107 lines
2.9 KiB
ArmAsm
107 lines
2.9 KiB
ArmAsm
/*
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* Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#include <asm_macros.S>
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.globl console_init
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.globl console_uninit
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.globl console_putc
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.globl console_getc
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.globl console_flush
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/*
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* The console base is in the data section and not in .bss
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* even though it is zero-init. In particular, this allows
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* the console functions to start using this variable before
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* the runtime memory is initialized for images which do not
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* need to copy the .data section from ROM to RAM.
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*/
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.section .data.console_base ; .align 2
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console_base: .word 0x0
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/* -----------------------------------------------
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* int console_init(uintptr_t base_addr,
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* unsigned int uart_clk, unsigned int baud_rate)
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* Function to initialize the console without a
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* C Runtime to print debug information. It saves
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* the console base to the data section.
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* In: r0 - console base address
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* r1 - Uart clock in Hz
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* r2 - Baud rate
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* out: return 1 on success else 0 on error
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* Clobber list : r1 - r3
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* -----------------------------------------------
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*/
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func console_init
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/* Check the input base address */
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cmp r0, #0
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beq init_fail
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ldr r3, =console_base
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str r0, [r3]
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b console_core_init
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init_fail:
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bx lr
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endfunc console_init
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/* -----------------------------------------------
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* void console_uninit(void)
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* Function to finish the use of console driver.
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* It sets the console_base as NULL so that any
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* further invocation of `console_putc` or
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* `console_getc` APIs would return error.
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* -----------------------------------------------
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*/
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func console_uninit
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mov r0, #0
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ldr r3, =console_base
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str r0, [r3]
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bx lr
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endfunc console_uninit
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/* ---------------------------------------------
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* int console_putc(int c)
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* Function to output a character over the
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* console. It returns the character printed on
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* success or -1 on error.
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* In : r0 - character to be printed
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* Out : return -1 on error else return character.
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* Clobber list : r1, r2
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* ---------------------------------------------
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*/
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func console_putc
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ldr r2, =console_base
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ldr r1, [r2]
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b console_core_putc
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endfunc console_putc
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/* ---------------------------------------------
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* int console_getc(void)
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* Function to get a character from the console.
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* It returns the character grabbed on success
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* or -1 on error.
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* Clobber list : r0, r1
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* ---------------------------------------------
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*/
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func console_getc
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ldr r1, =console_base
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ldr r0, [r1]
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b console_core_getc
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endfunc console_getc
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/* ---------------------------------------------
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* int console_flush(void)
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* Function to force a write of all buffered
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* data that hasn't been output. It returns 0
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* upon successful completion, otherwise it
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* returns -1.
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* Clobber list : r0, r1
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* ---------------------------------------------
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*/
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func console_flush
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ldr r1, =console_base
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ldr r0, [r1]
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b console_core_flush
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endfunc console_flush
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