ScanTool STN Bootloader - Manual (Page 8)

STN Bootloader
Table 8 – Firmware Upload Commands
Command Name Description
30 StartUpload Start firmware image upload
31 SendChunk Send the next firmware image chunk
StartUpload
Start firmware image upload. Every firmware image
upload must be preceded by a StartUpload command.
The StartUpload command packet has the following
format:
<0x30><0x04>[]
Table 9 details the data field format of the
StartUpload command.
Table 9 – StartUpload Command Format
Field
Length
(bytes)
Description
3 Firmware image size
1
Mode. Must be set to
0x01
The response to StartUpload command is a big-
endian 16-bit integer specifying the maximum chunk
size that can be accepted by the bootloader (data
length = 2).
SendChunk
Send the next firmware image chunk. Firmware
chunk length must be a multiple of 16 bytes, and
cannot exceed the maximum chunk size returned by
the StartUpload command. The chunk size can be
varied to achieve the optimum balance between
firmware upload speed, progress granularity, and the
speed of error recovery.
The SendChunk command packet has the following
format:
<0x31>[]
Table 10 details SendChunk command data field
format.
Table 10 – SendChunk Command Format
Field
Length
(bytes)
Description
2 Chunk number
variable
Firmware image
chunk data
Chunk number is a sequential number assigned to
each chunk. It must be set to 0 for the first chunk and
then incremented by one for each subsequent chunk.
The response to SendChunk command contains
the 16-bit chunk number (data length = 2).
6.0 Firmware Update Procedure
Basic firmware update steps are as follows:
1. Load firmware file header into memory
2. Start bootloader session (Connect)
3. Verify bootloader version (GetVersion).
Proceed only if the major version is 2.
4. Upload each firmware image (see
Appendix A: Firmware File Format for
details):
a. Send StartUpload command
b. Send firmware image using
SendChunk commands until all
bytes of the firmware image have
been transmitted
5. Send GetFWStatus command to verify that
the application firmware was successfully
uploaded
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