#include "stm32f411.h"

static const char *text[] = {
  "hello, friend.\r\n",
  "hello, friend?\r\n",
  "that's lame.\r\n",
  "maybe i should give you a name.\r\n",
  "but that's a slippery slope.\r\n",
  "you're only in my head.\r\n",
  "we have to remember that.\r\n",
  "shit.\r\n",
  "it's actually happening, i'm talking to an imaginary person.\r\n\n"
};

void
kentry (void)
{
  unsigned int line, off;

  /*  Test UART and LED  ----------------------------------------------------  */

  while (1)
    {
      for (line = 0; line < sizeof text / sizeof *text; ++line)
        {
          /* Print current line  */
          off = 0;
          while (text[line][off])
            {
              /* TXE: Transmit data register empty  */
              while (!(*USART1_SR & (1u << 7))); /* 0: Data is not transferred
                                                    to the shift register  */

              /* DR[8:0]: Data value  */
              *USART1_DR = text[line][off++];
            }

          /* TC: Transmission complete  */
          while (!(*USART1_SR & (1u << 6))); /* 0: Transmission is not
                                                complete  */

          /* Blink LED  */
          *GPIOC_ODR ^= (1u << 13);
        }
    }
}