2012-03-27

Materials

JOS

- http://pdos.csail.mit.edu/6.828/2011/lec/l-x86.pdf

- http://pdos.csail.mit.edu/6.828/2011/xv6/book-rev6.pdf

Highlight

- EIP modified by CALL, RET, JMP, and conditional JMP

Memory

Memory IO-mapped

- http://www.c-jump.com/CIS77/ASM/Memory/lecture.html

- http://en.wikipedia.org/wiki/Addressing_mode

PC emulator

- Emulation of Memory, CPU, Devices,

http://www.c-jump.com/CIS77/CIS77syllabus.htm

Emulation Model

- Register-based

ex: Dalvik VM

- Stack-based

ex: Java VMs (stack machine)

Interpreter

- switch

- label op code

...

If your lab1 is going on

You could try to reference: http://hawxchen.blogspot.com/search/label/MIT-6.828_OSE

Update collection of git repositories

git clone https://github.com/benwei/MIT-OSE-Labs.git

git submodule init

git submodule update

Qestions

why warm reboot after kernel start?

movw $0x1234, 0x472

reboot_mode samples

void reboot_setup(char *str, int *ints)

{

while(1) {

switch (*str) {

case 'w': /* "warm" reboot (no memory testing etc) */

reboot_mode = 0x1234;

break;

case 'c': /* "cold" reboot (with memory testing etc) */

reboot_mode = 0x0;

break;

case 'b': /* "bios" reboot by jumping through the BIOS */

reboot_thru_bios = 1;

break;

case 'h': /* "hard" reboot by toggling RESET and/or crashing the CPU */

reboot_thru_bios = 0;

break;

}

if((str = strchr(str,',')) != NULL)

str++;

else

break;

}

http://www.cab.u-szeged.hu/linux/kernel/linux/arch/i386/kernel/process.c.html

Disk I/O JOS

read_sect(): i/o port to access hard disk

Boot Mode

Now, for those of you familiar with the PC architecture, there seem to be some missing, including the famous warm-reset (0x1234 anybody?) software jump to the reset vector and the CPU-only reset (used for core-logic bus adjustments). In general, these other reasons are coerced into one of the above values.

有趣的是，連寫Bios的人都不見得知道為什是0x1234？

http://wiki.phoenix.com/wiki/index.php/Boot_Mode