arch/all-pc/kernel/_displayalert.c

   1 #include <bootconsole.h>
   2 #include <inttypes.h>
   3
   4 #include <kernel_base.h>
   5 #include <kernel_debug.h>
   6 #include "alert_arch.h"
   7
   8 /*
   9  * Display alert on the screen using libbootconsole.
  10  * Very useful for early alerts, while the display driver not started yet.
  11  * In this case the user gets a nice GURU. Not painted in red yet. :)
  12  */
  13
  14 static inline void PrintChars(char c, ULONG n, struct KernelBase *KernelBase)
  15 {
  16     while (n--)
  17         krnPutC(c, KernelBase);
  18 }
  19
  20 /*
  21  * This function calculates length of line.
  22  * It's similar to strlen(), but stops also at LF and FF codes.
  23  */
  24 static inline int linelen(const char *str)
  25 {
  26     int l;
  27
  28     for (l = 0; str[l] && str[l] != '\n' && str[l] != 0x0F; l++);
  29     return l;
  30 }
  31
  32 static const char *PrintCentered(const char *str, struct KernelBase *KernelBase)
  33 {
  34     int len = linelen(str);
  35     int i;
  36     ULONG s;
  37
  38     if (len > (scr_Width - 2))
  39             len = (scr_Width - 2);
  40
  41     s = scr_Width - 2 - len;
  42
  43     krnPutC(0xDB, KernelBase);
  44     if (s & 1)
  45         krnPutC(' ', KernelBase);
  46     s >>= 1;
  47     PrintChars(' ', s, KernelBase);
  48
  49     for (i = 0; i < len; i++)
  50         krnPutC(*str++, KernelBase);
  51
  52     PrintChars(' ', s, KernelBase);
  53     krnPutC(0xDB, KernelBase);
  54     krnPutC('\n', KernelBase);
  55
  56     return str;
  57 }
  58
  59 static inline void PrintFrame(char c, struct KernelBase *KernelBase)
  60 {
  61     krnPutC(0xDB, KernelBase);
  62     PrintChars(c, scr_Width - 2, KernelBase);
  63     krnPutC(0xDB, KernelBase);
  64     krnPutC('\n', KernelBase);
  65 }
  66
  67 void krnDisplayAlert(const char *text, struct KernelBase *KernelBase)
  68 {
  69     unsigned int i;
  70
  71     if (scr_Type == SCR_UNKNOWN)
  72     {
  73         /* Default alert width (for possible serial output). */
  74         scr_Width = 80;
  75     }
  76
  77     /* Make sure that the output starts from a new line */
  78     krnPutC('\n', KernelBase);
  79
  80     PrintFrame(0xDF, KernelBase);
  81
  82     /* Print first three lines (title, task and error) centered */
  83     for (i = 0; i < 3; i++)
  84     {
  85         text = PrintCentered(text, KernelBase);
  86         if (*text == 0) /* Handle early NULL terminator */
  87             break;
  88         text++; /* Skip a newline */
  89     }
  90
  91     PrintFrame(0xDC, KernelBase);
  92
  93     /* Print the rest of alert text (if any) */
  94     if (*text)
  95     {
  96         PrintString(text, KernelBase);
  97
  98         /* Print a line in the bottom */
  99         krnPutC('\n', KernelBase);
 100         PrintChars(0xDC, scr_Width, KernelBase);
 101         krnPutC('\n', KernelBase);
 102     }
 103 }