source: rtems/c/src/lib/libbsp/m32r/m32rsim/start/start.S @ 9b4422a2

/*
 *  From Newlib 1.16.0
 */

        .text
        .balign 4
        .global _start
_start:

        seth    sp, #shigh(_stack)
        add3    sp, sp, #low(_stack)
        ldi     fp, #0

# Clear the BSS.  Do it in two parts for efficiency: longwords first
# for most of it, then the remaining 0 to 3 bytes.

        seth    r2, #shigh(__bss_start)
        add3    r2, r2, #low(__bss_start); R2 = start of BSS
        seth    r3, #shigh(_end)
        add3    r3, r3, #low(_end)      ; R3 = end of BSS + 1

        sub     r3, r2          ; R3 = BSS size in bytes
        mv      r4, r3
        srli    r4, #2          ; R4 = BSS size in longwords (rounded down)
        ldi     r1, #0          ; clear R1 for longword store
        addi    r2, #-4         ; account for pre-inc store
        beqz    r4, .Lendloop1  ; any more to go?
.Lloop1:
        st      r1, @+r2        ; yep, zero out another longword
        addi    r4, #-1         ; decrement count
        bnez    r4, .Lloop1     ; go do some more
.Lendloop1:
        and3    r4, r3, #3      ; get no. of remaining BSS bytes to clear
        addi    r2, #4          ; account for pre-inc store
        beqz    r4, .Lendloop2  ; any more to go?
.Lloop2:
        stb     r1, @r2         ; yep, zero out another byte
        addi    r2, #1          ; bump address
        addi    r4, #-1         ; decrement count
        bnez    r4, .Lloop2     ; go do some more
.Lendloop2:

# Run code in the .init section.
# This will queue the .fini section to be run with atexit.

        # bl    __init

# Call main, then exit.

        ldi     r1, #0           ; r1 = argv
        ldi     r0, #0           ; r0 = argc
        bl      boot_card

# If that fails just loop.

.Lexit:
        bra     .Lexit