suppress checking for LBA support via INT13,41 if LBA disabled by user

doc/fdisk/CHANGES.md

@@ -8,6 +8,14 @@ Bug classification:
  - LOW: Cosmetic bugs, like display issues etc.
 
 
+Version 1.3.14 (2024-02-04)
+---------------------------
+Fixes:
+ - HIGH: Prevent querying LBA capabilities via INT13,41 if LBA is disabled
+     by the user via command line argument /X. This caused some broken
+     BIOS to crash the system, like BIOS version 0.9.4 of Book8088 and Xi8088.
+
+
 Version 1.3.13 (2024-01-16)
 ---------------------------
 Changes:

source/fdisk/cmd.c

@@ -514,35 +514,6 @@ void Command_Line_Test_Flag( void )
    }
 }
 
-/* /X command line option */
-void Command_Line_X( void )
-{
-   int index;
-
-   /* Ask the user if FAT32 is desired. */
-   /*if ( ( flags.version == W95B ) || ( flags.version == W98 ) ) {
-      Ask_User_About_FAT32_Support();
-   }*/
-
-   flags.use_extended_int_13 = FALSE;
-   index = 0;
-   do {
-      part_table[index].ext_int_13 = FALSE;
-      index++;
-   } while ( index < MAX_DISKS );
-
-   if ( Read_Partition_Tables() != 0 ) {
-      /* NLS:Error reading partition tables. */
-      con_print( svarlang_str( 255, 0 ) );
-      exit( 1 );
-   }
-   /*if ( flags.maximum_drive_number == 0 ) {
-      Color_Print( "\n    No fixed disks present.\n" );
-      exit( 6 );
-   }
-
-   Interactive_User_Interface();*/
-}
 
 /* Get the command line options */
 int Get_Options( char *argv[], int argc )

source/fdisk/cmd.h

@@ -45,7 +45,6 @@ void Command_Line_Status( void );
 void Command_Line_Move( void );
 void Command_Line_Swap( void );
 void Command_Line_Test_Flag( void );
-void Command_Line_X( void );
 void Shift_Command_Line_Options( int number_of_places );
 
 #endif /* CMD_H */

source/fdisk/main.c

@@ -243,7 +243,7 @@ static int Get_Environment_Settings( char *environment[] )
 }
 
 /* Initialize flags, variables, load fdisk.ini, load part.ini, etc. */
-static void Initialization( char *environment[] )
+static void InitOptions( char *environment[] )
 {
    int index;
 
@@ -258,6 +258,7 @@ static void Initialization( char *environment[] )
    flags.use_iui = TRUE;
    flags.using_default_drive_number = TRUE;
    flags.version = COMP_W95B;
+   flags.use_extended_int_13 = TRUE;
 
    /* Clear the user_defined_chs_settings structure */
    index = 0;
@@ -284,21 +285,21 @@ static void Initialization( char *environment[] )
    /* monochrome mode, if it is desired. */
    con_enable_attr( !flags.monochrome );
 
-   /* Check for interrupt 0x13 extensions (If the proper version is set.) */
-   if ( flags.version >= COMP_W95 ) {
-      Check_For_INT13_Extensions();
-   }
-
    /* If the version is W95B or later then default to FAT32 support.  */
    if ( flags.version >= COMP_W95B ) {
       flags.fat32 = TRUE;
    }
+}
 
-   /* Initialize LBA structures, if necessary. */
-   if ( flags.use_extended_int_13 == TRUE ) {
-      Initialize_LBA_Structures();
+static void InitDisks( void )
+{
+   /* Check for interrupt 0x13 extensions (If the proper version is set.) */
+   if ( flags.version >= COMP_W95 ) {
+      Check_For_INT13_Extensions();
    }
 
+   Initialize_LBA_Structures();
+
    if ( Read_Partition_Tables() != 0 ) {
       con_puts( svarlang_str(255, 0) );
       exit( 1 );
@@ -307,9 +308,10 @@ static void Initialization( char *environment[] )
    if ( flags.maximum_drive_number == 0 ) {
       con_puts( svarlang_str(255, 1) );
       exit( 6 );
-   }
+   }   
 }
 
+
 /* Reboot the PC */
 void Reboot_PC( void )
 {
@@ -360,6 +362,7 @@ static void Ensure_Drive_Number( void )
 */
 int main( int argc, char *argv[] )
 {
+   char **argp;
    int command_ok;
    int index;
    int location;
@@ -451,9 +454,21 @@ int main( int argc, char *argv[] )
    else {
       path[0] = 0;
    }
+
+   InitOptions( environ );
+
+   /* Check if LBA is forbidden by the user before querying BIOS
+      capabilities, because some BIOS INT13,41h is broken, like
+      XT-IDE 2.03 beta without LBA support */
+   argp = argv+1;
+   while ( *argp ) {
+      if ( !strcmp( *argp, "/x" ) || !strcmp( *argp, "/X" ) ) {
+         flags.use_extended_int_13 = FALSE;
+      }
+      argp++;
+   }
 
-   Initialization( environ );
-
+   InitDisks();
 
    /* New Parsing Routine */
    /* The command line format is:                                            */
@@ -485,11 +500,9 @@ int main( int argc, char *argv[] )
          }
 
          if ( 0 == strcmp( arg[0].choice, "ACTOK" ) ) {
-            /*
-               if ( ( flags.version == W95B ) || ( flags.version == W98 ) ) {
-                  Ask_User_About_FAT32_Support();
-               }
-               */
+            /* ignored */
+            command_ok = TRUE;
+            Shift_Command_Line_Options( 1 );
          }
 
          if ( 0 == strcmp( arg[0].choice, "AUTO" ) ) {
@@ -796,7 +809,8 @@ int main( int argc, char *argv[] )
 #endif
 
          if ( 0 == strcmp( arg[0].choice, "X" ) ) {
-            Command_Line_X();
+            /* handled above, but still have to check to not misdetect
+               it as invalid parameter */
             Shift_Command_Line_Options( 1 );
             command_ok = TRUE;
          }

source/fdisk/main.h

@@ -4,7 +4,7 @@
   #define FD_NAME "Free FDISK"
 #endif
 
-#define VERSION  "1.3.13"
+#define VERSION  "1.3.14"
 #define COPYLEFT "1998 - 2024"
 
 #define SIZE_OF_IPL ( 512 - 4 * 16 - 2 - 6 )

source/fdisk/pdiskio.c

@@ -110,22 +110,24 @@ void Check_For_INT13_Extensions( void )
 
    pDrive = part_table;
 
+   memset( &r, 0, sizeof(r) );
    for ( drive = 0x80; drive < 0x88; drive++, pDrive++ ) {
-      r.h.ah = 0x41;
-      r.w.bx = 0x55aa;
-      r.h.dl = drive;
-      intr( 0x13, &r );
-
       pDrive->ext_int_13 = FALSE;
       pDrive->ext_int_13_version = 0;
 
-      if ( ( ( r.w.flags & INTR_CF ) == 0 ) && ( r.w.bx == 0xaa55 ) ) {
-         flags.use_extended_int_13 = TRUE;
-         pDrive->ext_int_13_version = r.h.ah;
-
-         if ( ( r.w.cx & 1 ) == 1 ) {
-            /* ext INT 13 functions 42, 43 and 48 actually usable? */
-            pDrive->ext_int_13 = TRUE;
+      if ( flags.use_extended_int_13 ) {
+         r.h.ah = 0x41;
+         r.w.bx = 0x55aa;
+         r.h.dl = drive;
+         intr( 0x13, &r );
+
+         if ( ( ( r.w.flags & INTR_CF ) == 0 ) && ( r.w.bx == 0xaa55 ) ) {
+            pDrive->ext_int_13_version = r.h.ah;
+
+            if ( ( r.w.cx & 1 ) == 1 ) {
+               /* ext INT 13 functions 42, 43 and 48 actually usable? */
+               pDrive->ext_int_13 = TRUE;
+            }
          }
       }
    }