pSOSystem System Calls - Read

pSOS+ System Calls i_enter
i_enter Enters into an interrupt service routine.
This function cannot be called from a high-level language.
Description
Target
Return Value
Notes
This pSOS+ service entry is available only on x86, ColdFire, and PowerPC
processors. On these processors, i_enter() provides and establishes a standard
entrance convention for all interrupt service routines (ISRs). For efficiency reasons,
i_enter() is different from other system calls in that it uses a separate entry into
the pSOS+ kernel.
Entering the ISR
CF
PPC
x86
For more information, please refer to the examples given in the i_return() call
description on page 1-35.
None.
On ColdFire processors, i_enter() must be called at the beginning of
an ISR so that pSOS+ can keep track of nested interrupts and can
switch stacks if an interrupt stack is being used. i_enter() is called
via TRAP #12.
On PowerPC processors, i_enter() must be called at the beginning of
an ISR before the interrupt is re-enabled. The i_enter() entry point is
located at offset 0x60 from the beginning of the pSOS+ kernel code. It’s
called with a call (bl) instruction.
On x86 processors, i_enter() must be used as the first instruction of
an ISR, so that pSOS+ can keep track of nested interrupts and can
switch stacks if an interrupt stack is being used. i_enter() is called
via INT 92H.
i_return() must be used to exit an ISR.
pSOSystem System Calls 1-33
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