set backup boot sector on FAT32, add update option, fix oemboot to work with msdos 7+

git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/branches/UNSTABLE@1125 6ac86273-5f31-0410-b378-82cca8765d1b

boot/oemboot.asm

@@ -5,17 +5,20 @@
 ;                Copyright (c) 200?, <add name here>
 ; Description:
 ; OEM boot sector for FreeDOS compatible with IBM's (R) PC-DOS,
-; and Microsoft's (R) PC-DOS.  It may work with OpenDOS/DR-DOS,
+; and Microsoft's (R) MS-DOS.  It may work with older OpenDOS/DR-DOS,
-; although the standard FreeDOS boot sector works with later
+; although the standard FreeDOS boot sector is needed with ver 7+
 ; releases.  May work with other versions of DOS that use
 ; IBMBIO.COM/IBMDOS.COM pair.  This boot sector loads only up
 ; to 58 sectors (29KB) of the kernel (IBMBIO.COM) to 0x70:0 then
-; jumps to it.  As best I can tell, PC-DOS (and assuming MS-DOS
+; jumps to it.  As best I can tell, PC-DOS (and MS-DOS up to version
-; behaves similar) expects on entry for:
+; 6.xx behaves similar) expects on entry for:
 ; ch = media id byte in the boot sector
 ; dl = BIOS drive booted from (0x00=A:, 0x80=C:, ...)
-; ax:bx = the LBA sector of 1st data sector 0x0000:0021 for FAT12
+; ax:bx = the starting (LBA) sector of cluster 2 (ie the 1st
-; ?or? 1st sector of IBMBIO.COM (which is normally 1st data sector)
+; data sector, which is 0x0000:0021 for FAT12)
+; ?note? IBMBIO.COM/IO.SYS may use ax:bx and cluster # stored
+; elsewhere (perhaps dir entry still at 0x50:0) to determine
+; starting sector for full loading of kernel file.
 ; it also expects the boot sector (in particular the BPB)
 ; to still be at 0x0:7C00, the directory entry for IBMBIO.COM
 ; (generally first entry of first sector of the root directory)
@@ -24,6 +27,26 @@
 ; may fail for any systems where the changes (???) are needed.
 ; If the above conditions are not met, then IBMBIO.COM will
 ; print the not a bootable disk error message.
+;
+; For MS-DOS >= 7 (ie Win9x DOS) the following conditions
+; must be met:
+; bp = 0x7C00, ie offset boot sector loaded at
+; [bp-4] = the starting (LBA) sector of cluster 2 (ie the 1st
+; data sector [this is the same as ax:bx for earlier versions
+; and dx:ax in Win9x boot sector]
+; The starting cluster of the kernel file is stored in
+; di for FAT 12/16 (where si is a don't care) and si:di
+; for FAT 32.
+; The values for ax,bx,cx,dx,ds and the stack do not
+; seem to be important (used by IO.SYS) and so may be any value
+; (though dx:ax=[data_start], cx=0, bx=0x0f00 on FAT12 or
+; 0x0700 on FAT32, ds=0, ss:sp=0:7b??)
+
+; the boot time stack may store the original int1E floppy
+; parameter table, otherwise nothing else important seems
+; stored there and I am unsure if even this value is used
+; beyond boot sector code.
+
 ;
 ; This boot sector only supports FAT12/FAT16 as PC-DOS
 ; does not support FAT32 and newer FAT32 capable DOSes
@@ -78,29 +101,39 @@
 ;	|BOOT SEC| contains BPB
 ;	|ORIGIN  | 
 ;	|--------| 0000:7C00  (0:BP)
+;	|VARS    | only known is 1st data sector (start of cluster 2)
+;	|--------| 0000:7BFC  (DS:[BP-4])
 ;	|STACK   | minimal 256 bytes (1/2 sector)
 ;	|- - - - |
 ;	|KERNEL  | kernel loaded here (max 58 sectors, 29KB)
 ;	|LOADED  | also used as FAT buffer
 ;	|--------| 0070:0000 (0:0700)
 ;	|DOS DA/ | DOS Data Area,
-;	|ROOT DIR| during boot the 1st sector of root directory
+;	|ROOT DIR| during boot contains directory entries
 ;	|--------| 0000:0500
 ;	|BDA     | BIOS Data Area
 ;	+--------+ 0000:0400
 ;	|IVT     | Interrupt Vector Table
 ;	+--------+ 0000:0000
 
+CPU 8086  ; enable assembler warnings to limit instruction set
 
 ;%define ISFAT12         1              ; only 1 of these should be set,
 ;%define ISFAT16         1              ; defines which FAT is supported
 
 %define TRYLBAREAD       1              ; undefine to use only CHS int 13h
-;%define LOOPONERR       1              ; if defined on error simply loop forever
+%define SETROOTDIR       1              ; if defined dir entry copied to 0:500
-;%define SETROOTDIR      1              ; if defined dir entry copied to 0:500
+%define LOOPONERR        1              ; if defined on error simply loop forever
 ;%define RETRYALWAYS     1              ; if defined retries read forever
+;%define WINBOOT         1              ; use win9x kernel calling conventions (name & jmp addr)
 ;%define MSCOMPAT        1              ; sets default filename to MSDOS IO.SYS
 
+%ifdef WINBOOT                          ; if set also change from PC-DOS to 
+%ifndef MSCOMPAT                        ; kernel name to MS-DOS kernel name
+%define MSCOMPAT
+%endif
+%endif
+
 segment	.text
 
 %define BASE            0x7c00          ; boot sector originally at 0x0:BASE
@@ -133,7 +166,8 @@ segment	.text
 ;%define RootDirSecs      PARAMS+0x0        ; # of sectors root dir uses
 %define fat_start        PARAMS+0x2         ; first FAT sector
 ;%define root_dir_start   PARAMS+0x6        ; first root directory sector
-%define data_start       PARAMS+0x0a        ; first data sector
+%define first_cluster    PARAMS+0x0a        ; starting cluster of kernel file
+%define data_start       bp-4               ; first data sector (win9x expects here)
 
 ;-----------------------------------------------------------------------
 
@@ -203,20 +237,33 @@ real_start:
                 mov     es, ax
                 mov     ss, ax
                 mov     bp, BASE
-                lea     sp, [bp-2]
+                lea     sp, [bp-4] ; for DOS <7 this may be [bp]
-
-                                ; a reset should not be needed here
-;               int     0x13    ; reset drive
 
 ;       For compatibility, diskette parameter vector updated.
-;               lea     di  [bp+0x3E] ; just use bp for DR-DOS?
+;               lea     di  [bp+0x3E] ; use 7c3e([bp+3e]) for PC-DOS,
+;               ;lea     di  [bp]     ; but 7c00([bp]) for DR-DOS 7 bug
 ;               mov     bx, 4 * 1eh   ; stored at int 1E's vector
 ;               lds     si, [bx]      ; fetch current int 1eh pointer
+;               push    ds            ; store original 1eh pointer at stack top
+;               push    si            ; so can restore later if needed
+;
+;       Copy table to new location
 ;               mov     cl, 11        ; the parameter table is 11 bytes
 ;               rep     movsb         ; and copy the parameter block
 ;               mov     ds, ax        ; restore DS
+;
+;       Note: make desired changes to table here
+;
+;       Update int1E to new location
+;               mov     [bx+2], 0     ; set to 0:bp or 0:bp+3e as appropriate
+;               mov     word [bx], 0x7c3e ; (use 0x7c00 for DR-DOS)
 
                 sti             ; enable interrupts
+
+;       If updated floppy parameter table then must notify BIOS
+;       Otherwise a reset should not be needed here.
+;               int     0x13    ; reset drive (AX=0)
+
 ;
 ; Note: some BIOS implementations may not correctly pass drive number
 ; in DL, however we work around this in SYS.COM by NOP'ing out the use of DL
@@ -290,22 +337,21 @@ next_entry:     mov     cx, 11
                 je      ffDone
 
                 add     si, byte 0x20   ; go to next directory entry
-                jc      near boot_error ; fail if not found and si wraps
+                jc      boot_error      ; fail if not found and si wraps
                 cmp     byte [si], 0    ; if the first byte of the name is 0,
                 jnz     next_entry      ; there are no more files in the directory
 
 ffDone:
-                push    ax              ; store first cluster number
+                mov [first_cluster], ax ; store first cluster number
 
 %ifdef SETROOTDIR
                 ; copy over this portion of root dir to 0x0:500 for PC-DOS
                 ; (this may allow IBMBIO.COM to start in any directory entry)
                 lea     di, [ROOTDIR]   ; es:di = 0:0500
-                mov     cx, 0x100
+                mov     cx, 32          ; limit to this 1 entry (rest don't matter)
                 rep     movsw
 %endif
 
-
 ;       GETFATCHAIN:
 ;
 ;       Reads the FAT chain and stores it in a temporary buffer in the first
@@ -334,7 +380,7 @@ ffDone:
                 mov     ax, LOADSEG
                 mov     ds, ax                  ; ds:0 = 0x70:0 = 0:FATBUF
 
-                pop     ax                      ; restore first cluster number
+                mov ax, [first_cluster]         ; restore first cluster number
                 push    ds                      ; store LOADSEG
 
 next_clust:     stosw                           ; store cluster number
@@ -403,7 +449,30 @@ cluster_next:   lodsw                   ; AX = next cluster to read
                 mov ch, [bsMedia]       ; ch set to media id
                 mov ax, [data_start+2]  ; ax:bx set to 1st data sector
                 mov bx, [data_start]    ;
+                mov di, [first_cluster] ; set di (si:di on FAT32) to starting cluster #
+%ifdef WINBOOT
+                jmp     LOADSEG:0x0200  ; yes, pass control to kernel
+%else                
                 jmp     LOADSEG:0000    ; yes, pass control to kernel
+%endif
+
+
+; failed to boot
+boot_error:     
+call            show
+;               db      "Error! Hit a key to reboot."
+                db      "):."
+%ifdef LOOPONERR
+jmp $
+%else
+
+                ; Note: should restore floppy paramater table address at int 0x1E
+                xor     ah,ah
+                int     0x13                    ; reset floppy
+                int     0x16                    ; wait for a key
+                int     0x19                    ; reboot the machine
+%endif
+
 
 load_next:      dec     ax                      ; cluster numbers start with 2
                 dec     ax
@@ -428,22 +497,6 @@ show:           pop     si
                 jne     show                    ; until done
                 ret
 
-; failed to boot
-
-boot_error:     
-%ifdef LOOPONERR
-jmp boot_error
-%else
-call            show
-;                db      "Error! Hit a key to reboot."
-                db      "Err."
-
-                xor     ah,ah
-                int     0x13                    ; reset floppy
-                int     0x16                    ; wait for a key
-                int     0x19                    ; reboot the machine
-%endif
-
 
 ;       readDisk:       Reads a number of sectors into memory.
 ;
@@ -564,7 +617,8 @@ read_next_chained:
 
 read_ok:
                 mov     ax, word [bsBytesPerSec]  
-                shr     ax, 4                   ; adjust segment pointer by increasing
+                mov     cl, 4                   ; adjust segment pointer by increasing
+                shr     ax, cl
                 add     word [LBA_SEG], ax      ; by paragraphs read in (per sector)
 
                 add     LBA_SECTOR_0,  byte 1

docs/sys.htm

@@ -1,5 +1,5 @@
 <html>
-<title>sys</title>
+<title>sys - FreeDOS system file installer</title>
 <body>
 <h1>sys</h1>
 Copy system files and make a floppy disk or hard disk bootable.
@@ -32,6 +32,16 @@ Switches (FreeDOS specific):
   but the kernel and <a href="command.htm">command.com</a> will
   not be copied to the destination.
 
+  <b>/UPDATE</b>
+  This option is for updating (or changing) your kernel while
+  leaving your shell alone.  Updates the boot sector and copies
+  the kernel file(s) to the destination.  [Allows installing
+  latest kernel and boot sector without making a copy of your
+  current COMMAND.COM or other shell first.]  Note: for FreeDOS
+  kernel, an upgrade can also be performed by simply copying
+  KERNEL.SYS over an existing bootable one (though making a 
+  backup of your current kernel is encouraged).
+
   <b>/K <i>filename</i></b>
   Gives the <i>filename</i> of the kernel file to be copied. This option
   is only required when the kernel is not called "kernel.sys"

docs/sys.txt

@@ -1,4 +1,4 @@
-FreeDOS SYS 3.5
+FreeDOS SYS 3.6
 documentation by:
   Jeremy Davis
   Bart Oldeman
@@ -22,6 +22,7 @@ SYS [source] dest: [bootsect] [{option}]
   {option} is one or more of the following:
   /BOTH    : write to *both* the real boot sector and the image file
   /BOOTONLY: do *not* copy kernel / shell, only update boot sector or image
+  /UPDATE  : copy kernel and update boot sector (do *not* copy shell)
   /OEM     : indicates boot sector, filenames, and load segment to use
              /OEM:FD use FreeDOS compatible settings
              /OEM:DR use DR DOS 7+ compatible settings (same as /OEM)

sys/sys.c

@@ -32,7 +32,7 @@
 #define FDCONFIG        /* include support to configure FD kernel */
 /* #define DRSYS */     /* SYS for Enhanced DR-DOS (OpenDOS enhancement Project) */
 
-#define SYS_VERSION "v3.5b"
+#define SYS_VERSION "v3.6"
 #define SYS_NAME "FreeDOS System Installer "
 
 
@@ -293,25 +293,26 @@ int FDKrnConfigMain(int argc, char **argv);
 typedef struct DOSBootFiles {
   const char * kernel;   /* filename boot sector loads and chains to */
   const char * dos;      /* optional secondary file for OS */
-  WORD         loadseg;  /* segment kernel file expects to start at */
+  WORD         loadaddr; /* segment kernel file expects to start at for stdbs */
+                         /* or offset to jump into kernel for oem compat bs */
   BOOL         stdbs;    /* use FD boot sector (T) or oem compat one (F) */
   LONG         minsize;  /* smallest dos file can be and be valid, 0=existance optional */
 } DOSBootFiles;
-#define FREEDOS_FILES      { "KERNEL.SYS", NULL, 0x60, 1, 0 },
+#define FREEDOS_FILES      { "KERNEL.SYS", NULL, 0x60/*:0*/, 1, 0 },
 DOSBootFiles bootFiles[] = {
   /* Note: This order is the order OEM:AUTO uses to determine DOS flavor. */
 #ifndef DRSYS
   /* FreeDOS */   FREEDOS_FILES
 #endif
-  /* DR-DOS  */ { "DRBIO.SYS", "DRDOS.SYS", 0x70, 1, 1 },
+  /* DR-DOS  */ { "DRBIO.SYS", "DRDOS.SYS", 0x70/*:0*/, 1, 1 },
-  /* DR-DOS  */ { "IBMBIO.COM", "IBMDOS.COM", 0x70, 1, 1 },
+  /* DR-DOS  */ { "IBMBIO.COM", "IBMDOS.COM", 0x70/*:0*/, 1, 1 },
 #ifdef DRSYS
   /* FreeDOS */   FREEDOS_FILES
 #endif
 #ifdef WITHOEMCOMPATBS
-  /* PC-DOS  */ { "IBMBIO.COM", "IBMDOS.COM", 0x70, 0, 6138 },  /* pre v7 DR ??? */
+  /* PC-DOS  */ { "IBMBIO.COM", "IBMDOS.COM", /*0x70:*/0x0, 0, 6138 },  /* pre v7 DR ??? */
-  /* MS-DOS  */ { "IO.SYS", "MSDOS.SYS", 0x70, 0, 10240 },
+  /* MS-DOS  */ { "IO.SYS", "MSDOS.SYS", /*0x70:*/0x0, 0, 10240 },
-  /* W9x-DOS */ { "IO.SYS", "MSDOS.SYS", 0x70, 0, 0},
+  /* W9x-DOS */ { "IO.SYS", "MSDOS.SYS", /*0x70:*/0x0200, 0, 0 },
 #endif
 };
 #define DOSFLAVORS (sizeof(bootFiles) / sizeof(*bootFiles))
@@ -356,7 +357,8 @@ typedef struct SYSOptions {
   DOSBootFiles kernel;          /* file name(s) and relevant data for kernel */
   BYTE defBootDrive;            /* value stored in boot sector for drive, eg 0x0=A, 0x80=C */
   BOOL ignoreBIOS;              /* true to NOP out boot sector code to get drive# from BIOS */
-  BOOL copyFiles;               /* true to copy kernel files and command interpreter */
+  BOOL copyKernel;              /* true to copy kernel files */
+  BOOL copyShell;               /* true to copy command interpreter */
   BOOL writeBS;                 /* true to write boot sector to drive/partition LBA 0 */
   BYTE *bsFile;                 /* file name & path to save bs to when saving to file */
   BYTE *bsFileOrig;             /* file name & path to save original bs when backing up */
@@ -382,6 +384,7 @@ void showHelpAndExit(void)
       "  {option} is one or more of the following:\n"
       "  /BOTH    : write to *both* the real boot sector and the image file\n"
       "  /BOOTONLY: do *not* copy kernel / shell, only update boot sector or image\n"
+      "  /UPDATE  : copy kernel and update boot sector (do *not* copy shell)\n"
       "  /OEM     : indicates boot sector, filenames, and load segment to use\n"
       "             /OEM:FD use FreeDOS compatible settings\n"
       "             /OEM:EDR use Enhanced DR DOS 7+ compatible settings\n"
@@ -400,7 +403,7 @@ void showHelpAndExit(void)
       "%s CONFIG /help\n"
 #endif
       /*SYS, KERNEL.SYS/DRBIO.SYS 0x60/0x70*/
-      , pgm, bootFiles[0].kernel, bootFiles[0].loadseg
+      , pgm, bootFiles[0].kernel, bootFiles[0].loadaddr
 #ifdef FDCONFIG
       , pgm
 #endif
@@ -422,7 +425,8 @@ void initOptions(int argc, char *argv[], SYSOptions *opts)
   memset(opts, 0, sizeof(SYSOptions));
   /* set srcDrive and dstDrive after processing args */
   opts->flavor = OEM_AUTO;      /* attempt to detect DOS user wants to boot */
-  opts->copyFiles = 1;          /* actually copy the kernel and cmd interpreter to dstDrive */
+  opts->copyKernel = 1;         /* actually copy the kernel and cmd interpreter to dstDrive */
+  opts->copyShell = 1;
 
   /* cycle through processing cmd line arguments */
   for(argno = 1; argno < argc; argno++)
@@ -446,7 +450,14 @@ void initOptions(int argc, char *argv[], SYSOptions *opts)
       /* do *not* copy kernel / shell, only update boot sector or image */
       else if (memicmp(argp, "BOOTONLY", 8) == 0)
       {
-        opts->copyFiles = 0;
+        opts->copyKernel = 0;
+        opts->copyShell = 0;
+      }
+      /* copy kernel and update boot sector (do *not* copy shell) */
+      else if (memicmp(argp, "UPDATE", 8) == 0)
+      {
+        opts->copyKernel = 1;
+        opts->copyShell = 0;
       }
       /* indicates compatibility mode, fs, filenames, and load segment to use */
       else if (memicmp(argp, "OEM", 3) == 0)
@@ -499,7 +510,7 @@ void initOptions(int argc, char *argv[], SYSOptions *opts)
         }
         else if (toupper(*argp) == 'L') /* set Load segment */
         {
-          opts->kernel.loadseg = (WORD)strtol(argv[argno], NULL, 16);
+          opts->kernel.loadaddr = (WORD)strtol(argv[argno], NULL, 16);
         }
         else if (memicmp(argp, "B", 2) == 0) /* set boot drive # */
         {
@@ -673,7 +684,7 @@ void initOptions(int argc, char *argv[], SYSOptions *opts)
   /* set compatibility settings not explicitly set */
   if (!opts->kernel.kernel) opts->kernel.kernel = bootFiles[opts->flavor].kernel;
   if (!opts->kernel.dos) opts->kernel.dos = bootFiles[opts->flavor].dos;
-  if (!opts->kernel.loadseg) opts->kernel.loadseg = bootFiles[opts->flavor].loadseg;
+  if (!opts->kernel.loadaddr) opts->kernel.loadaddr = bootFiles[opts->flavor].loadaddr;
   opts->kernel.stdbs = bootFiles[opts->flavor].stdbs;
   opts->kernel.minsize = bootFiles[opts->flavor].minsize;
 
@@ -688,7 +699,7 @@ void initOptions(int argc, char *argv[], SYSOptions *opts)
 
 
   /* unless we are only setting boot sector, verify kernel file exists */
-  if (opts->copyFiles)
+  if (opts->copyKernel)
   {
     /* check kernel (primary file) 1st */
     sprintf(srcFile, "%s%s", opts->srcDrive, (opts->fnKernel)?opts->fnKernel:opts->kernel.kernel);
@@ -720,7 +731,11 @@ void initOptions(int argc, char *argv[], SYSOptions *opts)
         exit(1);
       }
     }
+  }
 
+  /* if updating or only setting bootsector then skip this check */
+  if (opts->copyShell)
+  {
     /* lastly check for command interpreter */
     sprintf(srcFile, "%s%s", opts->srcDrive, (opts->fnCmd)?opts->fnCmd:"COMMAND.COM");
     if (stat(srcFile, &fstatbuf))  /* if !exists() */
@@ -754,7 +769,7 @@ int main(int argc, char **argv)
   printf("Processing boot sector...\n");
   put_boot(&opts);
 
-  if (opts.copyFiles)
+  if (opts.copyKernel)
   {
     printf("Now copying system files...\n");
 
@@ -774,7 +789,12 @@ int main(int argc, char **argv)
         exit(1);
       } /* copy secondary file (DOS) */
     }
+  }
 
+  if (opts.copyShell)
+  {
+    printf("Copying shell (command interpreter)...\n");
+  
     /* copy command.com, 1st try source path, then try %COMSPEC% */
     sprintf(srcFile, "%s%s", opts.srcDrive, (opts.fnCmd)?opts.fnCmd:"COMMAND.COM");
     if (!copy(srcFile, opts.dstDrive, "COMMAND.COM"))
@@ -1337,6 +1357,7 @@ void put_boot(SYSOptions *opts)
   if (fs == FAT32)
   {
     bs32 = (struct bootsectortype32 *)&newboot;
+    if (!bs32->bsBackupBoot) bs32->bsBackupBoot = 0x6; /* ensure set, 6 is MS defined bs size */
     bs32->bsDriveNumber = opts->defBootDrive;
 
     /* the location of the "0060" segment portion of the far pointer
@@ -1350,7 +1371,7 @@ void put_boot(SYSOptions *opts)
     */
     if (opts->kernel.stdbs)
     {
-      ((int *)newboot)[0x78/sizeof(int)] = opts->kernel.loadseg;
+      ((int *)newboot)[0x78/sizeof(int)] = opts->kernel.loadaddr;
       bsBiosMovOff = 0x82;
     }
     else /* compatible bs */
@@ -1374,23 +1395,34 @@ void put_boot(SYSOptions *opts)
     /* the location of the "0060" segment portion of the far pointer
        in the boot sector is just before cont: in boot*.asm.
        This happens to be offset 0x78 for FAT32 and offset 0x5c for FAT16 
+       The oem boot sectors do not have/need this value for patching.
+
+       the location of the jmp address (patching from
+       EA00007000 [jmp 0x0070:0000] to EA00207000 [jmp 0x0070:0200])
+       0x11b: for fat12 oem boot sector
+       0x118: for fat16 oem boot sector
+       The standard boot sectors do not have/need this value patched.
 
        force use of value stored in bs by NOPping out mov [drive], dl
        0x66: 88h,56h,24h for fat16 and fat12 boot sectors
        0x4F: 88h,56h,24h for oem compatible fat16 and fat12 boot sectors
-
+       
        i.e. BE CAREFUL WHEN YOU CHANGE THE BOOT SECTORS !!! 
     */
     if (opts->kernel.stdbs)
     {
-      ((int *)newboot)[0x5c/sizeof(int)] = opts->kernel.loadseg;
+      /* this sets the segment we load the kernel to, default is 0x60:0 */
+      ((int *)newboot)[0x5c/sizeof(int)] = opts->kernel.loadaddr;
       bsBiosMovOff = 0x66;
     }
     else
     {
-      /* load segment hard coded to 0x70 in oem compatible boot sector */
+      /* load segment hard coded to 0x70 in oem compatible boot sector, */
-      if (opts->kernel.loadseg != 0x70)
+      /* this however changes the offset jumped to default 0x70:0       */
-        printf("%s: Warning! ignoring load segment, compat bs always uses 0x70!\n", pgm);
+      if (fs == FAT12)
+        ((int *)newboot)[0x11c/sizeof(int)] = opts->kernel.loadaddr;
+      else
+        ((int *)newboot)[0x119/sizeof(int)] = opts->kernel.loadaddr;
       bsBiosMovOff = 0x4F;
     }
   }
@@ -1443,7 +1475,10 @@ void put_boot(SYSOptions *opts)
 #ifdef DEBUG
   /* there's a zero past the kernel name in all boot sectors */
   printf("Boot sector kernel name set to %s\n", &newboot[0x1f1]);
-  printf("Boot sector load segment set to %Xh\n", opts->kernel.loadseg);
+  if (opts->kernel.stdbs)
+    printf("Boot sector kernel load segment set to %X:0h\n", opts->kernel.loadaddr);
+  else
+    printf("Boot sector kernel jmp address set to 70:%Xh\n", opts->kernel.loadaddr);
 #endif
 
 #ifdef DDEBUG
@@ -1463,6 +1498,25 @@ void put_boot(SYSOptions *opts)
       printf("Can't write new boot sector to drive %c:\n", opts->dstDrive + 'A');
       exit(1);
     }
+    
+    /* for FAT32, we need to update the backup copy as well */
+    /* Note: assuming sectors 1-5 & 7-11 (FSINFO+additional boot code)
+       are properly setup by prior format and need no modification
+       [technically freespace, etc. should be updated]
+    */
+    if (fs == FAT32)
+    {
+      bs32 = (struct bootsectortype32 *)&newboot;
+#ifdef DEBUG
+      printf("writing backup bootsector to sector %d\n", bs32->bsBackupBoot);
+#endif
+      if (MyAbsReadWrite(opts->dstDrive, 1, bs32->bsBackupBoot, newboot, 1) != 0)
+      {
+        printf("Can't write backup boot sector to drive %c:\n", opts->dstDrive + 'A');
+        exit(1);
+      }
+    }
+
   } /* if write boot sector to boot record*/
 
   if (opts->bsFile != NULL)