I am using the Bochs Emulator running on an Android host system. My Android filesystem is mounted as a Bochs "vvfat" partition. Now, the way in which Bochs generates the CHS values for this partition is described in the documentation as follows:
When using the autodetection feature, the CHS values 1024/16/63 (Qemu defaults) are used. To use an MBR image file from a real disk it must be named vvfat_mbr.bin and placed in the specified directory. Bochs uses the geometry and file system type from this file and doesn't show it on the virtual disk. When using the MBR from image file only the first partition is used and it must be of type FAT16 or FAT32.
The default values as specified actually make for a 504MB disk (with 512 bytes per sector). What I want to do is generate an MBR binary that allows me to write much larger files to the disk, of a few gigabytes in size. As far as I know, Bochs does not allow you to just specify the CHS directly, it only allows you to read them from the MBR binary.
What tools can I use to generate this MBR file? Preferably for Windows, but also for Linux would be possible too. (I would doubt such tools would be available for Android, but I have both Windows and Linux guest OSs within my Bochs emulator. I can just generate the file in a guest OS and copy it to the host system because it is only an MBR and therefore will be small enough to fit inside my existing vvfat partition.)