Home‎ > ‎2012讀書會‎ > ‎

2012-04-24

JuluOSDev 0424
原始資料:共筆用網路筆記本: http://sync.in/wIMmpS88Me

Ben

202         // Question: why need to memmove ?
203         memmove(e->env_pgdir, kern_pgdir, PGSIZE);
Answer: copy to user


Hawx

-        return ((pte_t *) KADDR (pde_pg->paddr)) + PTX (va);
 532
+        return  &pgtable[PTX(va)];//((pte_t *) KADDR (pde_pg->paddr)) + PTX (va);
==> 使用表單方式存取 pgtable, 看起來比較優美

值得一看的圖表


Jserv

Cortex-M3:  STM32


如何測量程式在嵌入式板子執行時間?
Ans: 使用外部電路,並利用另一台電腦來測量版子上的程式所花費的時間。

作業出題
    基本系統原始碼,改進其效能及檔案大小。
作業評分標準
    依程式大小
    依程式執行時間


L4ka

L4ka kernel debugger is very useful.

 entry.S exception entry
 
 Root task 

UTCB
User-leve control block


舉例來說,倘若系統存在兩個不同 address space 的執行單元 (如 UNIX Process),而其中一者 (userA) 想要存取另一者 (userB) 的記體體,只要將 userA 設置為 userB 的 pager (記憶體管理單元) 並提供 userB 的 page fault handler 即可。

linux thread control block size?

nachos

Nachos is instructional software for teaching undergraduate, and potentially
graduate, level operating systems courses.  The Nachos distribution
comes with: 

   an overview paper
   simple baseline code for a working operating system
   a simulator for a generic personal computer/workstation
   sample assignments
   a C++ primer (Nachos is written in an easy-to-learn subset of C++, 
     and the primer helps teach C programmers our subset)
 --> 較少硬體相關程式碼

Current researching Amber ARM

The Amber processor core is an ARM-compatible 32-bit RISC processor. The Amber core is fully compatible with the ARM® v2a instruction set architecture (ISA) and is therefore supported by the GNU toolset. This older version of the ARM instruction set is supported because it is still fully supported by the GNU tool chain and is not covered by patents so can be implemented without a license from ARM. The Amber project provides a complete embedded system incorporating the Amber core and a number of peripherals, including UARTs, timers and an Ethernet MAC. 
Comments