rockbox/firmware/target/arm/bits-armv4.S

/***************************************************************************
*             __________               __   ___.
*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
*                     \/            \/     \/    \/            \/
* $Id$
*
* Copyright (C) 2010 by Michael Sevakis
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/

/***************************************************************************
 * uint32_t bitmod32(volatile uint32_t *addr, uint32_t bits, uint32_t mask)
 */
    .section    .text.bitmod32, "ax", %progbits
    .align      2
    .global     bitmod32
    .type       bitmod32, %function
bitmod32:
    mrs    r12, cpsr
    orr    r3, r12, #0xc0
    msr    cpsr_c, r3
    mov    r3, r0
    ldr    r0, [r3]
    and    r1, r1, r2               @ Only allow mod of bits in 'mask'
    bic    r2, r0, r2               @ Clear mask bits
    orr    r1, r2, r1               @ Set according to 'bits'
    str    r1, [r3]
    msr    cpsr_c, r12
    bx     lr
    .size  bitmod32, .-bitmod32


/***************************************************************************
 * uint32_t bitset32(volatile uint32_t *addr, uint32_t mask)
 */
    .section    .text.bitset32, "ax", %progbits
    .align      2
    .global     bitset32
    .type       bitset32, %function
bitset32:
    mov    r2, r0
    mrs    r12, cpsr
    orr    r3, r12, #0xc0
    msr    cpsr_c, r3
    ldr    r0, [r2]
    orr    r1, r0, r1
    str    r1, [r2]
    msr    cpsr_c, r12
    bx     lr
    .size  bitset32, .-bitset32


/***************************************************************************
 * uint32_t bitclr32(volatile uint32_t *addr, uint32_t mask)
 */
     .section    .text.bitclr32, "ax", %progbits
     .align      2
     .global     bitclr32
     .type       bitclr32, %function
bitclr32:
    mov    r2, r0
    mrs    r12, cpsr
    orr    r3, r12, #0xc0
    msr    cpsr_c, r3
    ldr    r0, [r2]
    bic    r1, r0, r1
    str    r1, [r2]
    msr    cpsr_c, r12
    bx     lr
    .size  bitclr32, .-bitclr32


/***************************************************************************
 * uint16_t bitmod16(volatile uint16_t *addr, uint16_t bits, uint16_t mask)
 */
    .section    .text.bitmod16, "ax", %progbits
    .align      2
    .global     bitmod16
    .type       bitmod16, %function
bitmod16:
    mrs    r12, cpsr
    orr    r3, r12, #0xc0
    msr    cpsr_c, r3
    mov    r3, r0
    ldrh   r0, [r3]
    and    r1, r1, r2               @ Only allow mod of bits in 'mask'
    bic    r2, r0, r2               @ Clear mask bits
    orr    r1, r2, r1               @ Set according to 'bits'
    strh   r1, [r3]
    msr    cpsr_c, r12
    bx     lr
    .size  bitmod16, .-bitmod16


/***************************************************************************
 * uint16_t bitset16(volatile uint16_t *addr, uint16_t mask)
 */
    .section    .text.bitset16, "ax", %progbits
    .align      2
    .global     bitset16
    .type       bitset16, %function
bitset16:
    mov    r2, r0
    mrs    r12, cpsr
    orr    r3, r12, #0xc0
    msr    cpsr_c, r3
    ldrh   r0, [r2]
    orr    r1, r0, r1
    strh   r1, [r2]
    msr    cpsr_c, r12
    bx     lr
    .size  bitset16, .-bitset16


/***************************************************************************
 * uint16_t bitclr16(volatile uint16_t *addr, uint16_t mask)
 */
     .section    .text.bitclr16, "ax", %progbits
     .align      2
     .global     bitclr16
     .type       bitclr16, %function
bitclr16:
    mov    r2, r0
    mrs    r12, cpsr
    orr    r3, r12, #0xc0
    msr    cpsr_c, r3
    ldrh   r0, [r2]
    bic    r1, r0, r1
    strh   r1, [r2]
    msr    cpsr_c, r12
    bx     lr
    .size  bitclr16, .-bitclr16