From mboxrd@z Thu Jan  1 00:00:00 1970
From: YanMin Qiao <sepherosa@sohu.com>
Date: Sat, 04 Jan 2003 00:22:21 +0800
Subject: [U-Boot-Users] relocate_code
Message-ID: <3E15B8BD.1030009@sohu.com>
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<u-boot>/cpu/mpc8xx/start.S

....
....
    .globl    relocate_code
relocate_code:
    mr    r1,  r3        /* Set new stack pointer        */
    mr    r9,  r4        /* Save copy of Global Data pointer    */
    mr    r10, r5        /* Save copy of Destination Address    */
....
    cmplw    cr1,r3,r4
    addi    r0,r5,3
    srwi.    r0,r0,2
    beq    cr1,4f        /* In place copy is not necessary    */
    beq    7f        /* Protect against 0 count        */
    mtctr    r0
    bge    cr1,2f
    ^^^^^^^^^^ why we need to differeciate the two situation, 
addr>CFG_MONITOR_BASE
                         and addr<=CFG_MONITOR_BASE

    la    r8,-4(r4)
    la    r7,-4(r3)
1:    lwzu    r0,4(r8)
    stwu    r0,4(r7)
    bdnz    1b
    b    4f

2:    slwi    r0,r0,2        <<----------------- i think above code will 
be enough for the two        
    add    r8,r4,r0                                      situation
    add    r7,r3,r0
3:    lwzu    r0,-4(r8)
    stwu    r0,-4(r7)
    bdnz    3b
....
....


thnx
best regards