mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-11-26 09:28:13 +00:00
60 lines
2.5 KiB
Markdown
60 lines
2.5 KiB
Markdown
#TREZOR Core Bootloader
|
|
|
|
All multibyte integer values are little endian!
|
|
|
|
##Firmware File Format
|
|
|
|
TREZOR Core firmware file consists of 3 parts:
|
|
|
|
1. vendor header
|
|
2. firmware header
|
|
3. firmware code
|
|
|
|
Hash function used is SHA-256 and signature system is Ed25519 (allows combining signatures by multiple keys into one).
|
|
|
|
###Vendor Header
|
|
|
|
Total length of vendor header is 82 + 32 * (number of pubkeys) + (length of vendor string) + (length of vendor image) bytes rounded up to the closest multiply of 256 bytes.
|
|
|
|
| offset | length | name | description |
|
|
|-------:|-------:|------|-------------|
|
|
| 0x0000 | 4 | magic | firmware magic `TRZV` |
|
|
| 0x0004 | 4 | hlen | length of the vendor header |
|
|
| 0x0008 | 4 | expiry | valid until timestamp |
|
|
| 0x000C | 1 | vsig_m | number of signatures needed to run the firmware from this vendor |
|
|
| 0x000D | 1 | vsig_n | number of pubkeys vendor wants to use for signing |
|
|
| 0x000E | 2 | reserved | not used yet |
|
|
| 0x0010 | 32 | vpub1 | vendor pubkey 1 |
|
|
| ... | ... | ... | ... |
|
|
| ? | 32 | vpubn | vendor pubkey n |
|
|
| ? | 1 | vstr_len | vendor string length |
|
|
| ? | ? | vstr | vendor string |
|
|
| ? | ? | vimg | vendor image (in [TOIf format](toif.md)) |
|
|
| ? | 1 | slsigidx | SatoshiLabs signature indexes (bitmap) |
|
|
| ? | 64 | slsig | SatoshiLabs signature |
|
|
|
|
###Firmware Header
|
|
|
|
Total length of firmware header is 256 bytes.
|
|
|
|
| offset | length | name | description |
|
|
|-------:|-------:|------|-------------|
|
|
| 0x0000 | 4 | magic | firmware magic `TRZF` |
|
|
| 0x0004 | 4 | hlen | length of the firmware header |
|
|
| 0x0008 | 4 | expiry | valid until timestamp |
|
|
| 0x000C | 4 | codelen | length of the firmware code |
|
|
| 0x0010 | 1 | vmajor | version (major) |
|
|
| 0x0011 | 1 | vminor | version (minor) |
|
|
| 0x0012 | 1 | vpatch | version (patch) |
|
|
| 0x0013 | 1 | vbuild | version (build) |
|
|
| 0x0014 | 1 | vndsigidx | vendor signature indexes (bitmap) |
|
|
| 0x0015 | 64 | vndsig | vendor signature |
|
|
| 0x0079 | 135 | reserved | not used yet |
|
|
|
|
##Various ideas
|
|
|
|
* Bootloader should be able to read vendor+firmware header and send info about FW to client in features message.
|
|
* Bootloader should not try to run firmware if there is not any.
|
|
* Storage wiping rule: Don't erase storage when old FW and new FW are signed using the same key set. Otherwise erase.
|
|
* Bootloader should send error to client when firmware update fails and allow client to try one more time. This prevents storage area erasure by accident.
|