src/rp2_common/pico_stdio_semihosting/stdio_semihosting.c

/*
 * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include "pico/stdio/driver.h"
#include "pico/stdio_semihosting.h"
#include "pico/binary_info.h"

//static void __attribute__((naked)) semihosting_puts(const char *s) {
//    __asm (
//
//    "mov r1, r0\n"
//    "mov r0, #4\n"
//    "bkpt 0xab\n"
//    "bx lr\n"
//    );
//}

static void __attribute__((naked)) semihosting_putc(char c) {
    __asm (

    "mov r1, r0\n"
    "mov r0, #3\n"
    "bkpt 0xab\n"
    "bx lr\n"
    );
}


static void stdio_semihosting_out_chars(const char *buf, int length) {
    for (uint i = 0; i <length; i++) {
        semihosting_putc(buf[i]);
    }
}

stdio_driver_t stdio_semihosting = {
        .out_chars = stdio_semihosting_out_chars,
#if PICO_STDIO_ENABLE_CRLF_SUPPORT
        .crlf_enabled = PICO_STDIO_SEMIHOSTING_DEFAULT_CRLF
#endif
};

void stdio_semihosting_init() {
#if !PICO_NO_BI_STDIO_SEMIHOSTING
    bi_decl_if_func_used(bi_program_feature("semihosting stdout"));
#endif
    stdio_set_driver_enabled(&stdio_semihosting, true);
}