RE: [Ilugc] kernel build option - ramdisk
Hi, The initrd image usually contains some drivers that are not built-in the kernel, and required to access hardware when the kernel boots. But, one can also use the initrd image as a filesystem image (root filesystem directories from busybox, for example) that can be booted with the kernel to give the end user a shell prompt to work with -- like the use of a LiveCD/DVD running entirely on RAM that has both kernel and initrd filesystem image. Thanks for clarification. Still I have some couple of question. 1) So initrd is first file which executes first in the boot process (if present) . Am I correct? 2) There are so many variances in the kernel image file (vmlinuz, bzImage, zImage, etc). What is the difference? How do we build each? I may be stupid, But just want to clarify initrd is the ramdisk correct? Thanks. Suresh ___ ILUGC Mailing List: http://www.ae.iitm.ac.in/mailman/listinfo/ilugc
Re: [Ilugc] kernel build option - ramdisk
Hi, --- On Mon, Feb 8, 2010 at 2:26 PM, Suresh Kumar Subramanian sureshkuma...@carc.co.in wrote: | So initrd is first file which executes first in the boot process (if present) . Am I correct? \-- 'File that executes'? The initrd is loaded onto RAM, and its starting location is passed to the kernel, so it will treat is as any other block device, and use its contents. --- | 2) There are so many variances in the kernel image file (vmlinuz, bzImage, zImage, etc). | What is the difference? \-- I would assume they use different compression algorithms. --- | How do we build each? \-- The Makefile that builds the kernel has specific targets to build these images. For example (x86): http://lxr.linux.no/#linux+v2.6.32/arch/x86/Makefile So, just doing 'make bzImage' (default) would build the bzImage. --- | I may be stupid, \-- You are not. You are just ignorant, and feel free to ask questions. It also helps to do some homework before you ask such questions using a search engine (Google, for example), as you will find answers to such questions online. --- | But just want to clarify initrd is the ramdisk correct? \-- Yes. SK -- Shakthi Kannan http://www.shakthimaan.com ___ ILUGC Mailing List: http://www.ae.iitm.ac.in/mailman/listinfo/ilugc
Re: [Ilugc] kernel build option - ramdisk
Hi, --- On Fri, Feb 5, 2010 at 12:37 PM, Suresh Kumar Subramanian sureshkuma...@carc.co.in wrote: | 2)) building the RootFS disk controller for that disk in to the kernel. \-- Can you re-phrase this statement? Disk controller is hardware. An initrd is also a root filesystem image. --- | I assume that, ramdisk image is the separate image for only filesystem (initrd) and | the second options is no initrd image file, kernel file(vmlinux) includes the filesystem also. | Is that correct? \-- The term you are looking for is called a 'bootpImage' that has a disk image and the kernel in a single image. Let us first be clear on some terminology. The initrd image usually contains some drivers that are not built-in the kernel, and required to access hardware when the kernel boots. But, one can also use the initrd image as a filesystem image (root filesystem directories from busybox, for example) that can be booted with the kernel to give the end user a shell prompt to work with -- like the use of a LiveCD/DVD running entirely on RAM that has both kernel and initrd filesystem image. SK -- Shakthi Kannan http://www.shakthimaan.com ___ ILUGC Mailing List: http://www.ae.iitm.ac.in/mailman/listinfo/ilugc
Re: [Ilugc] kernel build option - ramdisk
On 4:07pm, Suresh Kumar Subramanian wrote: Can you please share your experience if you come across this (ramdisk or inbuilt). Use ramdisk, if you have too many uncentinities about HW. For example, the default kernel in distro has no idea about the final HW. Use in-built, if you know the exact info about HW. Otherwise, in-built kernel size will be too large. Bye :) -- Bharathi S ___ ILUGC Mailing List: http://www.ae.iitm.ac.in/mailman/listinfo/ilugc
