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/*
* Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 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.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER OR CONTRIBUTORS 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.
*/
#include <arch.h>
#include <asm_macros.S>
#include <pl011.h>
.globl console_init
.globl console_putc
.globl console_flush
.globl console_core_init
.globl console_core_putc
.globl console_core_flush
.globl console_getc
/*
* The console base is in the data section and not in .bss
* even though it is zero-init. In particular, this allows
* the console functions to start using this variable before
* the runtime memory is initialized for images which do not
* need to copy the .data section from ROM to RAM.
*/
.section .data.console_base ; .align 2
console_base: .word 0x0
/* -----------------------------------------------
* int console_init(uintptr_t base_addr,
* unsigned int uart_clk, unsigned int baud_rate)
* Function to initialize the console without a
* C Runtime to print debug information. It saves
* the console base to the data section.
* In: r0 - console base address
* r1 - Uart clock in Hz
* r2 - Baud rate
* out: return 1 on success else 0 on error
* Clobber list : r1 - r3
* -----------------------------------------------
*/
func console_init
ldr r3, =console_base
str r0, [r3]
b console_core_init
endfunc console_init
/* -----------------------------------------------
* int console_core_init(uintptr_t base_addr,
* unsigned int uart_clk, unsigned int baud_rate)
* Function to initialize the console without a
* C Runtime to print debug information. This
* function will be accessed by console_init and
* crash reporting.
* In: r0 - console base address
* r1 - Uart clock in Hz
* r2 - Baud rate
* Out: return 1 on success else 0 on error
* Clobber list : r1, r2, r3
* -----------------------------------------------
*/
func console_core_init
/* Check the input base address */
cmp r0, #0
beq core_init_fail
/* Check baud rate and uart clock for sanity */
cmp r1, #0
beq core_init_fail
cmp r2, #0
beq core_init_fail
/* Disable the UART before initialization */
ldr r3, [r0, #UARTCR]
bic r3, r3, #PL011_UARTCR_UARTEN
str r3, [r0, #UARTCR]
/* Program the baudrate */
/* Divisor = (Uart clock * 4) / baudrate */
lsl r1, r1, #2
udiv r2, r1, r2
/* IBRD = Divisor >> 6 */
lsr r1, r2, #6
/* Write the IBRD */
str r1, [r0, #UARTIBRD]
/* FBRD = Divisor & 0x3F */
and r1, r2, #0x3f
/* Write the FBRD */
str r1, [r0, #UARTFBRD]
mov r1, #PL011_LINE_CONTROL
str r1, [r0, #UARTLCR_H]
/* Clear any pending errors */
mov r1, #0
str r1, [r0, #UARTECR]
/* Enable tx, rx, and uart overall */
ldr r1, =(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN)
str r1, [r0, #UARTCR]
mov r0, #1
bx lr
core_init_fail:
mov r0, #0
bx lr
endfunc console_core_init
/* ---------------------------------------------
* int console_putc(int c)
* Function to output a character over the
* console. It returns the character printed on
* success or -1 on error.
* In : r0 - character to be printed
* Out : return -1 on error else return character.
* Clobber list : r1, r2
* ---------------------------------------------
*/
func console_putc
ldr r2, =console_base
ldr r1, [r2]
b console_core_putc
endfunc console_putc
/* --------------------------------------------------------
* int console_core_putc(int c, uintptr_t base_addr)
* Function to output a character over the console. It
* returns the character printed on success or -1 on error.
* In : r0 - character to be printed
* r1 - console base address
* Out : return -1 on error else return character.
* Clobber list : r2
* --------------------------------------------------------
*/
func console_core_putc
/* Check the input parameter */
cmp r1, #0
beq putc_error
/* Prepend '\r' to '\n' */
cmp r0, #0xA
bne 2f
1:
/* Check if the transmit FIFO is full */
ldr r2, [r1, #UARTFR]
tst r2, #PL011_UARTFR_TXFF_BIT
beq 1b
mov r2, #0xD
str r2, [r1, #UARTDR]
2:
/* Check if the transmit FIFO is full */
ldr r2, [r1, #UARTFR]
tst r2, #PL011_UARTFR_TXFF_BIT
beq 2b
str r0, [r1, #UARTDR]
bx lr
putc_error:
mov r0, #-1
bx lr
endfunc console_core_putc
/* ---------------------------------------------
* int console_getc(void)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 on error.
* Clobber list : r0, r1
* ---------------------------------------------
*/
func console_getc
ldr r1, =console_base
ldr r0, [r1]
cmp r0, #0
beq getc_error
1:
/* Check if the receive FIFO is empty */
ldr r1, [r0, #UARTFR]
tst r1, #PL011_UARTFR_RXFE_BIT
beq 1b
ldr r1, [r0, #UARTDR]
mov r0, r1
bx lr
getc_error:
mov r0, #-1
bx lr
endfunc console_getc
/* ---------------------------------------------
* int console_flush(void)
* Function to force a write of all buffered
* data that hasn't been output. It returns 0
* upon successful completion, otherwise it
* returns -1.
* Clobber list : r0, r1
* ---------------------------------------------
*/
func console_flush
ldr r1, =console_base
ldr r0, [r1]
b console_core_flush
endfunc console_flush
/* ---------------------------------------------
* int console_core_flush(uintptr_t base_addr)
* Function to force a write of all buffered
* data that hasn't been output.
* In : r0 - console base address
* Out : return -1 on error else return 0.
* Clobber list : r0, r1
* ---------------------------------------------
*/
func console_core_flush
cmp r0, #0
beq flush_error
1:
/* Loop while the transmit FIFO is busy */
ldr r1, [r0, #UARTFR]
tst r1, #PL011_UARTFR_BUSY
bne 1b
mov r0, #0
bx lr
flush_error:
mov r0, #-1
bx lr
endfunc console_core_flush
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