neorv32/sw/example/demo_newlib/main.c
2024-06-21 20:17:16 +02:00

120 lines
4.5 KiB
C

// ================================================================================ //
// The NEORV32 RISC-V Processor - https://github.com/stnolting/neorv32 //
// Copyright (c) NEORV32 contributors. //
// Copyright (c) 2020 - 2024 Stephan Nolting. All rights reserved. //
// Licensed under the BSD-3-Clause license, see LICENSE for details. //
// SPDX-License-Identifier: BSD-3-Clause //
// ================================================================================ //
/**********************************************************************//**
* @file demo_newlib/main.c
* @author Stephan Nolting
* @brief Demo/test program for NEORV32's newlib C standard library support.
**************************************************************************/
#include <neorv32.h>
#include <unistd.h>
#include <stdlib.h>
/**********************************************************************//**
* @name User configuration
**************************************************************************/
/**@{*/
/** UART BAUD rate */
#define BAUD_RATE 19200
/**@}*/
/**********************************************************************//**
* @name Max heap size (from linker script's "__neorv32_heap_size")
**************************************************************************/
extern char __crt0_max_heap[];
/**********************************************************************//**
* Main function: Check some of newlib's core functions.
*
* @note This program requires UART0.
*
* @return 0 if execution was successful
**************************************************************************/
int main() {
// setup NEORV32 runtime environment to keep us safe
// -> catch all traps and give debug information via UART0
neorv32_rte_setup();
// setup UART at default baud rate, no interrupts
neorv32_uart0_setup(BAUD_RATE, 0);
// check if UART0 is implemented at all
if (neorv32_uart0_available() == 0) {
neorv32_uart0_printf("Error! UART0 not synthesized!\n");
return 1;
}
// say hello
neorv32_uart0_printf("<<< Newlib demo/test program >>>\n\n");
// heap size definition
volatile uint32_t max_heap = (uint32_t)__crt0_max_heap;
if (max_heap > 0){
neorv32_uart0_printf("MAX heap size: %u bytes\n", max_heap);
}
else {
neorv32_uart0_printf("ERROR! No heap size defined (USER_FLAGS+='-Wl,--defsym,__neorv32_heap_size=1024')!\n");
return -1;
}
// check if newlib is really available
#ifndef __NEWLIB__
neorv32_uart0_printf("ERROR! Seems like the compiler toolchain does not support newlib...\n");
return -1;
#endif
neorv32_uart0_printf("newlib version %i.%i\n\n", (int32_t)__NEWLIB__, (int32_t)__NEWLIB_MINOR__);
neorv32_uart0_printf("<rand> test... ");
srand(neorv32_cpu_csr_read(CSR_CYCLE)); // set random seed
neorv32_uart0_printf("%i, %i, %i, %i\n", rand() % 100, rand() % 100, rand() % 100, rand() % 100);
char *char_buffer; // pointer for dynamic memory allocation
neorv32_uart0_printf("<malloc> test...\n");
char_buffer = (char *) malloc(4 * sizeof(char)); // 4 bytes
// do not test read & write in simulation as there would be no UART RX input
if (neorv32_cpu_csr_read(CSR_MXISA) & (1 << CSR_MXISA_IS_SIM)) {
neorv32_uart0_printf("Skipping <read> & <write> tests as this seems to be a simulation.\n");
}
else {
neorv32_uart0_printf("<read> test (waiting for 4 chars via UART0)... ");
read((int)STDIN_FILENO, char_buffer, 4 * sizeof(char)); // get 4 chars from "STDIN" (UART0.RX)
neorv32_uart0_printf("ok\n");
neorv32_uart0_printf("<write> test to 'STDOUT'... (outputting the chars you have send)\n");
write((int)STDOUT_FILENO, char_buffer, 4 * sizeof(char)); // send 4 chars to "STDOUT" (UART0.TX)
neorv32_uart0_printf("\nok\n");
neorv32_uart0_printf("<write> test to 'STDERR'... (outputting the chars you have send)\n");
write((int)STDERR_FILENO, char_buffer, 4 * sizeof(char)); // send 4 chars to "STDERR" (UART0.TX)
neorv32_uart0_printf("\nok\n");
}
neorv32_uart0_printf("<free> test...\n");
free(char_buffer);
// NOTE: exit is highly over-sized as it also includes clean-up functions (destructors), which
// are not required for bare-metal or RTOS applications... better use the simple 'return' or even better
// make sure main never returns. Anyway, let's check if 'exit' works.
neorv32_uart0_printf("terminating via <exit> ");
exit(0);
// should never be reached
neorv32_uart0_printf("failed!n");
return 0;
}