robinkrens.nl - git repository - cortex-from-scratch/blob - term.c

   1 #include <stdbool.h>
   2 #include <stddef.h>
   3 #include <stdint.h>
   4 #include <stm32.h>
   5 #include <mmap.h>
   6
   7 #define SERIAL 1
   8 #define BUFSIZE 256
   9
  10 static char buf[BUFSIZE];
  11
  12 /* Abstraction layer for I/O communication */
  13
  14 char getchar(void) {
  15         char c;
  16         if (SERIAL) {
  17                  while ((c = uart_getc()) == 0);
  18                 /* do nothing */
  19         }
  20         return c;
  21 }
  22
  23 void cputchar(char c) {
  24
  25         if (SERIAL) {
  26                 uart_putc(c);
  27         }
  28
  29 }
  30
  31 void cputs(unsigned char *str) {
  32
  33      int i;
  34      for (i = 0; i < strlen(str); i++)     {
  35          cputchar(str[i]);
  36     }
  37
  38 }
  39
  40 void terminal() {
  41
  42         char *buf;
  43         cputs("Terminal running!\n");
  44
  45          while (1) {
  46                  buf = readline("> ");
  47                  /* if (buf != NULL)
  48                          if (runcmd(buf, tf) < 0)
  49                                  break; */
  50          }
  51 }
  52
  53 char * readline(char *prompt)
  54 {
  55         int i, c, echoing;
  56
  57         if (prompt != NULL)
  58                 cputs(prompt);
  59
  60         i = 0;
  61         echoing = 1;
  62         while (1) {
  63                 c = getchar();
  64                 if (c < 0) {
  65                         cputs("read error");
  66                         return NULL;
  67                 } else if ((c == '\b' || c == '\x7f') && i > 0) {
  68                         if (echoing)
  69                                 cputchar('\b');
  70                         i--;
  71                 } else if (c >= ' ' && i < BUFSIZE-1) {
  72                         if (echoing)
  73                                 cputchar(c);
  74                         buf[i++] = c;
  75                 } else if (c == '\n' || c == '\r') {
  76                         if (echoing)
  77                                 cputchar('\n');
  78                         buf[i] = 0;
  79                         return buf;
  80                 }
  81         }
  82 }