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