Normally the service processor is not necessary for debugging. However,
if you are using the hard-coded RCW or your boot source is otherwise
corrupt, then the general purpose processors will never be released from
hold-off. This will cause GDB to become confused if it tries to attach,
since they will appear to be running arm32 processors. To deal with
this, we can release the CPUs manually with the BRRL register. This
register cannot be written to from the axi target, so we need to do it
from the service processor target. This involves halting the service
processor, modifying the register, and then resuming it again. We try
and determine what state the service processor was in to avoid resuming
it if it was already halted.
The reset vector for the general purpose processors is determined by the
boot logation pointer registers in the device configuration unit.
Normally these are set using pre-boot initialization commands, but if
they are not set then they default to 0. This will cause the CPU to
almost immediately hit an illegal instruction. This is fine because we
will almost certainly want to attach to the processor and load a program
anyway.
I considered adding this as an event handler for either gdb-attach or
reset-init. However, this command shouldn't be necessary most of the
time, and so I don't think we should run it automatically.
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Change-Id: I1b725292d8a11274d03af5313dc83678e10e944c
Reviewed-on: https://review.openocd.org/c/openocd/+/6850
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Prerequisites:
The users of OpenOCD as well as computer programs interacting with OpenOCD are expecting that certain commands
do the same thing across all the targets.
Rules to follow when writing scripts:
1. The configuration script should be defined such as , for example, the following sequences are working:
reset
flash info <bank>
and
reset
flash erase_address <start> <len>
and
reset init
load
In most cases this can be accomplished by specifying the default startup mode as reset_init (target command
in the configuration file).
2. If the target is correctly configured, flash must be writable without any other helper commands. It is
assumed that all write-protect mechanisms should be disabled.
3. The configuration scripts should be defined such as the binary that was written to flash verifies
(turn off remapping, checksums, etc...)
flash write_image [file] <parameters>
verify_image [file] <parameters>
4. adapter speed sets the maximum speed (or alternatively RCLK). If invoked
multiple times only the last setting is used.
interface/xxx.cfg files are always executed *before* target/xxx.cfg
files, so any adapter speed in interface/xxx.cfg will be overridden by
target/xxx.cfg. adapter speed in interface/xxx.cfg would then, effectively,
set the default JTAG speed.
Note that a target/xxx.cfg file can invoke another target/yyy.cfg file,
so one can create target subtype configurations where e.g. only
amount of DRAM, oscillator speeds differ and having a single
config file for the default/common settings.
Sean Anderson
d1278660af