23ebd514c1
Timers aren't firing yet so the system locks up as soon as any timeout is involved. Enough to run the command line for a bit.
44 lines
1.1 KiB
ArmAsm
44 lines
1.1 KiB
ArmAsm
/*
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* Copyright (c) 2019 Travis Geiselbrecht
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*
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* Use of this source code is governed by a MIT-style
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* license that can be found in the LICENSE file or at
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* https://opensource.org/licenses/MIT
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*/
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#include <lk/asm.h>
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// void vax_context_switch(struct vax_pcb *newpcb);
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FUNCTION(vax_context_switch)
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.word 0 // nothing saved
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// on the old stack save the current PSL and the PC to the exit of this function,
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// to be popped by the svpctx instruction
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movpsl -(%sp)
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moval .Lreturn, -(%sp)
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// load the new pcb into r0
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movl 4(%ap),%r0
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// save the full state of the cpu, switching to interrupt stack
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svpctx
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mtpr %r0,$0x10 // load the new PCBB
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// load new process context, leaves the new PSL and PC on the stack
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ldpctx
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// return to the new thread
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rei
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.Lreturn:
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// when an old thread is switch back to, arrange for the return address to be here
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ret
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// trampoline when initially starting a thread to get from a fake saved process
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// context to the C world, which requires a calls instruction.
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.globl vax_initial_thread_func
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vax_initial_thread_func:
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calls $0,initial_thread_func
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halt
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