Memory map

meng zhou

In the article named "Changing the DVEVM memory map".

When arranging the segments in correct order and alignment, it says that we would place the "RESETCTRL" segment at the highest-addressed 1MB in the map and place "DSPLINKMEM" segment immediately after "RESETCTRL".

The position is like the Figure 2 in the article.

But it is different from the Figure 1. In the "before" picture, the position of RESETCTRL and DSPLINKMEM is different from the "after" picture. While the position of this two in the "before" picture is in conflict with the Figure 2.

I can't confirm which one is correct. Is the positon not important??

Who can tell me the answer??

over 14 years ago

0 Chris Ring over 14 years ago

TI__Genius 17205 points

In general, the order doesn't matter. There are some memory sections that have some constraints - for example, the RESET_VECTOR must be 1MB aligned. And I think the Linux _base_ addr must be 16MB aligned and the size must be an interval of 1MB.

If you want, you can even punch a hole in Linux memory and have it span two disjoint blocks. Similarly, with CMEM's 'multiple block' support (introduced in Linux Utils 2.20), you can have 2 blocks managed by CMEM. That just shows some of the flexibility you have.

Figure one in that article is showing the before and after of some optimizations. One of the optimizations it describes is to place the ~1MB DSPLINKMEM block in the ~1MB UNUSED memory following the small RESET_VECTOR. That's why before and after look different.

Chris

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Memory map