I have to make an rtos for 8051.
1.what are the functions performed by bootloader during startup of the chip? if i can execute a program on my chip stored at any location in memory then what do i mean by making a separate OS for 8051?
please help me..
regards, M.Stephen Selvaraj
The Real Time part is that the OS is deterministic.
The threads that have hard requirements are guaranteed to be started fast enough to never miss an event.
In some situations, the requirement is in ns - which means we need dedicated hardware.
In some situations, it is in us, which mean we can use the highest prioritized interrupt, as long as we know that the longest time interrupts are disabled + the response time of the most prioritized interrupt handler is less than our requirement.
In some situations the requirement is in ms, so we can use threads with high priority and let the OS switch in the task based on the trigger event.
The Real Time part is that the system can always manage the requirement. Or - in some situations - it may be accepted that it sometimes fails, as long as the system always knows when it has failed and can guarantee that it can perform an alternative (such as a corrective action) within a guaranteed time.
In the end, an RTOS doesn't need to be fast. It just has to prommise a max response time. The advantage of a fast RTOS is that a slower (cheaper and/or less power-consuming) processor may be used for a specific timing requirement.