From a33a21cde925e41ab435e34baf4255fd33fa2d4e Mon Sep 17 00:00:00 2001 From: pantonshire Date: Sun, 30 Jun 2024 09:22:48 +0100 Subject: [PATCH] update memory layout table --- boot0.s | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/boot0.s b/boot0.s index 2e99481..00db0aa 100644 --- a/boot0.s +++ b/boot0.s @@ -1,10 +1,20 @@ ; MEMORY LAYOUT -; 0x0000 - 0x7000: stack -; 0x7000 - 0x7c00: globals -; 0x7000 - 0x7001: boot drive number -; 0x7001 - 0x7002: number of hard disk drives -; 0x7002 - 0x7003: -; 0x7c00 - 0x7e00: boot sector +; R = reserved, U = usable +; -------------------------------------------------------------------- +; R | 0x000000 - 0x000400: real-mode interrupt vector table +; R | 0x000400 - 0x000500: bios data area +; U | 0x000500 - 0x007000: stack +; U | 0x007000 - 0x007c00: globals +; | 0x007000 - 0x007001: boot drive number +; | 0x007001 - 0x007002: number of hard disk drives +; | 0x007002 - 0x007003: +; U | 0x007c00 - 0x007e00: boot sector +; U | 0x007e00 - 0x080000: conventional usable memory +; R | 0x080000 - 0x0a0000: extended bios data area (maximum possible size) +; R | 0x0a0000 - 0x0c0000: video memory +; R | 0x0c0000 - 0x0c8000: video bios +; R | 0x0c8000 - 0x0f0000: bios expansiosn +; R | 0x0f0000 - 0x100000: motherboard bios ; BIOS puts our boot sector at 0000:7c00 org 0x7c00