On x86 you would do the following (simplified): Have the bootloader load the n-th sector of the disk/floppy (wherever you’re booting from) into memory and execute it (i.e. load segment/offset and do retf). A better alternative is to search the filesystem for a certain filename (e.g. KERNEL.BIN) — but you’d need to know the file … Read more
DOS inherited CR-LF line endings (what you’re calling \r\n, just making the ascii characters explicit) from CP/M. CP/M inherited it from the various DEC operating systems which influenced CP/M designer Gary Kildall. CR-LF was used so that the teletype machines would return the print head to the left margin (CR = carriage return), and then … Read more
When they say map, they mean that each kernel thread is assigned to a certain number of user mode threads. Kernel threads are used to provide privileged services to applications (such as system calls ). They are also used by the kernel to keep track of what all is running on the system, how much … Read more
Linux x86 ring usage overview Understanding how rings are used in Linux will give you a good idea of what they are designed for. In x86 protected mode, the CPU is always in one of 4 rings. The Linux kernel only uses 0 and 3: 0 for kernel 3 for users This is the most … Read more
There are a lot of links after this brief overview of what is involved in writing an OS for the X86 platform. The link that appears to be most promising (www.nondot.org/sabre/os/articles) is no longer available, so you’ll need to poke through the Archive.org version to read it. At the end of the day the bootloader … Read more
They are NOT the same thing. They are used for different purposes! While both types of semaphores have a full/empty state and use the same API, their usage is very different. Mutual Exclusion Semaphores Mutual Exclusion semaphores are used to protect shared resources (data structure, file, etc..). A Mutex semaphore is “owned” by the task … Read more