/* * Copyright (c) 2016-2020, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include #include #include #include #include /* * "core" functions are low-level implementations that don't require * writable memory and are thus safe to call in BL1 crash context. */ .globl console_cdns_core_init .globl console_cdns_core_putc .globl console_cdns_core_getc .globl console_cdns_core_flush .globl console_cdns_putc .globl console_cdns_getc .globl console_cdns_flush /* ----------------------------------------------- * int console_cdns_core_init(uintptr_t base_addr) * Function to initialize the console without a * C Runtime to print debug information. This * function will be accessed by console_init and * crash reporting. * We assume that the bootloader already set up * the HW (baud, ...) and only enable the trans- * mitter and receiver here. * In: x0 - console base address * Out: return 1 on success else 0 on error * Clobber list : x1, x2, x3 * ----------------------------------------------- */ func console_cdns_core_init /* Check the input base address */ cbz x0, core_init_fail /* RX/TX enabled & reset */ mov w3, #(R_UART_CR_TX_EN | R_UART_CR_RX_EN | R_UART_CR_TXRST | R_UART_CR_RXRST) str w3, [x0, #R_UART_CR] mov w0, #1 ret core_init_fail: mov w0, wzr ret endfunc console_cdns_core_init .globl console_cdns_register /* ----------------------------------------------- * int console_cdns_register(uintptr_t baseaddr, * uint32_t clock, uint32_t baud, * console_t *console); * Function to initialize and register a new CDNS * console. Storage passed in for the console struct * *must* be persistent (i.e. not from the stack). * In: x0 - UART register base address * w1 - UART clock in Hz * w2 - Baud rate * x3 - pointer to empty console_t struct * Out: return 1 on success, 0 on error * Clobber list : x0, x1, x2, x6, x7, x14 * ----------------------------------------------- */ func console_cdns_register mov x7, x30 mov x6, x3 cbz x6, register_fail str x0, [x6, #CONSOLE_T_BASE] bl console_cdns_core_init cbz x0, register_fail mov x0, x6 mov x30, x7 finish_console_register cdns putc=1, getc=ENABLE_CONSOLE_GETC, flush=1 register_fail: ret x7 endfunc console_cdns_register /* -------------------------------------------------------- * int console_cdns_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 : w0 - character to be printed * x1 - console base address * Out : return -1 on error else return character. * Clobber list : x2 * -------------------------------------------------------- */ func console_cdns_core_putc #if ENABLE_ASSERTIONS cmp x1, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ /* Prepend '\r' to '\n' */ cmp w0, #0xA b.ne 2f 1: /* Check if the transmit FIFO is empty */ ldr w2, [x1, #R_UART_SR] tbz w2, #UART_SR_INTR_TEMPTY_BIT, 1b mov w2, #0xD str w2, [x1, #R_UART_TX] 2: /* Check if the transmit FIFO is empty */ ldr w2, [x1, #R_UART_SR] tbz w2, #UART_SR_INTR_TEMPTY_BIT, 2b str w0, [x1, #R_UART_TX] ret endfunc console_cdns_core_putc /* -------------------------------------------------------- * int console_cdns_putc(int c, console_t *cdns) * Function to output a character over the console. It * returns the character printed on success or -1 on error. * In : w0 - character to be printed * x1 - pointer to console_t structure * Out : return -1 on error else return character. * Clobber list : x2 * -------------------------------------------------------- */ func console_cdns_putc #if ENABLE_ASSERTIONS cmp x1, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ ldr x1, [x1, #CONSOLE_T_BASE] b console_cdns_core_putc endfunc console_cdns_putc /* --------------------------------------------- * int console_cdns_core_getc(uintptr_t base_addr) * Function to get a character from the console. * It returns the character grabbed on success * or -1 if no character is available. * In : x0 - console base address * Out: w0 - character if available, else -1 * Clobber list : x0, x1 * --------------------------------------------- */ func console_cdns_core_getc #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ /* Check if the receive FIFO is empty */ ldr w1, [x0, #R_UART_SR] tbnz w1, #UART_SR_INTR_REMPTY_BIT, no_char ldr w1, [x0, #R_UART_RX] mov w0, w1 ret no_char: mov w0, #ERROR_NO_PENDING_CHAR ret endfunc console_cdns_core_getc /* --------------------------------------------- * int console_cdns_getc(console_t *console) * Function to get a character from the console. * It returns the character grabbed on success * or -1 if no character is available. * In : x0 - pointer to console_t structure * Out: w0 - character if available, else -1 * Clobber list : x0, x1 * --------------------------------------------- */ func console_cdns_getc #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ ldr x0, [x0, #CONSOLE_T_BASE] b console_cdns_core_getc endfunc console_cdns_getc /* --------------------------------------------- * void console_cdns_core_flush(uintptr_t base_addr) * Function to force a write of all buffered * data that hasn't been output. * In : x0 - console base address * Out : void * Clobber list : x0, x1 * --------------------------------------------- */ func console_cdns_core_flush #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ /* Loop until the transmit FIFO is empty */ check_txfifo_empty: ldr w2, [x0, #R_UART_SR] tbz w2, #UART_SR_INTR_TEMPTY_BIT, check_txfifo_empty /* Wait until the Transmit is Inactive */ check_tx_inactive_state: ldr w2, [x0, #R_UART_SR] tbnz w2, #UART_SR_INTR_TACTIVE_BIT, check_tx_inactive_state ret endfunc console_cdns_core_flush /* --------------------------------------------- * void console_cdns_flush(console_t *console) * Function to force a write of all buffered * data that hasn't been output. * In : x0 - pointer to console_t structure * Out : void. * Clobber list : x0, x1 * --------------------------------------------- */ func console_cdns_flush #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ ldr x0, [x0, #CONSOLE_T_BASE] b console_cdns_core_flush endfunc console_cdns_flush