Syslinux - Oct 2008 - Linux syslinux-3.72 does not update boot block for SD devices

Hi all. I am new to the list. I am trying to make a SD flash bootable.  
I have a MSI Wind netbook running Fedora 9 with a built-in card reader  
that detects the SD flash properly. However, when I run syslinux, it  
does not update the boot block. I also tried using a SD -> USB  
adapter, but I get the same behavior. Fedora 9 uses an older syslinux  
3.61, but I also tried the latest 3.72 with no luck.

NOTE: I downloaded the Windows 3.72 version of syslinux and I was able  
to successfully create a bootable SD flash under Windows XP. Here are  
the details:

Multi-card reader

scsi 4:0:0:0: Direct-Access     Generic- Multi-Card       1.00 PQ: 0  
ANSI: 0 CCS
sd 4:0:0:0: [sdb] Attached SCSI removable disk
sd 4:0:0:0: Attached scsi generic sg1 type 0

SanDisk 1G micro SD with SD adapter

sd 4:0:0:0: [sdb] 1984000 512-byte hardware sectors (1016 MB)
sd 4:0:0:0: [sdb] Write Protect is off
sd 4:0:0:0: [sdb] Mode Sense: 03 00 00 00
sd 4:0:0:0: [sdb] Assuming drive cache: write through
sd 4:0:0:0: [sdb] 1984000 512-byte hardware sectors (1016 MB)
sd 4:0:0:0: [sdb] Write Protect is off
sd 4:0:0:0: [sdb] Mode Sense: 03 00 00 00
sd 4:0:0:0: [sdb] Assuming drive cache: write through
  sdb: sdb1

$ fdisk -l /dev/sdb

Disk /dev/sdb: 1015 MB, 1015808000 bytes
32 heads, 61 sectors/track, 1016 cylinders
Units = cylinders of 1952 * 512 = 999424 bytes
Disk identifier: 0x3ab5b3b6

    Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1        1016      991585+   b  W95 FAT32

Dump of MBR:

Device: /dev/sdb
0x000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
...
0x1B0: 00 00 00 00 00 00 00 00 B6 B3 B5 3A 00 00 80 01
0x1C0: 01 00 0B 1F FD F7 3D 00 00 00 C3 42 1E 00 00 00
0x1D0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x1E0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x1F0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 AA

I tried running the following:

syslinux /dev/sdb1
syslinux -s /dev/sdb1
syslinux -sf /dev/sdb1

The ldlinux.sys gets created, but it does not update the MBR. I am  
able to make a bootable USB thumbdrive just by running 'syslinux /dev/ 
sdb1' and I was expecting the same behavior on the SD flash.

If I run the command from Windows, it does update the MBR. I ran:

syslinux -m -a e:

The MBR changed and the SD flash is now bootable.

Device: /dev/sdb
0x000: FA 31 C0 8E D8 8E D0 BC 00 7C 89 E6 06 57 52 8E
0x010: C0 FB FC BF 00 06 B9 00 01 F3 A5 EA 20 06 00 00
0x020: 52 B4 41 BB AA 55 31 C9 30 F6 F9 CD 13 72 13 81
0x030: FB 55 AA 75 0D D1 E9 73 09 66 C7 06 8D 06 B4 42
0x040: EB 15 5A B4 08 CD 13 83 E1 3F 51 0F B6 C6 40 F7
0x050: E1 52 50 66 31 C0 66 99 E8 66 00 E8 21 01 4D 69
0x060: 73 73 69 6E 67 20 6F 70 65 72 61 74 69 6E 67 20
0x070: 73 79 73 74 65 6D 2E 0D 0A 66 60 66 31 D2 BB 00
0x080: 7C 66 52 66 50 06 53 6A 01 6A 10 89 E6 66 F7 36
0x090: F4 7B C0 E4 06 88 E1 88 C5 92 F6 36 F8 7B 88 C6
0x0A0: 08 E1 41 B8 01 02 8A 16 FA 7B CD 13 8D 64 10 66
0x0B0: 61 C3 E8 C4 FF BE BE 7D BF BE 07 B9 20 00 F3 A5
0x0C0: C3 66 60 89 E5 BB BE 07 B9 04 00 31 C0 53 51 F6
0x0D0: 07 80 74 03 40 89 DE 83 C3 10 E2 F3 48 74 5B 79
0x0E0: 39 59 5B 8A 47 04 3C 0F 74 06 24 7F 3C 05 75 22
0x0F0: 66 8B 47 08 66 8B 56 14 66 01 D0 66 21 D2 75 03
0x100: 66 89 C2 E8 AC FF 72 03 E8 B6 FF 66 8B 46 1C E8
0x110: A0 FF 83 C3 10 E2 CC 66 61 C3 E8 62 00 4D 75 6C
0x120: 74 69 70 6C 65 20 61 63 74 69 76 65 20 70 61 72
0x130: 74 69 74 69 6F 6E 73 2E 0D 0A 66 8B 44 08 66 03
0x140: 46 1C 66 89 44 08 E8 30 FF 72 13 81 3E FE 7D 55
0x150: AA 0F 85 06 FF BC FA 7B 5A 5F 07 FA FF E4 E8 1E
0x160: 00 4F 70 65 72 61 74 69 6E 67 20 73 79 73 74 65
0x170: 6D 20 6C 6F 61 64 20 65 72 72 6F 72 2E 0D 0A 5E
0x180: AC B4 0E 8A 3E 62 04 B3 07 CD 10 3C 0A 75 F1 CD
0x190: 18 F4 EB FD 00 00 00 00 00 00 00 00 00 00 00 00
0x1A0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x1B0: 00 00 00 00 00 00 00 00 B6 B3 B5 3A 00 00 80 01
0x1C0: 01 00 0B 1F FD F7 3D 00 00 00 C3 42 1E 00 00 00
0x1D0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x1E0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x1F0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 AA

Is there another step I need to do to get syslinux under linux to  
work? Any help greatly appreciated. Thanks in advance.
--
Jim

Jim Fridlund wrote:
> 
> The ldlinux.sys gets created, but it does not update the MBR. I am  
> able to make a bootable USB thumbdrive just by running 'syslinux /dev/ 
> sdb1' and I was expecting the same behavior on the SD flash.
> 
> If I run the command from Windows, it does update the MBR. I ran:
> 
> syslinux -m -a e:
> 
> The MBR changed and the SD flash is now bootable.
> 
> Is there another step I need to do to get syslinux under linux to  
> work? Any help greatly appreciated. Thanks in advance.
dd if=/usr/lib/syslinux/mbr.bin of=/dev/sdb bs=440 count=1

The reason this isn't automatic is that this is sometimes not possible 
under Linux.

	-hpa

On Oct 25, 2008, at 4:40 PM, H. Peter Anvin wrote:
> Jim Fridlund wrote:
>> I see what you mean. I stepped through it with the debugger and I see
>> syslinux trying to write to the mbr by invoking xpwrite() function
>> which calls the pwrite() system call. The system call returned 512
>> bytes, but reading back still showed the old values. Again, thanks  
>> for
>> the help!
>
> What you saw was writing the boot sector, not the MBR.
>
> 	-hpa
Yes, thanks for clarifying and for all your help. syslinux rocks! :)
--
Jim