[Profiling] DS-5

• What is ARM DS-5?
• Install
• .config: 建立 kernel config, timer, interrupt, tracers
• *.ko:
• gator:
• gatord:
• download ARM DS-5
• Reference:

[Development] using GNU development tools

• SOP

configure
make
make install

Configure

Build

• universal binary: 
• build flag: e.g.

  --arch ppc --arch i386

Install

Reference:

• porting Unix/Linux Applications to MacOSX

[Node.js] framework: Express

Install

• library
  • $npm install express -g
• binary generator
  • $npm install express-generator -g

• Usage
  • generate template app
    • $express --view=ejs sampleExpress
  • install dependencies:
    • $cd sampleExpress && npm install
  • run the app
    • $DEBUG=sampleExpress:* npm start
  • validate
    • jshint

[Kernel] Linux kernel debug

• 技巧
• 用 printk dump messages to console
• 簡單好用, 行為類似 printf, 不過這會改變 kernel行為 (例如: 執行速度變慢, 使得 race condition 行為不一致)
• 可同時更改 ring buffer size (更改 kernel boot parameter: log_buf_len), 避免 log的訊息被裁斷
• 更改 log level, 預設為 KERN_WARNING, e.g. 開啟所有 log:
, 並刪除 boot parameters: quiet, splash (runtime 查看 boot parameters: cat /proc/cmdline)
echo 7 > /proc/sys/kernel/printk
• 用 gdb
• disassemble function codes
• gdb vmlinux
(gdb) dissemble functionName
• locate core dump:
• gdb crashed_function_obj, e.g. gdb sd.o
• (gdb) list *(backtrace_func_shown+offset), e.g. list *(sd_remove+0x20
• 用 objdump
• objdump -SdCg sample.o
• ToDo: add2line 指令介紹, ELF 格式介紹, study Kernel Debugging
• Reference
• KernelDebuggingTricks