[SOLVED] how "zero-page" is used in handling virtual memory

SIG_SEGV · 08-30-2012, 11:55 PM

I am going through "Booting the kernel on PC" concept these days. It says:

At boot time after the kernel is decompressed, it is moved from address 0x10000 (64K) to 0x1000 (4K). This move overwrites BIOS data stored in RAM. The first physical page (0x0000 to 0x0FFF) is not touched because it is the so-called “zero-page”, used in handling virtual memory.

So, my question is how "zero-page" is used to handle virtual memory???

Ygrex · 08-31-2012, 02:37 AM

this address range handles «virtual» memory, that does not represent physical RAM space, but CPU vector page

SIG_SEGV · 08-31-2012, 03:28 AM

@Ygrex: Thank you very much..... Can you please elaborate more or suggest me a link

pan64 · 08-31-2012, 03:49 AM

probably this is what you need: http://lwn.net/images/pdf/LDD3/ch15.pdf