Title: Boot Time Measurement
Description:
BootTime measures the time:
a) from system reset to kernel start (crt0.s's __start)
b) from kernel start to begin of main()
c) from kernel start to begin of first task
The project can be built using one of the following three configurations:
best
-------
- Disables most features
- Provides best case boot measurement
default
-------
- Default config options
- Provides typical boot measurement
worst
-------
- Enables most features
- Provides worst case boot measurement
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Building and Running Project:
This nanokernel project outputs to the console. It can be built and executed
on QEMU in three possibile configurations as follows:
make BOOTTIME_QUALIFIER=best qemu
make BOOTTIME_QUALIFIER=default qemu
make BOOTTIME_QUALIFIER=worst qemu
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Troubleshooting:
Problems caused by out-dated project information can be addressed by
issuing one of the following commands then rebuilding the project:
make clean # discard results of previous builds
# but keep existing configuration info
or
make pristine # discard results of previous builds
# and restore pre-defined configuration info
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Sample Output:
tc_start() - Boot Time Measurement
NanoKernel Boot Result: Clock Frequency: 20 MHz
__start : 377787 cycles, 18889 us
_start->main(): 5287 cycles, 264 us
_start->task : 5653 cycles, 282 us
Boot Time Measurement finished
===================================================================
PASS - bootTimeTask.
===================================================================
PROJECT EXECUTION SUCCESSFUL
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