rom/kernel/_displayalert.c

   1 #include <kernel_base.h>
   2 #include <kernel_debug.h>
   3
   4 #define ALERT_WIDTH 80
   5
   6 static inline void PrintChars(char c, ULONG n, struct KernelBase *KernelBase)
   7 {
   8     while (n--)
   9         krnPutC(c, KernelBase);
  10 }
  11
  12 /*
  13  * This function calculates length of line.
  14  * It's similar to strlen(), but stops also at LF and FF codes.
  15  */
  16 static inline int linelen(const char *str)
  17 {
  18     int l;
  19
  20     for (l = 0; str[l] && str[l] != '\n' && str[l] != 0x0F; l++);
  21     return l;
  22 }
  23
  24 static const char *PrintCentered(const char *str, struct KernelBase *KernelBase)
  25 {
  26     int len = linelen(str);
  27     int i;
  28     ULONG s;
  29
  30     if (len > (ALERT_WIDTH - 2))
  31             len = (ALERT_WIDTH - 2);
  32
  33     s = ALERT_WIDTH - 2 - len;
  34
  35     krnPutC('#', KernelBase);
  36     if (s & 1)
  37         krnPutC(' ', KernelBase);
  38     s >>= 1;
  39     PrintChars(' ', s, KernelBase);
  40
  41     for (i = 0; i < len; i++)
  42         krnPutC(*str++, KernelBase);
  43
  44     PrintChars(' ', s, KernelBase);
  45     krnPutC('#', KernelBase);
  46     krnPutC('\n', KernelBase);
  47
  48     return str;
  49 }
  50
  51 static inline void PrintFrame(struct KernelBase *KernelBase)
  52 {
  53     PrintChars('#', ALERT_WIDTH, KernelBase);
  54     krnPutC('\n', KernelBase);
  55 }
  56
  57 /*
  58  * This entry point just displays the message. It doesn't make any decisions
  59  * what to do next.
  60  * Because of this it misses 'code' argument.
  61  * The kernel can use it internally, for displaying messages about
  62  * critical startup failures.
  63  */
  64 void krnDisplayAlert(const char *text, struct KernelBase *KernelBase)
  65 {
  66     unsigned int i;
  67
  68     /* Make sure that the output starts from a new line */
  69     krnPutC('\n', KernelBase);
  70
  71     PrintFrame(KernelBase);
  72
  73     /* Print first three lines (title, task and error) centered */
  74     for (i = 0; i < 3; i++)
  75     {
  76         text = PrintCentered(text, KernelBase);
  77
  78         if (*text == 0) /* Handle early NULL terminator */
  79             break;
  80
  81         text++; /* Skip a newline */
  82     }
  83
  84     PrintFrame(KernelBase);
  85
  86     /* Print the rest of alert text (if any) */
  87     if (*text)
  88     {
  89         while (*text)
  90             krnPutC(*text++, KernelBase);
  91
  92         krnPutC('\n', KernelBase);
  93         PrintFrame(KernelBase);
  94     }
  95 }