; crt0_2.s - Startup code for the mrisc1. This code initializes the C
|
; crt0_2.s - Startup code for the mrisc1. This code initializes the C
|
; run-time model.
|
; run-time model.
|
;
|
;
|
; 12Nov01 (DJK) - The return code from main was not being passed to exit().
|
; 12Nov01 (DJK) - The return code from main was not being passed to exit().
|
; Now it is passed as a parameter in R1.
|
; Now it is passed as a parameter in R1.
|
;
|
;
|
; 10Sep01 (DJK) - The function exit() does not return. However, in the
|
; 10Sep01 (DJK) - The function exit() does not return. However, in the
|
; the case of device error (if the halt bit does not
|
; the case of device error (if the halt bit does not
|
; function properly, for instance), then a catch loop
|
; function properly, for instance), then a catch loop
|
; has been added.
|
; has been added.
|
;
|
;
|
;
|
;
|
; Copyright 2001, 2002, 2003, 2004 Morpho Technologies, Inc.
|
; Copyright 2001, 2002, 2003, 2004 Morpho Technologies, Inc.
|
;
|
;
|
|
|
; Create a label for the start of the eh_frame section.
|
; Create a label for the start of the eh_frame section.
|
.section .eh_frame
|
.section .eh_frame
|
__eh_frame_begin:
|
__eh_frame_begin:
|
|
|
.equ HALT_REG, 0x300
|
.equ HALT_REG, 0x300
|
.section .text
|
.section .text
|
.global _start
|
.global _start
|
_start:
|
_start:
|
;; Initialize the stack pointer
|
;; Initialize the stack pointer
|
ldui sp, #%hi16(__stack)
|
ldui sp, #%hi16(__stack)
|
addui sp, sp, #%lo16(__stack)
|
addui sp, sp, #%lo16(__stack)
|
or fp, sp, sp
|
or fp, sp, sp
|
|
|
;; Copy data from ROM to Frame Buffer (on-chip memory)
|
;; Copy data from ROM to Frame Buffer (on-chip memory)
|
ldui r9, #%hi16(_fbdata_start)
|
ldui r9, #%hi16(_fbdata_start)
|
ori r9, r9, #%lo16(_fbdata_start)
|
ori r9, r9, #%lo16(_fbdata_start)
|
ldui r10, #%hi16(_fbdata_end)
|
ldui r10, #%hi16(_fbdata_end)
|
ori r10, r10, #%lo16(_fbdata_end)
|
ori r10, r10, #%lo16(_fbdata_end)
|
ldui r11, #%hi16(__FRAME_BUFFER_START)
|
ldui r11, #%hi16(__FRAME_BUFFER_START)
|
brle r10, r9, .Lnext1
|
brle r10, r9, .Lnext1
|
ori r11, r11, #%lo16(__FRAME_BUFFER_START)
|
ori r11, r11, #%lo16(__FRAME_BUFFER_START)
|
.Lcpy0:
|
.Lcpy0:
|
ldw r5, r9, #$0
|
ldw r5, r9, #$0
|
addi r9, r9, #$4
|
addi r9, r9, #$4
|
stw r5, r11, #$0
|
stw r5, r11, #$0
|
brlt r9, r10, .Lcpy0
|
brlt r9, r10, .Lcpy0
|
addi r11, r11, #$4
|
addi r11, r11, #$4
|
|
|
.Lnext1:
|
.Lnext1:
|
;; Copy data from ROM to External Memory (off-chip memory)
|
;; Copy data from ROM to External Memory (off-chip memory)
|
ldui r9, #%hi16(_extdata_start)
|
ldui r9, #%hi16(_extdata_start)
|
ori r9, r9, #%lo16(_extdata_start)
|
ori r9, r9, #%lo16(_extdata_start)
|
ldui r10, #%hi16(_extdata_end)
|
ldui r10, #%hi16(_extdata_end)
|
ori r10, r10, #%lo16(_extdata_end)
|
ori r10, r10, #%lo16(_extdata_end)
|
ldui r11, #%hi16(__EXTERNAL_MEMORY_START)
|
ldui r11, #%hi16(__EXTERNAL_MEMORY_START)
|
brle r10, r9, .Lnext2
|
brle r10, r9, .Lnext2
|
ori r11, r11, #%lo16(__EXTERNAL_MEMORY_START)
|
ori r11, r11, #%lo16(__EXTERNAL_MEMORY_START)
|
.Lcpy1:
|
.Lcpy1:
|
ldw r5, r9, #$0
|
ldw r5, r9, #$0
|
addi r9, r9, #$4
|
addi r9, r9, #$4
|
stw r5, r11, #$0
|
stw r5, r11, #$0
|
brlt r9, r10, .Lcpy1
|
brlt r9, r10, .Lcpy1
|
addi r11, r11, #$4
|
addi r11, r11, #$4
|
|
|
|
|
.Lnext2:
|
.Lnext2:
|
;; Zero the bss space
|
;; Zero the bss space
|
ldui r9, #%hi16(__bss_start)
|
ldui r9, #%hi16(__bss_start)
|
addui r9, r9, #%lo16(__bss_start)
|
addui r9, r9, #%lo16(__bss_start)
|
ldui r10, #%hi16(__bss_end)
|
ldui r10, #%hi16(__bss_end)
|
addui r10, r10, #%lo16(__bss_end)
|
addui r10, r10, #%lo16(__bss_end)
|
or r0, r0, r0
|
or r0, r0, r0
|
brle r10, r9, .Lnext3
|
brle r10, r9, .Lnext3
|
or r0, r0, r0
|
or r0, r0, r0
|
.Lcpy2:
|
.Lcpy2:
|
stw r0, r9, #0
|
stw r0, r9, #0
|
addi r9, r9, #4
|
addi r9, r9, #4
|
or r0, r0, r0 ; nop
|
or r0, r0, r0 ; nop
|
brle r9, r10, .Lcpy2
|
brle r9, r10, .Lcpy2
|
or r0, r0, r0 ; nop
|
or r0, r0, r0 ; nop
|
|
|
.Lnext3:
|
.Lnext3:
|
;; Zero the external memory bss section
|
;; Zero the external memory bss section
|
ldui r9, #%hi16(_extbss_start)
|
ldui r9, #%hi16(_extbss_start)
|
ori r9, r9, #%lo16(_extbss_start)
|
ori r9, r9, #%lo16(_extbss_start)
|
ldui r10, #%hi16(_extbss_end)
|
ldui r10, #%hi16(_extbss_end)
|
ori r10, r10, #%lo16(_extbss_end)
|
ori r10, r10, #%lo16(_extbss_end)
|
or r0, r0, r0
|
or r0, r0, r0
|
brle r10, r9, .Lnext4
|
brle r10, r9, .Lnext4
|
or r0, r0, r0
|
or r0, r0, r0
|
.Lcpy3:
|
.Lcpy3:
|
stw r0, r9, #$0
|
stw r0, r9, #$0
|
addi r9, r9, #$4
|
addi r9, r9, #$4
|
or r0, r0, r0
|
or r0, r0, r0
|
brle r9, r10, .Lcpy3
|
brle r9, r10, .Lcpy3
|
or r0, r0, r0
|
or r0, r0, r0
|
|
|
.Lnext4:
|
.Lnext4:
|
;; Call global and static constructors
|
;; Call global and static constructors
|
ldui r10, #%hi16(_init)
|
ldui r10, #%hi16(_init)
|
ori r10, r10, #%lo16(_init)
|
ori r10, r10, #%lo16(_init)
|
or r0, r0, r0 ; nop
|
or r0, r0, r0 ; nop
|
jal r14, r10
|
jal r14, r10
|
or r0, r0, r0 ; nop
|
or r0, r0, r0 ; nop
|
|
|
;; Setup destructors to be called from exit.
|
;; Setup destructors to be called from exit.
|
;; (Just in case main never returns....)
|
;; (Just in case main never returns....)
|
ldui r10, #%hi16(atexit)
|
ldui r10, #%hi16(atexit)
|
ori r10, r10, #%lo16(atexit)
|
ori r10, r10, #%lo16(atexit)
|
ldui r1, #%hi16(_fini)
|
ldui r1, #%hi16(_fini)
|
ori r1, r1, #%lo16(_fini)
|
ori r1, r1, #%lo16(_fini)
|
or r0, r0, r0 ; nop
|
or r0, r0, r0 ; nop
|
jal r14, r10
|
jal r14, r10
|
or r0, r0, r0 ; nop
|
or r0, r0, r0 ; nop
|
|
|
;; Initialise argc, argv and envp to empty
|
;; Initialise argc, argv and envp to empty
|
addi r1, r0, #0
|
addi r1, r0, #0
|
addi r2, r0, #0
|
addi r2, r0, #0
|
addi r3, r0, #0
|
addi r3, r0, #0
|
|
|
;; Call main
|
;; Call main
|
ldui r10, #%hi16(main)
|
ldui r10, #%hi16(main)
|
ori r10, r10, #%lo16(main)
|
ori r10, r10, #%lo16(main)
|
or r0, r0, r0 ; nop
|
or r0, r0, r0 ; nop
|
jal r14, r10
|
jal r14, r10
|
or r0, r0, r0 ; nop
|
or r0, r0, r0 ; nop
|
|
|
;; DJK - Added 12Nov01. Pass main's return value to exit.
|
;; DJK - Added 12Nov01. Pass main's return value to exit.
|
or r1, r11, r0
|
or r1, r11, r0
|
|
|
;; Jump to exit
|
;; Jump to exit
|
ldui r10, #%hi16(exit)
|
ldui r10, #%hi16(exit)
|
ori r10, r10, #%lo16(exit)
|
ori r10, r10, #%lo16(exit)
|
or r0, r0, r0 ; nop
|
or r0, r0, r0 ; nop
|
jal r14, r10
|
jal r14, r10
|
or r0, r0, r0 ; nop
|
or r0, r0, r0 ; nop
|
|
|
;; Exit does not return, however, this code is to catch an
|
;; Exit does not return, however, this code is to catch an
|
;; error if it does. Set the processor into sleep mode.
|
;; error if it does. Set the processor into sleep mode.
|
ori r1, r0, #$1
|
ori r1, r0, #$1
|
stw r1, r0, #HALT_REG
|
stw r1, r0, #HALT_REG
|
or r0, r0, r0
|
or r0, r0, r0
|
or r0, r0, r0
|
or r0, r0, r0
|
or r0, r0, r0
|
or r0, r0, r0
|
or r0, r0, r0
|
or r0, r0, r0
|
or r0, r0, r0
|
or r0, r0, r0
|
.Lend:
|
.Lend:
|
jmp .Lend
|
jmp .Lend
|
or r0, r0, r0
|
or r0, r0, r0
|
|
|
