Bug fixes in the geometry detection. Linux video mode selection support. New Stage 1 stage1_lba is added. Stage 1.5 becomes much smaller.

stage2/bios.c

@@ -118,6 +118,9 @@ int
 get_diskinfo (int drive, struct geometry *geometry)
 {
   int err;
+
+  /* Clear the flags.  */
+  geometry->flags = 0;
   
   if (drive & 0x80)
     {
@@ -159,11 +162,7 @@ get_diskinfo (int drive, struct geometry *geometry)
 	      
 	      /* Check if CHS information is valid.  */
 	      if (drp.flags & 0x02)
-		{
-		  total_sectors = (geometry->cylinders
-				   * geometry->heads
-				   * geometry->sectors);
-		}
+		total_sectors = drp.cylinders * drp.heads * drp.sectors;
 	    }
 	}
 

stage2/boot.c

@@ -198,6 +198,44 @@ load_image (void)
 
       if (mbi.mem_lower >= 608)
 	{
+	  /* Video mode selection support. What a shit!  */
+	  {
+	    char *vga;
+
+	    /* Find the substring "vga=".  */
+	    vga = grub_strstr (cur_cmdline, "vga=");
+	    if (vga)
+	      {
+		char *value = vga + 4;
+		char *vga_end;
+		int vid_mode;
+
+		/* Handle special strings.  */
+		if (substring ("normal", value) < 1)
+		  vid_mode = LINUX_VID_MODE_NORMAL;
+		else if (substring ("ext", value) < 1)
+		  vid_mode = LINUX_VID_MODE_EXTENDED;
+		else if (substring ("ask", value) < 1)
+		  vid_mode = LINUX_VID_MODE_ASK;
+		else if (safe_parse_maxint (&value, &vid_mode))
+		  ;
+		else
+		  /* ERRNUM is already set inside the function
+		     safe_parse_maxint.  */
+		  return 0;
+
+		/* Set the vid mode to VID_MODE. Note that this can work
+		   because i386 architecture is little-endian.  */
+		grub_memmove (buffer + LINUX_VID_MODE_OFFSET,
+			      (char *) &vid_mode,
+			      sizeof (unsigned short));
+		
+		/* Remove the "vga=...".  */
+		vga_end = skip_to (0, vga);
+		grub_memmove (vga, vga_end, grub_strlen (vga_end));
+	      }
+	  }
+		
 	  memmove ((char *) LINUX_SETUP, buffer, data_len + SECTOR_SIZE);
 
 	  /* copy command-line plus memory hack to staging area */

stage2/char_io.c

@@ -31,7 +31,7 @@ print_error (void)
     /* printf("\7\n %s\n", err_list[errnum]); */
     printf ("\n %s\n", err_list[errnum]);
 #else /* STAGE1_5 */
-    printf ("Error: %d\n", errnum);
+    printf ("Error: %u\n", errnum);
 #endif /* STAGE1_5 */
 
   errnum = ERR_NONE;
@@ -44,6 +44,7 @@ convert_to_ascii (char *buf, int c,...)
   unsigned long num = *((&c) + 1), mult = 10;
   char *ptr = buf;
 
+#ifndef STAGE1_5
   if (c == 'x')
     mult = 16;
 
@@ -53,6 +54,7 @@ convert_to_ascii (char *buf, int c,...)
       *(ptr++) = '-';
       buf++;
     }
+#endif
 
   do
     {
@@ -80,7 +82,7 @@ convert_to_ascii (char *buf, int c,...)
 
 
 void
-grub_printf (char *format,...)
+grub_printf (const char *format,...)
 {
   int *dataptr = (int *) &format;
   char c, *ptr, str[16];
@@ -94,9 +96,11 @@ grub_printf (char *format,...)
       else
 	switch (c = *(format++))
 	  {
+#ifndef STAGE1_5
 	  case 'd':
-	  case 'u':
 	  case 'x':
+#endif
+	  case 'u':
 	    *convert_to_ascii (str, c, *((unsigned long *) dataptr++)) = 0;
 
 	    ptr = str;
@@ -422,39 +426,11 @@ get_cmdline (char *prompt, char *commands, char *cmdline, int maxlen,
 #endif /* STAGE1_5 */
 
 
-int
-get_based_digit (int c, int base)
-{
-  int digit = -1;
-
-  /* make sure letter in the the range we can check! */
-  c = tolower (c);
-
-  /*
-   *  Is it in the range between zero and nine?
-   */
-  if (base > 0 && c >= '0' && c <= '9' && c < (base + '0'))
-    {
-      digit = c - '0';
-    }
-
-  /*
-   *  Is it in the range used by a letter?
-   */
-  if (base > 10 && c >= 'a' && c <= 'z' && c < ((base - 10) + 'a'))
-    {
-      digit = c - 'a' + 10;
-    }
-
-  return digit;
-}
-
-
 int
 safe_parse_maxint (char **str_ptr, int *myint_ptr)
 {
-  register char *ptr = *str_ptr;
-  register int myint = 0, digit;
+  char *ptr = *str_ptr;
+  int myint = 0;
   int mult = 10, found = 0;
 
   /*
@@ -466,8 +442,22 @@ safe_parse_maxint (char **str_ptr, int *myint_ptr)
       mult = 16;
     }
 
-  while ((digit = get_based_digit (*ptr, mult)) != -1)
+  while (1)
     {
+      /* A bit tricky. This below makes use of the equivalence:
+	 (A >= B && A <= C) <=> ((A - B) <= (C - B))
+	 when C > B and A is unsigned.  */
+      unsigned int digit;
+      
+      digit = tolower (*ptr) - '0';
+      if (digit > 9)
+	{
+	  digit -= 'a' - '0';
+	  if (mult == 10 || digit > 5)
+	    break;
+	  digit += 10;
+	}
+
       found = 1;
       if (myint > ((MAXINT - digit) / mult))
 	{
@@ -513,7 +503,7 @@ grub_isspace (int c)
 
 #ifndef STAGE1_5
 int
-grub_strncat (char *s1, char *s2, int n)
+grub_strncat (char *s1, const char *s2, int n)
 {
   int i = -1;
 
@@ -533,7 +523,7 @@ grub_strncat (char *s1, char *s2, int n)
 
 
 int
-grub_strcmp (char *s1, char *s2)
+grub_strcmp (const char *s1, const char *s2)
 {
   while (*s1 || *s2)
     {
@@ -571,9 +561,9 @@ substring (char *s1, char *s2)
 
 #ifndef STAGE1_5
 char *
-grub_strstr (char *s1, char *s2)
+grub_strstr (const char *s1, const char *s2)
 {
-  char *ptr, *tmp;
+  const char *ptr, *tmp;
 
   while (*s1)
     {
@@ -583,11 +573,22 @@ grub_strstr (char *s1, char *s2)
       while (*s1 && *s1++ == *tmp++);
 
       if (tmp > s2 && !*(tmp - 1))
-	return ptr;
+	return (char *) ptr;
     }
 
   return 0;
 }
+
+int
+grub_strlen (const char *str)
+{
+  int len = 0;
+  
+  while (*str++)
+    len++;
+  
+  return len;
+}
 #endif /* ! STAGE1_5 */
 
 
@@ -616,31 +617,39 @@ memcheck (int start, int len)
 
 
 char *
-grub_memmove (char *to, char *from, int len)
+grub_memmove (char *to, const char *from, int len)
 {
-   char *ret = to;
    if (memcheck ((int) to, len))
      {
-       if ((to >= from + len) || (to <= from))
+       /* This assembly code is stolen from
+	  linux-2.2.2/include/asm-i386/string.h. This is not very fast
+	  but compact.  */
+       int d0, d1, d2;
+       
+       if (to < from)
 	 {
-	   while (len >= sizeof (unsigned long))
-	     {
-	       len -= sizeof (unsigned long);
-	       *(((unsigned long *) to)++) = *(((unsigned long *) from)++);
-	     }
-	   while (len-- > 0)
-	     *(to++) = *(from++);
+	   asm volatile ("cld\n\t"
+			 "rep\n\t"
+			 "movsb"
+			 : "=&c" (d0), "=&S" (d1), "=&D" (d2)
+			 : "0" (len),"1" (from),"2" (to)
+			 : "memory");
 	 }
        else
 	 {
-	   /* We have a region that overlaps, but would be overwritten
-	      if we copied it forward. */
-	   while (len-- > 0)
-	     to[len] = from[len];
+	   asm volatile ("std\n\t"
+			 "rep\n\t"
+			 "movsb\n\t"
+			 "cld"
+			 : "=&c" (d0), "=&S" (d1), "=&D" (d2)
+			 : "0" (len),
+			 "1" (len - 1 + from),
+			 "2" (len - 1 + to)
+			 : "memory");
 	 }
      }
 
-   return errnum ? NULL : ret;
+   return errnum ? NULL : to;
 }
 
 

stage2/shared.h

@@ -89,6 +89,12 @@ extern char *grub_scratch_mem;
 #define LINUX_SETUP_CODE_START    0x214
 #define LINUX_SETUP_INITRD        0x218
 
+/* Linux's video mode selection support. Actually I hate it!  */
+#define LINUX_VID_MODE_OFFSET	0x1FA
+#define LINUX_VID_MODE_NORMAL	0xFFFF
+#define LINUX_VID_MODE_EXTENDED	0xFFFE
+#define LINUX_VID_MODE_ASK	0xFFFD
+
 #define CL_MY_LOCATION  RAW_ADDR (0x92000)
 #define CL_MY_END_ADDR  RAW_ADDR (0x920FF)
 #define CL_MAGIC_ADDR   RAW_ADDR (0x90020)
@@ -235,6 +241,7 @@ extern char *grub_scratch_mem;
 #define strstr grub_strstr
 #define strcmp grub_strcmp
 #define tolower grub_tolower
+#define strlen grub_strlen
 #endif /* WITHOUT_LIBC_STUBS */
 
 
@@ -503,14 +510,15 @@ cmdline_t enter_cmdline (char *script, char *heap);
 #endif
 
 /* C library replacement functions with identical semantics. */
-void grub_printf (char *format,...);
+void grub_printf (const char *format,...);
 int grub_tolower (int c);
 int grub_isspace (int c);
-int grub_strncat (char *s1, char *s2, int n);
-char *grub_memmove (char *to, char *from, int len);
+int grub_strncat (char *s1, const char *s2, int n);
+char *grub_memmove (char *to, const char *from, int len);
 void *grub_memset (void *start, int c, int len);
-char *grub_strstr (char *s1, char *s2);
-int grub_strcmp (char *s1, char *s2);
+char *grub_strstr (const char *s1, const char *s2);
+int grub_strcmp (const char *s1, const char *s2);
+int grub_strlen (const char *str);
 
 /* misc */
 void init_page (void);