Booting Process
19-30
ADSP-BF537 Blackfin Processor Hardware Reference
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 19-26
, a set of Boot ROM functions
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
. Register
R7
simply requires the number of the boot
stream to be loaded. The parameter passed in
R6
tells the function where
to find the chain of boot streams.
#include <defBF537.h> /* provides function entry addresses */
P0.H = HI(_BOOTROM_Get_DXE_Address_Flash) ;
P0.L = LO(_BOOTROM_Get_DXE_Address_Flash) ;
R7 = 2 (Z) ; /* DXE #3 - start counting from zero */
R6.H = HI(0x20000000) ; /* start of async bank 0 */
R6.L = LO(0x20000000) ;
CALL (P0) ; /* call to Boot ROM */
/* start address of DXE #3 is returned in R7 */
/* R7 is passed to the next function */
P0.L = LO(_BOOTROM_Boot_DXE_Flash) ;
JUMP (P0) ; /* boot DXE #3 */
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.
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...