Analog Devices VISUALDSP++ 3.5, Manual

Page: 96 / 166

ADSP-219x DSP Booting
3-10 Vi+ Loader Manual
for 16-Bit Processors
elfloader -proc ADSP-2191 -b PROM -width 16 app1.dxe
app2.dxe -pdAddrNext 0x20000
elfloader -proc ADSP-2191 -b PROM -width 8 -o flash.ldr -pd
0x20000 -p 0x20000 app3.dxe -pd 0x30000 app4.dxe
!
In cases where the
-pd
and
-p
values are expected to be the same,
you may specify
-pEqualPD
:
elfloader -proc ADSP-2191 -b PROM -width 16 app1.dxe
app2.dxe -pd 0x20000 -pEqualPD -width8 -o flash.ldr
app3.dxe -pd 0x30000 app4.dxe
With the
-NoDxeAddrHdr
switch, this artificial block is not inserted. Then
the user loader can still parse the complete boot stream, block by block
until it detects a final-init block. Since the default
-p
value is reset to a
zero whenever an
-o
is specified, the addresses in the Intel hex record has
to be explicitly set to
0x20000
for
flash.ldr
.
It is very likely that second-stage loaders and similar type of programs exe-
cute directly from the EPROM. Thus, this multiple
.DXE
scenarios are
often combined with the features discussed in “Enriching Boot EPROMs
with No-boot Data” on page 3-16 .
Host Booting
Host booting is performed in either an 8-bit or 16-bit scenario. By
default, little-endian format is used. If configured in Host boot mode, the
DSP does not support the boot process actively. It is the host’s responsi-
bility to initialize the DSP memories properly. The DSP passively waits
until the host writes a “
1
” to the Semaphore A register (IO address
0x1CFC
). Then the DSP starts fetching and executing instructions at
address
0x00 0000
.