I finally understand why same parameter even has multiple locations. My pass concept is parameter stay in the stack. But after hacking the dwarf, it show me same parameter have multiple location during execution. Take a look below image, I wrote a function call kmalloc2 (blue arrow), the third parameter “size” has three locations (yellow […]

Elf is having duplicate compile unit, why ld doesn’t clear it out?

Without “CXXFLAGS=-O3”, boots can only runs 20M ips on my i5 mbpr. With that, now is 57M ips.

I am unable to get the “” from the input stream. Please help. In command line, when i start bochs, I saw “”, which is very normal. But if i use java to read it out, i never got the . I tried different classes (BufferedReader, InputStream), none of them success.

This tutorial teach you how to add a debug command in boots, you need to touch these files only: debug.h dbg_main.cc lexer.l parser.y Step 1) First of all, you need to add your command (see below) to lexer.l, don’t add anything below the line “[A-Za-z_][A-Za-z0-9_]* { bxlval.sval = strdup(bxtext); return(BX_TOKEN_GENERIC); }”, because it will eat […]

bochs can’t compile in mac because the configure always set gui_debugger=1, just set this variable to 0 in line 22459. Bochs can be compile in mac with “./configure –enable-disasm –with-sdl –enable-debugger”

openocd with arm is working

Finally connect my openjtag usb device to my old smartarm 2200 development board using openocd. The next step is buy a x86 dev board (intel galileo) and try to use openocd with it. Then port peter-bochs to support openocd, finally i will have a hardware debug platform for os dev. http://www.zlgmcu.com is a development board […]

People always ask me why their virtual address is not pointing to the right physical address. Almost every time is the page table get wrong. But there are few possibilities, such as PD, CR address and etc.. You can use these step to find out. 1) First, set the physical point and run until the […]