VisualDSP++ 4.5 Loader and Utilities Manual - Analog Devices

ADSP-2126x/2136x/2137x Processor Booting
The loader -compression switch directs the loader utility to perform the
boot stream compression from the command line. VisualDSP++ also
offers a dedicated loader property page (Load Compression) to manage
the compression from the graphical user interface.
The loader utility takes two steps to compress a boot stream. First, the
utility generates the boot stream in the conventional way (builds data
blocks), then applies the compression to the boot stream. The decompression
initialization is the reversed process: the loader utility decompresses
the compressed stream first, then loads code and data into memory segments
in the conventional way.
The loader utility compresses the boot stream on the .dxe-by-.dxe basis.
For each input .dxe file, the utility compresses the code and data together,
including all code and data from any associated shared memory (.sm) files.
The loader utility, however, does not compress automatically any data
from any associated overlay files. To compress data and code from the
overlay file, call the utility with the -compressionOverlay switch, either
from the property page or from the command line.
Compressed Streams
The basic structure of a loader file with compressed streams is shown in
Figure 5-5.
KERNEL WITH DECOMPRESSION ENGINE
1ST .dxe COMPRESSED STREAM
1ST .dxe UNCOMPRESSED STREAM
2ND .dxe COMPRESSED STREAM
2ND .dxe UNCOMPRESSED STREAM
. . .
. . .
Figure 5-5. Loader File with Compressed Streams
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