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项目作者： kylemanna

项目描述 ：
Python interface to /dev/mem
高级语言： Python
项目地址: git://github.com/kylemanna/pydevmem.git
创建时间： 2011-11-28T06:52:24Z
项目社区：https://github.com/kylemanna/pydevmem
开源协议：MIT License
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Python DevMem

This is designed primarily for use with accessing /dev/mem on OMAP platforms.
It should work on other platforms and work to mmap() files rather then just
/dev/mem, but these use cases aren’t well tested.

All file accesses are aligned to DevMem.word bytes, which is 4 bytes on ARM
platforms to avoid data abort faults when accessing peripheral registers.

Usage

  1. Usage: devmem.py [options]
  3. Options:
  4.   -h, --help            show this help message and exit
  5.   -r ADDR, --read=ADDR  read a value
  6.   -w ADDR VALUE, --write=ADDR VALUE
  7.                         write a value
  8.   -n NUM, --num=NUM     number of words to read
  9.   -s WORD_SIZE, --word-size=WORD_SIZE
  10.                         size of word when displayed
  11.   -m FILE, --mmap=FILE  file to open with mmap()
  12.   -v                    provide more information regarding operation
  13.   -d                    provide debugging information

Speed

Initial testing on a BeagleBoard-xM (Cortex-A8 in a TI DM3730) shows that
starting up the python interpreter is pretty slow:

  1. # time (echo | python)
  3. real    0m0.859s
  4. user    0m0.750s
  5. sys     0m0.102s
  7. # time python ./pydevmem.py -r 0x4830a204 -n 8
  8. 0x4830a204:   1b89102f  00000000  00000000  000000f0
  9. 0x4830a214:   cafeb891  0c030016  015739eb  1ff00000
  11. real    0m1.109s
  12. user    0m0.977s
  13. sys     0m0.133s
  15. # time python -S ./pydevmem.py -r 0x4830a204 -n 8
  16. 0x4830a204:   1b89102f  00000000  00000000  000000f0
  17. 0x4830a214:   cafeb891  0c030016  015739eb  1ff00000
  19. real    0m0.659s
  20. user    0m0.602s
  21. sys     0m0.047s
  23. # time python -S ./pydevmem.pyc -r 0x4830a204 -n 8
  24. 0x4830a204:   1b89102f  00000000  00000000  000000f0
  25. 0x4830a214:   cafeb891  0c030016  015739eb  1ff00000
  27. real    0m0.647s
  28. user    0m0.508s
  29. sys     0m0.133s

System information for those tests:

  1. Linux omap 3.0.6-x3 #1 SMP Wed Oct 5 07:19:24 UTC 2011 armv7l GNU/Linux
  3. python              2.7.2-7ubuntu2
  4. python-configobj    4.7.2+ds-3
  5. python-minimal      2.7.2-7ubuntu2
  6. python2.7           2.7.2-5ubuntu1
  7. python2.7-minimal   2.7.2-5ubuntu1

Something needs to be sped up to make python start-up in a reasonable amount
of time.