112 lines
2.8 KiB
ArmAsm
112 lines
2.8 KiB
ArmAsm
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; crt0_2.s - Startup code for the mrisc1. This code initializes the C
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; run-time model.
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;
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; Copyright 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
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;
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; The authors hereby grant permission to use, copy, modify, distribute,
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; and license this software and its documentation for any purpose, provided
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; that existing copyright notices are retained in all copies and that this
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; notice is included verbatim in any distributions. No written agreement,
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; license, or royalty fee is required for any of the authorized uses.
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; Modifications to this software may be copyrighted by their authors
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; and need not follow the licensing terms described here, provided that
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; the new terms are clearly indicated on the first page of each file where
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; they apply.
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;
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; Create a label for the start of the eh_frame section.
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.section .eh_frame
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__eh_frame_begin:
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.text
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.global _start
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_start:
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;; Initialize the stack pointer
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ldui sp, #%hi16(__stack)
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addui sp, sp, #%lo16(__stack)
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or fp, sp, sp
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;; Zero the bss space
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ldui r9, #%hi16(__bss_start)
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addui r9, r9, #%lo16(__bss_start)
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ldui r10, #%hi16(__bss_end)
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addui r10, r10, #%lo16(__bss_end)
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or r0, r0, r0
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brle r10, r9, .Lnext1
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or r0, r0, r0
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.Lcpy0:
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stw r0, r9, #0
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addi r9, r9, #4
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or r0, r0, r0 ; nop
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brle r9, r10, .Lcpy0
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or r0, r0, r0 ; nop
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.Lnext1:
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;; Copy data from ROM to Frame Buffer (on-chip memory)
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ldui r9, #%hi16(_fbdata_start)
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ori r9, r9, #%lo16(_fbdata_start)
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ldui r10, #%hi16(_fbdata_end)
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ori r10, r10, #%lo16(_fbdata_end)
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ldui r11, #%hi16(_fbdata_vma)
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brle r10, r9, .Lnext2
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ori r11, r11, #%lo16(_fbdata_vma)
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.Lcpy1:
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ldw r5, r9, #$0
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addi r9, r9, #$4
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stw r5, r11, #$0
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brlt r9, r10, .Lcpy1
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addi r11, r11, #$4
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.Lnext2:
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;; Zero the frame buffer bss section
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ldui r9, #%hi16(_fbbss_start)
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ori r9, r9, #%lo16(_fbbss_start)
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ldui r10, #%hi16(_fbbss_end)
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ori r10, r10, #%lo16(_fbbss_end)
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or r0, r0, r0
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brle r10, r9, .Lnext3
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or r0, r0, r0
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.Lcpy2:
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stw r0, r9, #$0
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addi r9, r9, #$4
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or r0, r0, r0
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brle r9, r10, .Lcpy2
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or r0, r0, r0
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.Lnext3:
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;; Call global and static constructors
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ldui r10, #%hi16(_init)
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ori r10, r10, #%lo16(_init)
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or r0, r0, r0 ; nop
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jal r14, r10
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or r0, r0, r0 ; nop
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;; Call main
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ldui r10, #%hi16(main)
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ori r10, r10, #%lo16(main)
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or r0, r0, r0 ; nop
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jal r14, r10
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or r0, r0, r0 ; nop
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;; DJK - Added 12Nov01. Pass main's return value to exit.
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or r1, r11, r0
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;; Jump to exit
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ldui r10, #%hi16(exit)
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ori r10, r10, #%lo16(exit)
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or r0, r0, r0 ; nop
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jal r14, r10
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or r0, r0, r0 ; nop
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;; Exit does not return, however, this code is to catch an
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;; error if it does. Set the processor into sleep mode.
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ori r1, r0, #$1
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stw r1, r0, #%lo16(_DEBUG_HALT_REG)
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or r0, r0, r0
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or r0, r0, r0
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or r0, r0, r0
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or r0, r0, r0
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or r0, r0, r0
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.Lend:
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jmp .Lend
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or r0, r0, r0
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