Analog Devices Blackfin ADSP-BF537 Hardware Reference Manual page 1016

Booting Process
utility, they might be appended one after another and the start addresses
vary on build variables. When the individual boot streams are chained by
the Next DXE Pointer (NDP) scheme as described in
(Multi-DXE) Management" on page
help to determine the start addresses of the individual boot streams.
Again, different functions are available for the three master boot modes.
The user is responsible for initializing the stack and saving and restoring
all needed registers prior to calling these functions.
The following example boots the third boot stream contained in the flash
connected to
AMS0
stream to be loaded. The parameter passed in
to find the chain of boot streams.
#include <defBF537.h>
P0.H = HI(_BOOTROM_Get_DXE_Address_Flash) ;
P0.L = LO(_BOOTROM_Get_DXE_Address_Flash) ;
R7 = 2 (Z) ;
R6.H = HI(0x20000000) ;
R6.L = LO(0x20000000) ;
CALL (P0) ;
P0.L = LO(_BOOTROM_Boot_DXE_Flash) ;
JUMP (P0) ;
While parsing the chain the function tests for every individual boot stream
whether it is homed in an 8-bit or a 16-bit device. Therefore the chain
may cross different memory types heterogeneously. However, the data
width must not change within the same boot stream.
19-30
. Register simply requires the number of the boot
R7
/* provides function entry addresses */
/* DXE #3 - start counting from zero */
/* start of async bank 0 */
/* call to Boot ROM */
/* start address of DXE #3 is returned in R7 */
/* R7 is passed to the next function */
/* boot DXE #3 */
ADSP-BF537 Blackfin Processor Hardware Reference
"Multi-Application
19-26, a set of Boot ROM functions
tells the function where
R6