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author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2011-05-28 21:42:18 +0000 |
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committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2011-05-28 21:42:18 +0000 |
commit | 94c7babe23d72a1e379da0cf0aab32fcf9fadcf3 (patch) | |
tree | eedc930a4ed4a1108c87cae26d3fcda7e411dd1f /nuttx/Documentation/NuttxPortingGuide.html | |
parent | 405c2b328ff4cd571bb9e464541b4d297b18f93d (diff) | |
download | px4-nuttx-94c7babe23d72a1e379da0cf0aab32fcf9fadcf3.tar.gz px4-nuttx-94c7babe23d72a1e379da0cf0aab32fcf9fadcf3.tar.bz2 px4-nuttx-94c7babe23d72a1e379da0cf0aab32fcf9fadcf3.zip |
atexit() functions now called when task killed by task delete; For MCUs with <= 64Kb of SRAM, CONFIG_MM_SMALL can be defined to reduce the memory allocation overhead
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3648 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/Documentation/NuttxPortingGuide.html')
-rw-r--r-- | nuttx/Documentation/NuttxPortingGuide.html | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/nuttx/Documentation/NuttxPortingGuide.html b/nuttx/Documentation/NuttxPortingGuide.html index fb06f794e..faa9f32cf 100644 --- a/nuttx/Documentation/NuttxPortingGuide.html +++ b/nuttx/Documentation/NuttxPortingGuide.html @@ -12,7 +12,7 @@ <h1><big><font color="#3c34ec"> <i>NuttX RTOS Porting Guide</i> </font></big></h1> - <p>Last Updated: May 25, 2011</p> + <p>Last Updated: May 28, 2011</p> </td> </tr> </table> @@ -3263,6 +3263,17 @@ build handle and enables the API mm_addregion(start, end); </li> <li> + <code>CONFIG_MM_SMALL</code>: Each memory allocation has a small allocation + overhead. The size of that overhead is normally determined by + the "width" of the address support by the MCU. MCUs that support + 16-bit addressability have smaller overhead than devices that + support 32-bit addressability. However, there are many MCUs + that support 32-bit addressability <i>but</i> have internal SRAM + of size less than or equal to 64Kb. In this case, CONFIG_MM_SMALL + can be defined so that those MCUs will also benefit from the + smaller, 16-bit-based allocation overhead. + </li> + <li> <code>CONFIG_MSEC_PER_TICK</code>: The default system timer is 100Hz or <code>MSEC_PER_TICK</code>=10. This setting may be defined to inform NuttX that the processor hardware is providing system timer interrupts at some interrupt |