rockbox/rbutil/mkimxboot/dualboot/dualboot.S
Amaury Pouly 15c69b8baf mkximxboot/fuze+: add power button delay to power on
Only boot to rockbox if the power button is hold sufficiently long.
For consistency, use the same mechanism as the OF:
- read PSWITCH 550000 times
- boot if PSWITCH=1 at least 400000 out of 550000 times
Only apply the delay if Volume Down is not hold,
so that the OF and RB delay don't cumulate.

Change-Id: I1e8a4cd108c56bf784fcf1c320f7a001ef161701
2012-02-28 00:03:46 +01:00

61 lines
2.2 KiB
ArmAsm

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2011 by Amaury Pouly
*
* 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.
*
****************************************************************************/
.text
.global start
@ int start(uint32_t arg, uint32_t *result_id)
start:
stmfd sp!, {r4-r6,lr}
#if defined(SANSA_FUZEPLUS)
/* If volume down key is hold, return so that the OF can boot */
ldr r2, =0x80018610 @ HW_PINCTRL_DIN1
ldr r2, [r2]
tst r2, #0x40000000 @ bit 30, active low
moveq r0, #0 @ return 0, continue boot
bxeq lr
/* otherwise monitor the power button for a short time */
ldr r2, =550000 @ loop count
ldr r4, =0 @ number of times PSWITCH was 1
pswitch_monitor_loop:
ldr r3, =0x800440c0 @ HW_POWER_STS
ldr r3, [r3]
mov r3, r3, lsl#10
mov r3, r3, lsr#30 @ extract PSWITCH
cmp r3, #1
addeq r4, r3 @ add one if PSWITCH=1 (means power hold)
subs r2, #1
bne pswitch_monitor_loop
/* power down if power wasn't hold long enough */
ldr r2, =400000
cmp r4, r2
bcc power_down
/* jump to section given as argument */
str r0, [r1]
mov r0, #1
ldmfd sp!, {r4-r6,pc}
power_down:
ldr r0, =0x80044100 @ HW_POWER_RESET
ldr r1, =0x3E770001 @ unlock key + power down
str r1, [r0]
b power_down
#else
#error No target defined !
#endif