Exception Registers Block

OS SWI Calls

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» Exception Registers Block

Exception Registers Block

The exception registers block is used by the default implementation of environment handlers 1 to 5 as the location to save the ARM register dump, prior to the fault being announced via OS_GenerateError. Unlike the other environment handlers it is not a pointer to code; it is a pointer to a block of memory.

On 26bit systems the block must be 16 words long, and will contain R0-R15.

On 32bit systems the block must be 17 words long, and will contain R0-R15 and the PSR.

The register dump will only contain the registers for the mode in which the exception occurred.

Notes

From time to time other system components might write to the register block, e.g. when a floating point instruction raises a division by zero error.

See also

• OS_ChangeEnvironment