux on physical CPU 0x0
Linux version 4.6.0-xilinx-00003-g2762bc9 (pritam#pritam) (gcc version 5.2.1 20151005 (Linaro GCC 5.2-2015.11-2) ) #3 SMP PREEMPT Wed Oct 25 10:28:387
[2017-10-25 15:57:24
CPU: ARMv7 Processor [413fc090] revision 0 (ARMv7), cr=18c5387d
3 . In u-boot I have given bootz support
4 . uImage is formed by
mkimage -A arm -O linux -T kernel -C none -a 0x10000000 -e 0x10000000 -n "Linux kernel" -d arch/arm/boot/zImage uImage
What causing it not to uncompress kernel ? Is u-boot compressing the kernel and booting ?
Any help will be appreciated.
Thanks and regards,
Pritam
Board is booting well with all setup (without using petalinux). But i have noticed that kernel is not Uncompressing kernel... with zImage nor uImage.
Some kernels can perform this step silently. The fact that you load a zImage (or a zImage in a uImage), and then see the Linux kernel version line means that the kernel has been uncompressed successfully and is executing
What causing it not to uncompress kernel ?
Your presumption that the kernel is not being uncompressed is simply wrong.
The zImage or uImage files that you are using are compressed kernel images. Since the kernel is actually executing (as evidenced by the boot log that you posted), the kernel must have silently uncompressed and proceeded to boot.
If the kernel did not uncompress (as you assert), then the kernel could not boot successfully (as you reported).
Is u-boot compressing the kernel and booting ?
No, U-Boot is not involved in uncompressing a zImage file.
A zImage is a self-extracting compressed Image file.
Depending on how the kernel was configured, the uncompression of the zImage file can be silent or verbose.
I have cloned the source codes from petalinux downloads. The boot logs, I got from images built by petalinux, shows Uncompressing kernel .... message. " Starting kernel ... Uncompressing Linux... done, booting the kernel. Booting Linux on physical CPU 0x0 Linux version 4.6.0-xilinx (pritam#pritam) (gcc version 5.2.1" So i am expecting it to show "uncompressing kernel " message
Using the same source code is only one requisite for building a duplicate kernel.
You also need to build with the same configuration.
The silent or verbose uncompression is selected by kernel configuration.
From arch/arm/Kconfig.debug:
menu "Kernel hacking"
...
config DEBUG_LL
bool "Kernel low-level debugging functions (read help!)"
depends on DEBUG_KERNEL
help
Say Y here to include definitions of printascii, printch, printhex
in the kernel. This is helpful if you are debugging code that
executes before the console is initialized.
Note that selecting this option will limit the kernel to a single
UART definition, as specified below. Attempting to boot the kernel
image on a different platform *will not work*, so this option should
not be enabled for kernels that are intended to be portable.
...
prompt "Kernel low-level debugging port"
...
config DEBUG_ZYNQ_UART0
bool "Kernel low-level debugging on Xilinx Zynq using UART0"
depends on ARCH_ZYNQ
help
Say Y here if you want the debug print routines to direct
their output to UART0 on the Zynq platform.
config DEBUG_ZYNQ_UART1
bool "Kernel low-level debugging on Xilinx Zynq using UART1"
depends on ARCH_ZYNQ
help
Say Y here if you want the debug print routines to direct
their output to UART1 on the Zynq platform.
If you expect a verbose uncompression, then you need to select CONFIG_DEBUG_KERNEL, CONFIG_DEBUG_LL, and an appropriate serial port.
ADDENDUM (response to comment)
Which one is better way to compress the kernel. zImage or gzipping arch/arm/Image ... are they same ... ???
What metric are you going to use to measure "better"?
In the end, the result is the same: a compressed kernel Image.
How many of these image files to you have to save?
How crucial is saving space and load times (if any) versus self-extraction?
In mkimage if I specified -C "gzip", I noticed that at time of loading image in ram, u-boot uncompresses the gzipped image ... !!!
As I already commented, that is a mislabeling of a zImage file, and therefore wrong. The zImage is self-extracting, and should be labeled as "uncompressed" so that U-Boot does not try to perform uncompression.
Interestingly I cannot duplicate your claim at the shell prompt. A zImage renamed to zImage.gz cannot be gunzip'd:
gzip: zImage.gz: not in gzip format.
More importantly, I cannot replicate the results that you claim you got.
=> bootm 20080000 - 22000000
## Booting kernel from Legacy Image at 20080000 ...
Image Name: Linux kernel
Image Type: ARM Linux Kernel Image (gzip compressed)
Data Size: 5774280 Bytes = 5.5 MiB
Load Address: 20008000
Entry Point: 20008000
Verifying Checksum ... OK
## Flattened Device Tree blob at 22000000
Booting using the fdt blob at 0x22000000
Uncompressing Kernel Image ... Error: Bad gzipped data
gzip compressed: uncompress error -1
Must RESET board to recover
resetting ...
Does u-boot contains external decompresser ... ???
If you had bothered to read the link I had provided previously, the answer would be obvious.
U-Boot can be configured to have gzip, bzip2, lzma, and lzo compression algorithms.
However the Linux kernel supports compressing the Image file using gzip, lzo, lzma, xz, and lz4 compression algorithms, that is, a wider selection of size versus time tradeoffs.
Which one better compression method whether in u-boot or kernel (zImage).
Again, what metric are you going to use to measure "better"?
Of course Wolfgang Denk has his opinion.
Plz explain me with actual example (If any h/w requirement) ... !!!
Example of what?
I've already answered your question, and explained how you can configure your kernel to get the expected message.
The issue was with specifying the compression type "-C" as none.
mkimage -A arm -O linux -T kernel **-C none** -a 0x10000000 -e 0x10000000 -n "Linux kernel" -d arch/arm/boot/zImage uImage
So I tried with vmlinux. and converted it to gzip
mkimage -A arm -O linux -T kernel **-C gzip** -a 0x10008000 -e 0x10008000 -n 'Test' -d vmlinux.bin.gz uImage.
So I have noticed size of both images .
first one is of vmlinux and another of zImage
So please correct me if i am misunderstood .
I compiled a linux kernel for my Toshiba AC100 and want to boot it via uboot.
Problem: After displaying the message "Starting Kernel" nothing happens.
The flag CONFIG_DEBUG_LL was set but there is still no output after this message.
I have another precompiled kernel (but too old to use) which comes with its own dtb file and this one boots (same bootargs as the non-booting kernel).
Observation: If I change the dbt file for this kernel it shows the same behavior as the non-booting kernel, just displaying the "Starting kernel" line.
So I guess my problem is related to the dbt file I use for my kernel.
Are there any methods to check if the dbt file is right for my board?
What else could I do to get some information what the problem is?
The entry in the boot.scr:
setenv bootargs 'root=/dev/mmcblk0p7 rootfstype=ext4 earlyprintk=vga console=tty0 mem=448M#0'
setenv bootmenu_4 "Boot Arch Linux =ext2load mmc 0:7 0x1000000 /boot/zImage; ext2load mmc 0:7 0x2000000 /boot/tegra20-paz00.dtb; bootz 0x1000000 - 0x2000000"
And here's the output form u-boot:
2255488 bytes read in 116 ms (18.5 MiB/s)
14153 bytes read in 82 ms (168 KiB/s)
Kernel image # 0x1000000 [ 0x000000 - 0x226a80 ]
## Flattened Device Tree blob at 02000000
Booting using the fdt blob at 0x2000000
Loading Device Tree to 0fff9000, end 0ffff748 ... OK
Starting kernel ...
I tried also to extract the config from the working kernel and built a new kernel with this config, but this one does not work, too (does not matter which dtb file I use).
EDIT:
Finally I solved it by changing the kernel config from
CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA
to
CONFIG_TEGRA_DEBUG_UARTA
After this, the kernel boots fine.
I followed tutorial http://www.howtoforge.com/virtualization-with-xen-on-centos-6.2-x86_64-paravirtualization-and-hardware-virtualization
To install xen on Centos 6.3 everything is going perfect but, after editing /boot/grub/menu.lst
Quote:
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/mapper/vg_xen-LogVol01
# initrd /initrd-[generic-]version.img
#boot=/dev/sdb
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.32.57-2.el6xen.x86_64)
root (hd0,0)
kernel /xen.gz dom0_mem=1024M cpufreq=xen dom0_max_vcpus=1 dom0_vcpus_pin
kernel /vmlinuz-2.6.32.57-2.el6xen.x86_64 ro root=/dev/mapper/vg_xen-LogVol01 rd_NO_LUKS LANG=en_US.UTF-8 rd_LVM_LV=vg_xen/LogVol01 rd_LVM_LV=vg_xen/lv_swap rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=128M KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32.57-2.el6xen.x86_64.img
title CentOS (2.6.32-279.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-279.el6.x86_64 ro root=/dev/mapper/vg_xen-LogVol01 rd_NO_LUKS LANG=en_US.UTF-8 rd_LVM_LV=vg_xen/LogVol01 rd_LVM_LV=vg_xen/lv_swap rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=128M KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32-279.el6.x86_64.img
when i reboot it is booted with xen kernel but when i run command
xm info or xm list
showing error
" Error: Unable to connect to xend: No such file or diectory. Is xend running "
when i run command
xend start
showing error
" xc: error: Could not obtain handle on privileged command interface (2 = No such file or directory): Internal error
xend/image.py: Error connecting to hypervisor "
ls /proc/xen
" ls: cannot access /proc/xen: No such file or directory "
added entry in /etc/fstab
Quote:
none /proc/xen xenfs default 0 0
after reboot gives error no such file or directory,
lsmod | grep -i xen output: Nothing...
modprob xen-evtchn
FATAL: Error inserting xen_evtchn (/lib/modules/2.6.32.57-2.el6xen.x86_64/kernel/drivers/xen/xen-evtchn.ko): No such device
modprob xen-gntdev
FATAL: Error inserting xen_gntdev (/lib/modules/2.6.32.57-2.el6xen.x86_64/kernel/drivers/xen/xen-gntdev.ko): No such device
I have enabled hardware virtulization in bios still problem not solved.
I tried another tutorial https://www.crc.id.au/xen-on-rhel6-scientific-linux-6-centos-6-howto/
it seems like nothing is working for me...
Guys... please share your thoughts about this problem...
Thank you.
i ran into this too in booting a Xen dom0 kernel.
i might have spotted one small omission in your grub.conf compared to the instructions.
in the grub config section at this line: "replace the first word initrd with module."
for example, here's my working Xen Dom0 grub.conf.
good luck!
default=0
timeout=2
title CentOS 6.3 Xen dom0
root (hd0,0)
kernel /boot/xen.gz loglvl=all guest_loglvl=all
module /boot/vmlinuz-dom0-kernel ro root=/dev/sda1 nomodeset console=ttyS0,115200 iommu=off earlyprintk=xen initcall_debug debug loglevel=10
module /boot/initrd-dom0-kernel.img
title CentOS 6.3 (No Xen)
root (hd0,0)
kernel /boot/vmlinuz-dom0-kernel ro root=/dev/sda1
initrd /boot/initrd-dom0-kernel.img
title Stock CentOS 6.3
root (hd0,0)
kernel /boot/vmlinuz-centos6.3 ro root=/dev/sda1
initrd /boot/initrd-centos6.3.img
This does the trick!
Check your boot entries in grub. I just upgraded my Centos 6.3 with the kernel-xen-3.5.3-1 to 3.7.1-3 and the new boot entry for this kernel gets wrong because between updates I installed a standard kernel for testing other things.
Fixing the correct boot options for xen brings back my virtualization!
title CentOS (3.7.1-3.el6xen.x86_64)
root (hd0,0)
kernel /xen.gz dom0_mem=1024M cpufreq=xen dom0_max_vcpus=4 dom0_vcpus_pin
module /vmlinuz-3.7.1-3.el6xen.x86_64 ro root=UUID=<longUUID> KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 crashkernel=auto rhgb quiet
module /initramfs-3.7.1-3.el6xen.x86_64.img
I had the same issue:
Could not obtain handle on privileged command interface (2 = No such file or directory): Internal error
This was solved by adding the below line in /etc/fstab
none /proc/xen xenfs defaults 0 0
See this post in the Xen Project mailing list for more details.
I'm trying to add a switch to send linux kernel log to the serial console on XenServer6.
The kernel command options can be edited on the EXTLinux config file ( /boot/extlinux.conf ).
Here is an excerpt:
serial 1 115200
default xe
prompt 1
timeout 50
label xe
# XenServer
kernel mboot.c32
append /boot/xen.gz mem=1024G dom0_max_vcpus=4 dom0_mem=752M lowmem_emergency_pool=1M crashkernel=64M#32M console= vga=mode-0x0311 --- /boot/vmlinuz-2.6-xen root=LABEL=root-tfnnfzfp ro xencons=hvc com2=115200,8n1 console=com2 console=hvc0 console=tty0 quiet vga=785 splash --- /boot/initrd-2.6-xen.img
label xe-serial
# XenServer (Serial)
kernel mboot.c32
append /boot/xen.gz com1=115200,8n1 console=com1,vga mem=1024G dom0_max_vcpus=4 dom0_mem=752M lowmem_emergency_pool=1M crashkernel=64M#32M --- /boot/vmlinuz-2.6-xen root=LABEL=root-tfnnfzfp ro console=tty0 xencons=hvc console=hvc0 --- /boot/initrd-2.6-xen.img
What is the meaning of the triple dashes ( --- )on the command line?
Is it loading 3 boot files?
TL;DR Yes, it is. ExtLinux must load both Xen and the Linux kernel. It uses mboot.c32 to do this. --- separates the Xen image path and its command line from the Linux image path and its command line.
This is just the way that ExtLinux (indeed, all boot loaders in the SysLinux family) implement multiboot, which is necessary to load Xen.
Most simple boot configurations will load just a kernel. There's a way that the boot loader writes the command line where you would expect it. In Syslinux style:
label Simple
kernel linux.c32
append <linux kernel filename> <linux command line>
Or in Grub:
title Simple Boot
root (hd0,0)
kernel <linux kernel filename> <linux command line>
More complex boot configurations might load boot Xen and the kernel. These use a system called "multiboot", which loads both and gives them each their own command line. That allows you to pass Xen its commands and Linux its commands. You can even pass in another stage to load something else, like an initial ramdisk. In SysLinux style:
label Complex
kernel mboot.32
append <xen kernel filename> <xen command line> --- <linux kernel filename> <kernel command line> --- <initrd filename>
Or in Grub:
label Complex Boot
kernel <xen kernel filename> <xen command line>
module <linux kernel filename> <linux command line>
module <initrd filename>
If you were using grub, it actually specifies these in their own stanzas. Grub acts as sort of a super-bootloader in that it can have tons of little modules loaded into it for functionality such as multiboot (or different filesystems, etc). In that case, Grub does most of it magically without you knowing.
Syslinux and family divide labor differently. Rather than having one giant boot loader that must handle all situations, they have two layers that have many different pieces. On the top, they have the core boot loader that knows the system its booting (i.e. syslinux knows BIOS booting with files on FAT filesystem, pxelinux knows loading things over then network, isolinux knows loading files from a CD-ROM, etc.). Extlinux is just the one that knows how to boot off of an Ext2, Ext3, Ext4, or BTRFS filesystem.
Other common functionality is implemented as "comboot" modules, which can plug into any of the boot loaders. For example:
multiboot (mboot.c32)
directly loading a Linux kernel (linux.c32)
menu support (menu.c32)
Lua Interpreter (lua.c32)
hardware detection tool (hdt.c32)
alternate boot based on CPU flags (ifcpu.c32)
In the case of multiboot, they load the mboot.c32 module, which implements multiboot. Unlike Grub and family (which know about the multiple command lines), syslinux must include all of the modules and their commandlines in a single commandline. Since -- is often used as an argument separator in other programs, they chose to use --- to delimit the modules.
In this case, Xen requires multiboot, which is requiring that syntax to separate the command lines for the Xen Hypervisor Kernel and the Linux Kernel that runs as its initial privileged guest.
i'm new to embedded linux field. i am trying to emulate arm develpmnt board using Qemu and boot linux on to it. i compiled the kernel and got the uImage.but when i test this image on qemu it shows--
qemu: fatal: Trying to execute code outside RAM or ROM at 0x50008000
R00=00000000 R01=00000183 R02=00000100 R03=00000000
R04=00000000 R05=00000000 R06=00000000 R07=00000000
R08=00000000 R09=00000000 R10=00000000 R11=00000000
R12=00000000 R13=00000000 R14=00000000 R15=50008000
PSR=400001d3 -Z-- A svc32
Aborted.
i used this command for testing
qemu-system-arm -M versatilepb -m 128M -kernel /root/ls6410/kernel/s3c-linux-2.6.28.6-Real6410/arch/arm/boot/uImage.
can anyone suggest an method to fix this?
thanks,