+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <sys/mmap.h>
+#include <sys/robsys.h>
+
+#include <lib/regfunc.h>
+#include <lib/string.h>
+
+#include <drivers/uart.h>
+
+#define RXNE ((*USART1_SR >> 5) & 0x1)
+#define UARTBUF 256
+#define ECHO 1
+
+static struct {
+ uint8_t buf[UARTBUF];
+ uint32_t rpos;
+ uint32_t wpos;
+} linefeed;
+
+
+void * uart_handler() {
+
+ //uart_puts("echo: ");
+ while (RXNE) {
+ char echochar = *USART1_DR;
+// uart_putc(echochar);
+ linefeed.buf[linefeed.wpos++] = echochar;
+ if (linefeed.wpos == UARTBUF)
+ linefeed.wpos = 0;
+ //regw_u32(USART1_DR, echochar, 0, O_WRITE);
+ }
+ //uart_putc('\n');
+
+}
+
+void uart_init() {
+
+ linefeed.rpos = 0;
+ linefeed.wpos = 0;
+
+ //memset(&linefeed, 0, (sizeof(struct linefeed) ));
+ regw_u32(RCC_APB2ENR, 0x4005, 0, SETBIT);// enable clock to UART1, AFIO and GPIOA
+
+ /* (after enable GPIOA), on PA9&PA10 and set mode
+ * to alternative output */
+ regw_u32(GPIOA_CRH, 0x444444D4, 0, OWRITE);
+ regw_u8(AFIO_EVCR, 0x89, 0, OWRITE);// set event control register, output on PA, Pin 9
+
+ //disable temporarily to set values
+ regw_u8(USART1_CR1, 0x0, 13, SETBIT);
+
+ /* baud rate 115200, 8MHz / (16 * USARTDIV)
+ * USARTDIV = 4.34
+ * FRACTION: 16 x 0.34 = 0d5.44 0d5 -> 0x5
+ * MANTISSA: 0d4.34 0d4 -> 0x4
+ * USART_BRR = 0x45*/
+
+ regw_u32(USART1_BRR, 0x00000045, 0, OWRITE);
+ regw_u32(USART1_CR2, 0x0000, 0, OWRITE); //set stop bit, default is 1 stop bit 0x00
+
+ /* parity = 8 bit, UART1 enabled,
+ * TX and RX enabled, interrupts enabled */
+ //regw_u32(USART1_CR1, 0x000030AC, 0, O_WRITE);
+ regw_u32(USART1_CR1, 0x0000302C, 0, OWRITE);
+
+ ivt_set_gate(53, uart_handler, 0);
+
+ *NVIC_ISER1 = (1 << 5); // Enable UART interrupt at NVIC
+}
+
+static void wait() {
+ for (int i = 0; i < 100; i++);
+}
+
+extern void uart_putc(unsigned char ch) {
+
+ if (ch == '\n') {
+ while (*USART1_SR & 0x0C) { } // transmit data register empty and complete
+ regw_u8(USART1_DR, 0x0D, 0, OWRITE); // return line
+ }
+
+ while (*USART1_SR & 0x0C) {}
+ regw_u8(USART1_DR, ch, 0, OWRITE);
+
+ wait();
+}
+
+char uart_getc(void) {
+ char c;
+
+ if (linefeed.rpos != linefeed.wpos) {
+ c = linefeed.buf[linefeed.rpos++];
+ if (linefeed.rpos == UARTBUF)
+ linefeed.rpos = 0;
+ return c;
+ }
+ return 0;
+ }
+
+
+// move to library
+extern void uart_puts(unsigned char *str) {
+ int i;
+ for (i = 0; i < strlen(str); i++) {
+ uart_putc(str[i]);
+ }
+}
+