Setup — Preparing the SAMA5D3x-MB Board for eCos Development
In a typical development environment the SAMA5D3x-MB board is
programmed via a JTAG/SWD interface. This will either be by loading
smaller applications into the on-chip SRAM, or into suitably
initialised DDR2-SDRAM memory. Alternatively applications may be
loaded into bootable memory-mapped devices, e.g. EBI_CS0 NOR flash, or
loaded via the on-chip
RomBOOT code via a
second-level SRAM boot scheme. The following sections initially deal
with JTAG/SWD hardware based debugging approaches.
For debugging applications are loaded and then executed on the board via the debugger arm-eabi-gdb, or via the Eclipse IDE.
The SAMA5D3x-MB motherboard provides a built-in J-Link hardware debug solution, as well as optionally providing the J9 JTAG connector for attaching 3rd-party hardware debuggers (e.g. Ronetix PEEDI).
For the Ronetix PEEDI, the
file should be used to setup and configure the hardware to an
appropriate state to load programs. This includes setting up the PLLs
and SDRAM controller. You can also check the Ronetix website
for updated versions.
Use of a PEEDI debugger requires hardware modification of the standard SAMA5D3x-MB board, which will provide a 20-pin ARM JTAG connector at J9. The required modifications are detailed in the board's user manual.
sama5d31ek.peedi.cfg file also contains an
option to define whether hardware or software breakpoints are used by
default, using the
CORE0_BREAKMODE directive in
[PLATFORM_CortexA8] section (NOTE: The PEEDI
firmware identifies not just A8 CPUs with
CortexA8 tag). Edit this file if you wish to
use hardware break points, and remember to restart the PEEDI to make
the changes take effect.
On the PEEDI, debugging can be performed either via the telnet interface or using arm-eabi-gdb and the GDB interface. In the case of the latter, arm-eabi-gdb needs to connect to TCP port 2000 on the PEEDI's IP address. For example:
target remote 111.222.333.444:2000
By default when the PEEDI is powered up, the target will always run
the initialization section of
sama5d31ek.peedi.cfg file, and halts the
target. This behaviour is repeated with the
PEEDI reset command.
If the board is reset (either with the 'reset', or
by pressing the reset button) and the 'go' command
is then given, then the board will boot as normal. Depending on how
the platform jumper state is configured this could run either a
second-level bootstrap, or a
ROM RedBoot resident
By default the arm-eabi-gdb connection to
the PEEDI will default to displaying the
FPA registers. To enable access to
VFP registers a suitable target description
file should be configured prior to connecting to the target
system. This can either be done manually every time a GDB session is
started, or more sensibly embedded in the
.gdbinit used to configure GDB.
sama5d3x-tdesc.xml file can be used to define
the target description using the
GDB set tdesc filename
command. For example the
.gdbinit could contain
something similar to:
set tdesc filename $ECOS_REPOSITORY/packages/hal/arm/cortexa/sama5d3/sama5d3x_mb/current/misc/sama5d3x-tdesc.xml
So that it has the relevent target description available prior to the remote debug connection being established. This will allow access to the VFP registers via the PEEDI, for example via the GDB info all-reg command.
Consult the PEEDI documentation for information on other features.
|2021-09-02||eCosPro Non-Commercial Public License|