mirror of
https://github.com/wiiu-env/libfat.git
synced 2024-11-25 19:36:52 +01:00
129 lines
3.9 KiB
ArmAsm
129 lines
3.9 KiB
ArmAsm
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
|
|
@ io_scsd_s.s
|
|
@
|
|
@ Hardware Routines for reading a Secure Digital card
|
|
@ using the SC SD
|
|
@
|
|
@ Based on code supplied by Romman
|
|
@
|
|
@ Copyright (c) 2006 Michael "Chishm" Chisholm
|
|
@
|
|
@ Redistribution and use in source and binary forms, with or without modification,
|
|
@ are permitted provided that the following conditions are met:
|
|
@
|
|
@ 1. Redistributions of source code must retain the above copyright notice,
|
|
@ this list of conditions and the following disclaimer.
|
|
@ 2. Redistributions in binary form must reproduce the above copyright notice,
|
|
@ this list of conditions and the following disclaimer in the documentation and/or
|
|
@ other materials provided with the distribution.
|
|
@ 3. The name of the author may not be used to endorse or promote products derived
|
|
@ from this software without specific prior written permission.
|
|
@
|
|
@ THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
|
@ WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
|
|
@ AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
|
|
@ LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
@ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
@ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
@ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
@ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
|
|
@ EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
@
|
|
@ 2006-07-22 - Chishm
|
|
@ * First release of stable code
|
|
@
|
|
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
|
|
|
|
.align 4
|
|
.arm
|
|
|
|
.equ REG_SCSD_DATAWRITE, 0x09000000
|
|
.equ BYTES_PER_READ, 0x200
|
|
.equ SCSD_STS_BUSY, 0x100
|
|
.equ BUSY_WAIT_TIMEOUT, 0x10000
|
|
.equ FALSE, 0
|
|
.equ TRUE, 1
|
|
|
|
@ bool _SCSD_writeData_s (u8 *data, u16* crc)
|
|
|
|
.global _SCSD_writeData_s
|
|
|
|
_SCSD_writeData_s:
|
|
stmfd r13!, {r4-r5}
|
|
mov r5, #BYTES_PER_READ
|
|
mov r2, #REG_SCSD_DATAWRITE
|
|
|
|
@ Wait for a free data buffer on the SD card
|
|
mov r4, #BUSY_WAIT_TIMEOUT
|
|
_SCSD_writeData_busy_wait:
|
|
@ Test for timeout
|
|
subs r4, r4, #1
|
|
moveq r0, #FALSE @ return false on failure
|
|
beq _SCSD_writeData_return
|
|
@ Check the busy bit of the status register
|
|
ldrh r3, [r2]
|
|
tst r3, #SCSD_STS_BUSY
|
|
beq _SCSD_writeData_busy_wait
|
|
|
|
ldrh r3, [r2] @ extra clock
|
|
|
|
mov r3, #0 @ start bit
|
|
strh r3,[r2]
|
|
|
|
@ Check if the data buffer is aligned on a halfword boundary
|
|
tst r0, #1
|
|
beq _SCSD_writeData_data_loop
|
|
|
|
@ Used when the source data is unaligned
|
|
_SCSD_writeData_data_loop_unaligned:
|
|
ldrb r3, [r0], #1
|
|
ldrb r4, [r0], #1
|
|
orr r3, r3, r4, lsl #8
|
|
stmia r2, {r3-r4}
|
|
subs r5, r5, #2
|
|
bne _SCSD_writeData_data_loop_unaligned
|
|
b _SCSD_writeData_crc
|
|
|
|
@ Write the data to the card
|
|
@ 4 halfwords are transmitted to the Supercard at once, for timing purposes
|
|
@ Only the first halfword needs to contain data
|
|
_SCSD_writeData_data_loop:
|
|
ldrh r3, [r0], #2
|
|
stmia r2, {r3-r4}
|
|
subs r5, r5, #2
|
|
bne _SCSD_writeData_data_loop
|
|
|
|
@ Send the data CRC
|
|
_SCSD_writeData_crc:
|
|
cmp r1, #0
|
|
movne r0, r1
|
|
movne r1, #0
|
|
movne r5, #8
|
|
bne _SCSD_writeData_data_loop
|
|
|
|
mov r3, #0xff @ end bit
|
|
strh r3, [r2]
|
|
|
|
@ Wait for the SD card to signal that it is finished recieving
|
|
mov r4, #BUSY_WAIT_TIMEOUT
|
|
_SCSD_writeData_finished_wait:
|
|
@ Test for timeout
|
|
subs r4, r4, #1
|
|
moveq r0, #FALSE @ return false on failure
|
|
beq _SCSD_writeData_return
|
|
@ Check the busy bit of the status register
|
|
ldrh r3, [r2]
|
|
tst r3, #0x100
|
|
bne _SCSD_writeData_finished_wait
|
|
|
|
@ Send 8 more clocks, as required by the SD card
|
|
ldmia r2, {r3-r4}
|
|
|
|
@ return true for success
|
|
mov r0, #TRUE
|
|
|
|
_SCSD_writeData_return:
|
|
ldmfd r13!,{r4-r5}
|
|
bx r14
|
|
|