isfshax/stage2/lolserial_asm.S

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2021-05-26 01:53:11 +02:00
/*
* minute - a port of the "mini" IOS replacement for the Wii U.
*
* Copyright (C) 2021 Roberto Van Eeden <rwrr0644@gmail.com>
*
* This code is licensed to you under the terms of the GNU GPL, version 2;
* see file COPYING or http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
*/
#ifdef LOLSERIAL_DEBUG
#include "latte.h"
.arm
.globl lolserial_print
.globl lolserial_lprint
.section .text
/*
* the number of timer ticks to wait
* each bit; might need manual adjustment
* for particoular serial adapters, usually
* the stable value is in the +5/-5 range
*/
.equ LOLSERIAL_WAIT_TICKS, 200
.equ GP_SENSORBAR, 0x00000100
.equ GP_SENSORBAR_SHIFT, 8
lolserial_print:
mov r1, #-1
lolserial_lprint:
push {r5-r6}
add r1, r1, r0
ldr r6, =0x0D800000
/* clear32(LT_GPIO_OWNER, GP_SENSORBAR) */
ldr r5, [r6, #0x0FC]
bic r5, r5, #GP_SENSORBAR
str r5, [r6, #0x0FC]
/* set32(LT_GPIO_ENABLE, GP_SENSORBAR) */
ldr r5, [r6, #0x0DC]
orr r5, r5, #GP_SENSORBAR
str r5, [r6, #0x0DC]
/* set32(LT_GPIO_DIR, GP_SENSORBAR) */
ldr r5, [r6, #0x0E4]
orr r5, r5, #GP_SENSORBAR
str r5, [r6, #0x0E4]
/* set32(LT_GPIO_OUT, GP_SENSORBAR) */
ldr r5, [r6, #0x0E0]
orr r5, r5, #GP_SENSORBAR
str r5, [r6, #0x0E0]
lolserial_send_string_loop:
cmp r0, r1
ldrneb r5, [r0], #1
cmpne r5, #0
beq lolserial_send_string_end
mov r3, #0x200
orr r3, r3, r5, lsl #1
lolserial_send_char_loop:
and r4, r3, #1
ldr r5, [r6, #0x0E0]
bic r5, r5, #GP_SENSORBAR
orr r5, r5, r4, lsl #GP_SENSORBAR_SHIFT
str r5, [r6, #0x0E0]
ldr r5, [r6, #0x010]
adds r4, r5, #LOLSERIAL_WAIT_TICKS
bcc timer_wait_loop
timer_wait_overflow_loop:
ldr r2, [r6, #0x010]
cmp r2, r5
bhs timer_wait_overflow_loop
timer_wait_loop:
ldr r5, [r6, #0x010]
cmp r5, r4
blo timer_wait_loop
movs r3, r3, lsr #1
bne lolserial_send_char_loop
b lolserial_send_string_loop
lolserial_send_string_end:
pop {r5-r6}
bx lr
#endif /* LOLSERIAL_DEBUG */