Mainline kernel First of all: don’t use that github link (it’s just a mirror). The actual repositories are located at kernel.org. You probably want to use Linus Torvalds’ tree, which is torvalds/linux.git. It’s called mainline kernel, which means this tree is the one where actual development of next kernel version is happening. Although it has … Read more
From those three factors that you have listed only the first one is actually correct. As for the rest — not really. It is possible for a user space code to perform DMA operations — no problem with that. There are many hardware appliance companies who employ this technique in their products. It is also … Read more
I’ve figured out the answer to my question, so I thought I’d add it here. Below is the patch that will add a new scheduler to the 2.6.34 vanilla kernel. Right now, I’ve only compiled the kernel. I fully expect running a system with this EXACT patch will cause it to crash — so use … Read more
http://infocenter.arm.com/help/topic/com.arm.doc.prd29-genc-009492c/index.html is a pretty good introductory document that gives an overview of something a little bit too complex to be satisfactorily explained by typing into a text box. But I’ll try to answer your direct questions below. It refers to an additional privilege option orthogonal to the execution modes. Secure world has the ability to … Read more
I found a comment from Linus Torvalds that answers this question http://www.realworldtech.com/forum/?threadid=113923&curpostid=114068 The mapped pages are part of the filesystem cache, which means that even if the user process that made a change to that page dies, the page is still managed by the kernel and as all concurrent accesses to that file will go … Read more
This example will create a proc entry which enables reading access. I think you can enable other kinds of access by changing the mode argument passed to the function. I haven’t passed a parent directory because there is no need to. The structure file_operations is where you setup your reading and writing callbacks. struct proc_dir_entry … Read more
zram Status: Available in mainline kernel as of version 3.14 (March 2014) Implementation: compressed block device, memory is dynamically allocated as data is stored Usage: Configure zram block device as a swap device to eliminate need for physical swap defice or swap file Benefits: Eliminates need for physical swap device. This beame popular when netbooks … Read more
M is not an option for make. Note it lacks the hyphen. M is a variable assigned to the execution of make. If make executes a Makefile script, this script can read the variable M and use its contents. In the example you provide, make will read Makefile in ~/kernel-2.6 and assign your present working … Read more
The following statement in your question is wrong: What I know is that a part of the physical memory is reserved to communicate with the hardware A part of the physical memory is not reserved for communication with the hardware. A part of the physical address space, to which the physical memory and memory mapped … Read more