The oViT project represents the center point for an attempt at reverse engineering 1st Generation TiVo storage, using modern techniques and technologies. oViT's end goal is to successfully extract recorded programs from an early-2000's era TiVo hard drive, and play the extracted files back.
Because this project is currently more research project and less polished software, this README will contain all of the discovered and known information about the 1st Generation TiVo hard drive.
oViT is being developed from the data from a Sony SAT T-60 (Series 1) TiVo. An ISO created using dd is being used for reverse engineering, for convenience and to avoid undue labor on the 20 year old mechanical drive.
The cloned ISO is 40 Gigabytes large (matching the original hard drive) and contains the following data from the TiVo.
The hard drive was formatted with an Apple Partition Map in BigEndian format. Running cargo run -p ovit-tools -- partitions tivo_hdd.iso shows the following about the partition map at the start of the cloned TiVo drive:
| Partition Total | Starting Sector | Sector Size | Name | Type | Starting Data Sector | Data Sectors | Status |
|---|---|---|---|---|---|---|---|
| 13 | 1 | 63 | Apple |
Apple_partition_map |
0 | 63 | 0x000033 |
| 13 | 43009349 | 4096 | Bootstrap 1 |
Image |
0 | 4096 | 0x000033 |
| 13 | 43013445 | 4096 | Kernel 1 |
Image |
0 | 4096 | 0x000033 |
| 13 | 43017541 | 262144 | Root 1 |
Ext2 |
0 | 262144 | 0x000033 |
| 13 | 43279685 | 4096 | Bootstrap 2 |
Image |
0 | 4096 | 0x000033 |
| 13 | 43283781 | 4096 | Kernel 2 |
Image |
0 | 4096 | 0x000033 |
| 13 | 43287877 | 262144 | Root 2 |
Ext2 |
0 | 262144 | 0x000033 |
| 13 | 43550021 | 131072 | Linux swap |
Swap |
0 | 131072 | 0x000033 |
| 13 | 43681093 | 262144 | /var |
Ext2 |
0 | 262144 | 0x000033 |
| 13 | 43943237 | 1048576 | MFS application region |
MFS |
0 | 1048576 | 0x000033 |
| 13 | 46040389 | 32158361 | MFS media region |
MFS |
0 | 32158361 | 0x000133 |
| 13 | 44991813 | 1048576 | MFS application region 2 |
MFS |
0 | 1048576 | 0x000033 |
| 13 | 64 | 43009285 | MFS media region 2 |
MFS |
0 | 43009285 | 0x000133 |
At the time of writing oViT is able to serialize the following MFS data types:
- MFS Volume Header
- MFS Zones and Zone Maps
- MFS INode
- Directories
Running cargo run -p ovit-tools -- header /run/media/kepler/External/tivo_hdd.iso shows the following information from the drive's volume header:
| Variable | Value |
|---|---|
| State | 0 |
| Checksum | 2053975265 |
| Root FSID | 1 |
| First Partition Size | 1024 |
| Partition List | /dev/hda10 /dev/hda11 /dev/hda12 /dev/hda13 |
| Total Sectors | 77263872 |
| Zonemap Sector | 1121 |
| Zonemap Backup Sector | 1048574 |
| Zonemap Partition Size | 524288 |
| Next FSID | 12697810 |
Running cargo run -p ovit-tools -- zones tivo_hdd.iso shows the following about the different zones of the MFS partitions on the drive:
| Sector | Backup Sector | Zonemap Size | Next Zonemap Pointer | Backup Next Zonemap Pointer | Next Zonemap Size | Next Zonemap Partition Size | Next Zonemap Min. Allocation | Logstamp | Type | Checksum | First Sector | Last Sector | Size | Min. Allocations | Free Space | Bitmap Number |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1121 | 1048574 | 1 | 525410 | 1048565 | 9 | 32157696 | 2048 | 101141407 | INode | 881335562 | 1122 | 525409 | 524288 | 524288 | 524288 | 1 |
| 525410 | 1048565 | 9 | 525419 | 1048531 | 34 | 523072 | 8 | 104363088 | Media | 2999402420 | 1048576 | 33206271 | 32157696 | 2048 | 1122304 | 15 |
| 525419 | 1048531 | 34 | 33206272 | 34254847 | 1 | 524288 | 524288 | 104363743 | Application | 3907386156 | 525453 | 1048524 | 523072 | 8 | 304760 | 17 |
Running cargo run -p ovit-tools -- inodes tivo_hdd.iso -c 10 shows the first 10 INodes on the disk, as follows:
| FSID | Reference Count | Boot Cycles | Boot Seconds | INode | Size | Block Size | Blocks Used | Last Modified | Type | Zone | Checksum | Flags | Number of Blocks |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | 201 | 96284190 | 0 | 8 | 0 | 0 | 2011-11-01 09:31:13 UTC | Db | 2 | 874701711 | 1073741824 | 0 |
| 12654953 | 2 | 201 | 99111427 | 1 | 2624 | 0 | 0 | 2011-11-03 08:58:51 UTC | Db | 2 | 671757100 | 0 | 1 |
| 0 | 0 | 199 | 28813273 | 2 | 8 | 0 | 0 | 2011-08-10 12:52:35 UTC | Db | 2 | 24436353 | 1073741824 | 0 |
| 0 | 0 | 200 | 32039606 | 3 | 8 | 0 | 0 | 2011-08-28 02:44:29 UTC | Db | 2 | 1390534620 | 1073741824 | 0 |
| 0 | 0 | 200 | 32043960 | 4 | 8 | 0 | 0 | 2011-08-28 02:53:28 UTC | Db | 2 | 3751297821 | 1073741824 | 0 |
| 0 | 0 | 201 | 53233679 | 5 | 8 | 0 | 0 | 2011-10-02 10:59:31 UTC | Db | 2 | 3186161858 | 1073741824 | 0 |
| 0 | 0 | 201 | 66951763 | 6 | 8 | 0 | 0 | 2011-10-12 09:32:39 UTC | Db | 2 | 3391714744 | 1073741824 | 0 |
| 0 | 0 | 195 | 66562306 | 7 | 8 | 0 | 0 | 2011-03-08 09:48:00 UTC | Db | 2 | 1760814817 | 1073741824 | 0 |
| 0 | 0 | 196 | 22734645 | 8 | 2128 | 131072 | 2128 | 2011-07-04 13:20:11 UTC | Stream | 1 | 3598525128 | 0 | 0 |
| 0 | 0 | 199 | 5885156 | 9 | 8 | 0 | 0 | 2011-07-23 00:31:46 UTC | Db | 2 | 3289510782 | 1073741824 | 0 |
Below are examples of the first two files successfully viewed from the TiVo Media Filesystem using the oViT FUSE Driver:
/Server/A0003fc81:3:20:0:
/Server/AR0000a96b:4:0:0.:
oViT is implemented using Rust, with the goal of creating robust and memory-safe utilities that'll last for years to come. TiVo became a cultural touchstone in the early 2000's. Due to its cultural significance alone it should be possible to archive content from TiVo hard drives and preserve them. The tapes of previous generations are easily accessible and preservable today, the recordings from the TiVo era should be too.
oViT is build using the following libraries:
nom- for parsing Apple Partition Map data and Media File System dataclap- for creating oViT's command line interfaceschrono- for parsing time and date information present in the Media File System
-
Wikipedia entry on the TiVo Media File System
The Wikipedia entry on the TiVo Media File System provides a decent abstract of the file system format and how it was created.
-
Wikipedia entry on the Apple Partition Map
The Wikipedia entry on the Apple Partition Map provides a very good abstract of the partitioning scheme used on 1st Generation TiVo hard drives.
-
MFS Tools on the TiVo Community Forum
MFS Tools is an open source CLI utility for interacting with TiVo Hard Drives. It's primary use case is for upgrading the hard drives in a functioning TiVo unit, not extracting data from the drive of an offline TiVo hard drive. However, the source code serves a good reference.
-
TygerStripe/mfstools on GitHub
The C source code for MFS Tools available on GitHub, helpful for reference. The way MFS Tools allocates portions of the storage to C structs is incredibly helpful for understanding how to read the drive. oViT opts for data parsing over allocation, in the name of verbosity and memory safety.
-
Battling Bit Rot, Link Rot, and Chaos: Hacking an 18 Year Old TiVo Hard Drive by Kepler Sticka-Jones
This October 12, 2019 entry on my blog details how oViT came into being, and explains the project's motivation and the early thought process.
-
‘They Thought It Was Black Magic’: An Oral History of TiVo by Tom Roston
Although this article doesn't contain much technical detail about early TiVo devices, it does provide some general context to the creation of TiVo and explains some of the decisions made by the early TiVo development team. Worth a read if you are considering reverse engineering early TiVo data.
Copyright 2019-2020 Kepler Sticka-Jones. All Rights Reserved.
Note: Due to the current very unpolished state of the project, I am retaining all rights. In the future I hope to license the code under MIT, when the project becomes more polished and production ready.