Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  linux/arch/arm/lib/clear_user.S

 *

 *  Copyright (C) 1995, 1996,1997,1998 Russell King

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#include 

#include 

                .text

/* Prototype: int __clear_user(void *addr, size_t sz)

 * Purpose  : clear some user memory

 * Params   : addr - user memory address to clear

 *          : sz   - number of bytes to clear

 * Returns  : number of bytes NOT cleared

 */

ENTRY(__clear_user)

                stmfd   sp!, {r1, lr}

                mov     r2, #0

                cmp     r1, #4

                blt     2f

                ands    ip, r0, #3

                beq     1f

                cmp     ip, #2

USER(           strbt   r2, [r0], #1)

USER(           strlebt r2, [r0], #1)

USER(           strltbt r2, [r0], #1)

                rsb     ip, ip, #4

                sub     r1, r1, ip              @  7  6  5  4  3  2  1

1:              subs    r1, r1, #8              @ -1 -2 -3 -4 -5 -6 -7

USER(           strplt  r2, [r0], #4)

USER(           strplt  r2, [r0], #4)

                bpl     1b

                adds    r1, r1, #4              @  3  2  1  0 -1 -2 -3

USER(           strplt  r2, [r0], #4)

2:              tst     r1, #2                  @ 1x 1x 0x 0x 1x 1x 0x

USER(           strnebt r2, [r0], #1)

USER(           strnebt r2, [r0], #1)

                tst     r1, #1                  @ x1 x0 x1 x0 x1 x0 x1

USER(           strnebt r2, [r0], #1)

                mov     r0, #0

                ldmfd   sp!, {r1, pc}

                .section .fixup,"ax"

                .align  0

9001:           ldmfd   sp!, {r0, pc}

                .previous