protected-mode | 易学教程

Assembler jump in Protected Mode with GDT

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问题 I am currently playing around with x86 Assember in order to sharpen my low-level programming skills. Currently, I am facing a little problem with the addressing scheme in 32-Bit Protected Mode. The situation is the following: I have a Program loaded at 0x7e0 which switches the CPU to Protected Mode and jumps to the according label in the code: [...] code to switch CPU in Protected Mode [...] jmp ProtectedMode [...] bits 32 ProtectedMode: .halt: hlt jmp .halt This works absolutely fine so far.

Protected Mode Keyboard Access on x86 Assembly

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I'm working on keyboard input for a very basic kernel that I'm developing and I'm completely stuck. I can't seem to find any information online that can show me the information I need to know. My kernel is running in protected mode right now, so I can't use the real mode keyboard routines without jumping into real mode and back, which I'm trying to avoid. I want to be able to access my keyboard from protected mode. Does anyone know how to do this? The only thing I have found so far is that it involves talking to the controller directly using in/out ports, but beyond that I'm stumped. This is,

Constant reboot after setting up the Global Descriptor Table and protected mode

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问题 I must have done something wrong with the GDT setup and the switch to protected mode because it keeps constantly rebooting. Here is my kernel.asm that should setup the GDT and switch to protected mode : bits 16 jmp main %include "gdt.inc" main: cli xor ax,ax mov ds,ax mov es,ax mov ax,0x9000 mov ss,ax mov sp,0xffff sti call InstallGDT cli mov eax,cr0 or eax,1 jmp 08h:Stage3 bits 32 Stage3: mov ax,0x10 mov ds,ax mov ss,ax mov es,ax mov esp,90000h Stop: mov byte [0xb8000],'A' cli hlt and there

How to Access AppData in IE Protected Mode (from a Managed BHO)

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问题 I am writing an IE Extension (BHO) in C#. When run in protected mode (IE's new UAC-compliant mode which forces all extensions to run at low-integrity), it fails because it cannot access user.config in the appdata folder. Is there some way to mark files are readable by lower-integrity processes? Failing that, is there some way to force the BHO to run at medium-level integrity? Failing that, is there some way to create a low-integrity symlink in the low-integrity folders which points to a