166 lines
3.2 KiB
ArmAsm
166 lines
3.2 KiB
ArmAsm
/*
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* LatticeMico32 C startup code.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/* Exception handlers - Must be 32 bytes long. */
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.section .text, "ax", @progbits
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.global _start
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_start:
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_reset_handler:
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xor r0, r0, r0
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wcsr IE, r0
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mvhi r1, hi(_reset_handler)
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ori r1, r1, lo(_reset_handler)
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wcsr EBA, r1
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bi _crt0
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nop
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nop
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_breakpoint_handler:
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bi _breakpoint_handler
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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_instruction_bus_error_handler:
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bi _instruction_bus_error_handler
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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_watchpoint_hander:
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bi _watchpoint_hander
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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_data_bus_error_handler:
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bi _data_bus_error_handler
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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_divide_by_zero_handler:
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bi _divide_by_zero_handler
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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_interrupt_handler:
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sw (sp+0), ra
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calli .save_all
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calli isr
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bi .restore_all_and_eret
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nop
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nop
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nop
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nop
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_syscall_handler:
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bi _syscall_handler
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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_crt0:
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/* Setup stack and global pointer */
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mvhi sp, hi(_fstack)
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ori sp, sp, lo(_fstack)
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mvhi gp, hi(_gp)
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ori gp, gp, lo(_gp)
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/* Clear BSS */
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mvhi r1, hi(_fbss)
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ori r1, r1, lo(_fbss)
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mvhi r3, hi(_ebss)
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ori r3, r3, lo(_ebss)
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.clearBSS:
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be r1, r3, .callMain
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sw (r1+0), r0
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addi r1, r1, 4
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bi .clearBSS
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.callMain:
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bi main
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.save_all:
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addi sp, sp, -56
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sw (sp+4), r1
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sw (sp+8), r2
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sw (sp+12), r3
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sw (sp+16), r4
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sw (sp+20), r5
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sw (sp+24), r6
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sw (sp+28), r7
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sw (sp+32), r8
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sw (sp+36), r9
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sw (sp+40), r10
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sw (sp+48), ea
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sw (sp+52), ba
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/* ra needs to be moved from initial stack location */
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lw r1, (sp+56)
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sw (sp+44), r1
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ret
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.restore_all_and_eret:
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lw r1, (sp+4)
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lw r2, (sp+8)
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lw r3, (sp+12)
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lw r4, (sp+16)
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lw r5, (sp+20)
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lw r6, (sp+24)
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lw r7, (sp+28)
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lw r8, (sp+32)
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lw r9, (sp+36)
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lw r10, (sp+40)
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lw ra, (sp+44)
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lw ea, (sp+48)
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lw ba, (sp+52)
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addi sp, sp, 56
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eret
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