What are the reasons why the USB flash drive does not start

In different BIOS for USB drive (USB-HDD mode), the capacity parameters of the same USB flash drive---cylinder, head and number of sectors (CHS), identification is different (prove this can install the same version of Linux on various machines, and then insert a USB stick, using Hdparm/dev /SDA command can be found in different machines, CHS, even if the USB flash drive can be used to boot the grub, using the Geometry (hd0) command in Grub can also be seen), The partition table and the Fat disk parameter table generated by partitioning the format on a single machine are expressed in terms of the CHS of the hard drive recognized by this machine, which can cause confusion when switching to another machine because the CHS identified by another machine is different.

Fortunately, the partition table and the Fat disk parameter table also have a way of expressing relative sector numbers, which is also recorded in the partition table and the disk parameter table. This depends on which data the software uses to work, if the use of CHS, then a different machine will not work properly, if the use of LBA access to the disk is not affected---of course, the premise is that the BIOS supports the use of LBA access to the USB flash drive is extended INT13h. and XP to the FAT16 file system partition format generated MBR code and DOS versions are dependent on CHS to work, so the usual method in a machine-made boot USB drive on another machine may not be successful. The test mobile hard drive in each bios of the CHS is consistent, and the hard disk directly connected to the IDE port of CHS, so the mobile hard disk USB boot is basically no difficulty.

The current findings are indeed affected by this problem and thus affect the start-up process:

1. MBR written by Windows XP and SP1 in the Chinese version of Disk Manager partition

2. Usboot-generated MBR and boot (same as 1)

3. Install GRLDR.MBR in grub for DOS 0.41 to MBR using bootlace.com

Programs that may not be affected by this problem are (not fully tested):

1, NTLDR and then start the PE or XP environment (of course, otherwise the U disk will not be used)

2, Linux under the INSTALL-MBR program written by the MBR

3. GNU GRUB 0.95 and 0.97 and its boot code installed using the Grub-install command

4, syslinux3.36 and 3.51

5, linux2.4 kernel above, basically Linux system All programs on the FAT file system will not use CHS

8. Grub CHS 0.95 0.97 (included Stage1, stage1.5, and stage2 boot code)