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29 lines
796 B
ArmAsm
29 lines
796 B
ArmAsm
/* Copyright © 1995-2001, The AROS Development Team. All rights reserved.
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$Id$
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*/
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/*
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* Switch the processor into user mode.
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* Parameters to this function:
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* function to continue with afterwards.
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* pointer to the user stack to be used.
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*/
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.text
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.balign 16
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.globl switch_to_user_mode
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switch_to_user_mode:
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move.l 0x8(%sp),%a0 // get USP
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move.l %a0,%usp // set the USP to the new value
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move.l %ssp,%a1 // ssp->a1 for later to access
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lea.l in_user_mode,%a0// prepare a fake exception stack frame
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move.l %a0,-(%ssp) // PC
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move.w #0x0700,-(%ssp) // SR
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rte // get the PC and SR from the exception
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// stack frame
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in_user_mode:
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move.l 0x4(%a1),%a0 // a1 contains old ssp
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jmp (%a0) // jump to address where to continue
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