image: Add offset argument

zanesterling / fatr

A FAT12 parsing and manipulation tool

MIT License

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image: Add offset argument #10

Closed kallisti5 closed 7 years ago

kallisti5 commented 7 years ago

Allows you to specify an offset to load a filesystem from.
Enables fatr to skip over partition tables into a filesystem.
Native rust mbr and gpt crates already exist to parse partition tables.
We need to figure out a better way to find the end of the filesystem. (currently length of file minus offset)

kallisti5 commented 7 years ago

This allows us to skip into a fat filesystem in a disk image. Useful when partition tables exist. The logic to find the end of the fat filesystem at the moment is based on the file size. This assumption no longer works on partitioned disks... from the FAT BIOS_Param I don't see a reliable length. Maybe two functions instead? from_file and from_file_range with a start and end ?

kallisti5 commented 7 years ago

ok. Reworked to have two file_from functions. file_from_offset accepts a length and an offset to load the FAT filesystem from.

kallisti5 commented 7 years ago

nah. Good nits. I shouldn't of made them single letter in the first place. Went with image_fn to match save function.