RAM 6.0 BUX II Series Guia do Utilizador Página 77

  • Descarregar
  • Adicionar aos meus manuais
  • Imprimir
  • Página
    / 189
  • Índice
  • MARCADORES
  • Avaliado. / 5. Com base em avaliações de clientes
Vista de página 76
3 Porting a BSP to Custom Hardware
3.2 Getting a Minimal Kernel Running
69
3
3.2.6 Building and Downloading VxWorks
The VxWorks image you load to the target depends on the download method you
use. The primary images are as follows:
vxWorks
This image starts execution from RAM. It must be loaded into RAM by some
external means such as the board’s native debug ROMs.
vxWorks_rom
This image starts execution from ROM, but its text and data segments are
linked to RAM addresses. Early in the initialization process, it copies itself into
RAM and continues execution from that point.
vxWorks_resrom_nosym
This image executes from ROM. Only the data segment is copied into RAM.
For additional image types, see 2.2.2 Boot Sequence Configurations, p.11.
If your download path puts the image in RAM (such as when using a vendor
debug ROM), use the vxWorks image. If your download path puts the image in
ROM (such as when using NetROM), use either vxWorks_rom or
vxWorks_resrom_nosym. The advantage of vxWorks_rom is that it can be more
easily debugged because software breakpoints can only be set on RAM addresses.
The advantage of vxWorks_resrom_nosym is that it uses less target memory. The
makefile for both ROM images lets you specify an optional .hex suffix (for
example, vxWorks_rom.hex) to produce an S-record file, in addition to the object
file.
There is a file called depend.cputool that contains the file dependency rules used
by the makefile. If this dependency file does not already exist, the makefile
automatically generates it. If you add new files to the BSP, delete the dependency
file and let the makefile generate a new file.
After you have downloaded your code to the target, examine memory or ROM to
make sure that the code is loaded in the right place. Use the nm and objdump
utilities on the VxWorks image to compare what should be in the target memory
with what is actually there. Pay special attention to the start addresses of the text
and data segments.
For additional information on building and downloading VxWorks, see the
appropriate VxWorks programmer’s guide.
Vista de página 76
1 2 ... 72 73 74 75 76 77 78 79 80 81 82 ... 188 189

Comentários a estes Manuais

Sem comentários