OSDev.org

Posted: **Mon Jul 19, 2004 5:33 pm**

I'm writing a little OS, and currently I'm facing the Memory Management challenge. I've understood everything about how paging works, and etc, but I can't seem to get which addresses that are free mapable memory, and what's not (BIOS ROM (horribly if I try writing to that), PCI memory etc...).

In simple words, what can I use as free memory, and how do I determine how much allocateable memory a machine has?

Help is appreciated!

Posted: **Mon Jul 19, 2004 7:44 pm**

This gets discussed every fortnight, and is in the FAQ.

Investigate int 15h, e820h/e801h/88h.

Posted: **Wed Jul 21, 2004 3:10 pm**

...or, if you're using GRUB, check the Multiboot specification (GRUB simplifies your life by calling those BIOS INTs for you).

OSDev.org

Available memory, taken memory, etc... How to determine?

Available memory, taken memory, etc... How to determine?

Re:Available memory, taken memory, etc... How to determine?

Re:Available memory, taken memory, etc... How to determine?