st3m_console.c

#include "st3m_console.h"

#include <sys/fcntl.h>
#include <sys/errno.h>

#include "esp_vfs.h"
#include "esp_vfs_dev.h"
#include "esp_log.h"
#include "esp_timer.h"
#include "driver/uart.h"
#include "freertos/FreeRTOS.h"
#include "freertos/ringbuf.h"
#include "freertos/semphr.h"

static const char *TAG = "st3m-console";
static const uart_port_t uart_num = UART_NUM_0;
static esp_vfs_t _vfs;


typedef struct {
	int flags;
} st3m_console_file_t;

typedef struct {
	SemaphoreHandle_t mu;
	RingbufHandle_t txbuf;
	RingbufHandle_t rxbuf;

	st3m_console_file_t fstdin;
	st3m_console_file_t fstdout;
	st3m_console_file_t fstderr;

	int64_t cdc_last_read;

	int64_t cdc_first_read_at;
} st3m_console_state_t;

static st3m_console_state_t _state = {
	.mu = NULL,
	.txbuf = NULL,
	.rxbuf = NULL,

	.fstdin = { 0 },
	.fstdout = { 0 },
	.fstderr = { 0 },

	.cdc_last_read = 0,
	.cdc_first_read_at = 0,
};

static void _uart0_write(const char *buffer, size_t bufsize) {
	// Skip entire writes that would block, as we don't want to limit stdout
	// speed to 115200 baud.
	size_t free_bytes = 0;
	uart_get_tx_buffer_free_size(uart_num, &free_bytes);
	if (bufsize > free_bytes) {
		return;
	}

	uart_write_bytes(uart_num, buffer, bufsize);
}

int st3m_uart0_debug(const char *fmt, ...) {
	va_list args;
    va_start(args, fmt);

	char buf[256];
	memset(buf, 0, 256);
	vsnprintf(buf, 256, fmt, args);
	_uart0_write(buf, strlen(buf));