| 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 |
| |
| -------------------------------------------------------------------------------- |
| |
| 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 |
| |
| -------------------------------------------------------------------------------- |
| |
| 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 |
| |
| -------------------------------------------------------------------------------- |
| |
| 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 |
