67 lines
1.1 KiB
ArmAsm
67 lines
1.1 KiB
ArmAsm
/*
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* \brief Transition between kernel/userland
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* \author Sebastian Sumpf
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* \author Mark Vels
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* \date 2015-06-22
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*/
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/*
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* Copyright (C) 2015-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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.set CPU_IP, 0
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.set CPU_EXCEPTION, 8
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.set CPU_X1, 2*8
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.section ".text.crt0"
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# 0x100 user mode
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j _kernel_entry
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.p2align 8
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_kernel_entry:
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# client context
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csrrw x31, sscratch, x31
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# save x1 - x30
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.irp reg,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
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sd x\reg, CPU_X1 + 8 * (\reg - 1)(x31)
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.endr
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# trap reason
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csrr x30, scause
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sd x30, CPU_EXCEPTION(x31)
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# ip
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csrr x30, sepc
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sd x30, CPU_IP(x31)
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# x31
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csrr x30, sscratch
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sd x30, CPU_X1 + 8 * 30(x31)
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la x29, kernel_stack
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la x30, kernel_stack_size
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ld x30, (x30)
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add sp, x29, x30
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la x30, kernel
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jalr x30
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.section .text
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/*******************************
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** idle loop for idle thread **
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*******************************/
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.global idle_thread_main
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idle_thread_main:
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wfi
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j idle_thread_main
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