VisualDSP++ 4.5 Loader and Utilities Manual - Analog Devices

Blackfin Processor Booting
ADSP-BF561/BF566 Dual-Core Application Management
A typical ADSP-BF561/BF566 dual-core application is separated into two
executable files; one for each core. The default linker description (.ldf)
file for the ADSP-BF561/BF566 processor creates two separate executable
files (p0.dxe and p1.dxe) and some shared memory files (sml2.sm and
sml3.sm). By modifying the LDF, it is possible to create a dual-core
application that combines both cores into a single .dxe file. This is not
recommended unless the application is a simple assembly language program
which does not link any C run-time libraries. When using shared
memory and/or C run-time routines on both cores, it is best to generate a
separate .dxe file for each core. The loader utility combines the contents
of the shared memory files (sml2.sm, sml3.sm) only into the boot stream
generated from the .dxe file for core A (p0.dxe).
The boot ROM only loads one single executable before the ROM jumps
to the start of core A instruction SRAM (0xFFA0 0000). When two .dxe
files are loaded, a second-stage loader is used. The second-stage boot
loader must start at 0xFFA0 0000. The boot ROM loads and executes the
second-stage loader. A default second-stage loader is provided for each
boot mode and can be customized by the user.
Unlike the initialization blocks, the second-stage loader takes full control
over the boot process and never returns to the boot ROM.
The second-stage loader can use the .dxe byte count blocks to find specific
.dxe files in external memory if a loader file includes the codes and
data from a number of .dxe files.
� The
default second-stage loader uses the last 1024 bytes of L2
memory. The area must be reserved during booting but can be
reallocated at runtime.
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