On Thu, 8 Apr 2004, Babbellapati Syam Krishna (IFIN DC COM) wrote: > During my target boot up, I could see the following message getting printed Which board/processor? > Memory: 12660k/12928k available (1689k kernel code, 268k reserved, 1512k > data, 72k init, 0k highmem) the following is my understanding. Correct me if I am wrong. The bootup time, bios/bootloader passses the memory information to kernel, usually in the first page.(ppcboot does it in a structure, i forgot the name of this structure). In i386 also you can view the memory map during bootup. Not all memory is available for the kernel. Some may be mapped to the ROM of board, vram, ISA card memory ..etc. This is reserved memory. Kernel may later map this into some linear address space and use it. > I would like to know what is this reserved memory of 268K? > AFAIK, it is static kernel data structures (please correct me if I am > wrong). > > Is there any way of knowing how much reserved memory a kernel would need by > looking at the compile time size of the vmlinux? Is this reserved memory > configurable kind of a thing? How much importance should we attach to this > reserved memory once the boot process is complete? Is this reserved memory > completely released for use to the applications? Not possible to fin it out by looking into compiled kernel. It must be hardware configurable, maybe putting different chipsets ;-) -- Omanakuttan.N. Perl, C, C++. Linux Anyone who says he can see through women is missing a lot. -- Groucho Marx -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
