Guarded Control Stack switch stack 1
This instruction validates that the stack being switched to contains a Valid GCS cap record, stores an In-progress GCS cap record to the stack that is being switched to, and sets the current GCS pointer register to the stack that is being switched to.
If the instruction generates a synchronous Data Abort exception, Watchpoint exception, GPC exception, or GCS Data Check exception, the value of GCSPR_ELx for the current Exception level is restored to the value held in the register before the instruction was executed.
For more information, see GCSSS1, Guarded Control Stack Switch Stack 1.
This is an alias of SYS. This means:
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| 1 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 0 | Rt | ||||
| L | op1 | CRn | CRm | op2 | |||||||||||||||||||||||||||
The description of SYS gives the operational pseudocode for this instruction.
2026-03_rel 2026-03-26 20:48:11
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