| Sandrine Bailleux | 3cd87d7 | 2018-10-09 11:12:55 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2018, Arm Limited. All rights reserved. |
| 3 | * |
| 4 | * SPDX-License-Identifier: BSD-3-Clause |
| 5 | */ |
| 6 | |
| 7 | #include "asm_macros.S" |
| 8 | #include "platform.h" |
| 9 | |
| 10 | /* |
| 11 | * PL011 UART registers |
| 12 | */ |
| 13 | /* UART Flag Register */ |
| 14 | #define UARTFR 0x018 |
| 15 | /* Transmit FIFO full bit in UARTFR register */ |
| 16 | #define PL011_UARTFR_TXFF_BIT 5 |
| 17 | /* UART Data Register */ |
| 18 | #define UARTDR 0x000 |
| 19 | |
| 20 | .text |
| 21 | .global print_string |
| 22 | .global print_char |
| 23 | |
| 24 | /* |
| 25 | * void print_char(unsigned int c); |
| 26 | * clobbers: x3, x4 |
| 27 | */ |
| 28 | func print_char |
| 29 | ldr x3, =UART_BASE |
| 30 | 1: |
| 31 | /* Check if the transmit FIFO is full */ |
| 32 | ldr w4, [x3, #UARTFR] |
| 33 | tbnz w4, #PL011_UARTFR_TXFF_BIT, 1b |
| 34 | str w0, [x3, #UARTDR] |
| 35 | ret |
| 36 | endfunc print_char |
| 37 | |
| 38 | /* |
| 39 | * void print_string(const char *str); |
| 40 | * clobbers: x0, x1, x2, x9 |
| 41 | */ |
| 42 | func print_string |
| 43 | ldr x1, =UART_BASE |
| 44 | mov x2, x0 |
| 45 | 1: |
| 46 | ldrb w0, [x2], #1 |
| 47 | cmp wzr, w0 |
| 48 | b.eq 2f |
| 49 | |
| 50 | mov x9, x30 |
| 51 | bl print_char |
| 52 | mov x30, x9 |
| 53 | b 1b |
| 54 | 2: |
| 55 | ret |
| 56 | endfunc print_string |