ScanTool STN Bootloader - Manual (Page 6)

STN Bootloader
CRC
The bootloader responds with this error when the
received packet fails the CRC check. To recover from
this error, resend the packet.
Packet Too Long
Whenever the size of the bootloader’s internal
buffer is exceeded, it will stop receiving the command
and wait for the character; after it receives the
, the bootloader will respond with the Packet
Too Long error.
When properly formatted, none of the commands
with fixed data length will generate this error. However,
the SendChunk command accepts a variable data
length parameter, and may generate this error if the
data length exceeds the maximum chunk size
supported by the bootloader. See StartUpload
command description for more information.
4.6.2.2 Command Validation Errors
After the bootloader receives a packet and verifies
the CRC, it proceeds to validate the command. The
following two errors may be generated for any
command received by the bootloader:
Unknown Command
field of a packet received by the
bootloader does not match any of the supported
commands.
Command Format
This error will be generated by an incorrect
formatting of the field. This can happen if the
data length is incorrect, or the data values are outside
of the supported range.
4.6.2.3 Firmware Upload Errors
Firmware upload errors can occur at any point
during the firmware upload sequence. The two
commands that can generate these errors are
StartUpload and SendChunk.
Sequence
This error is returned when a firmware upload
sequence error is detected. Conditions that can cause
this error are:
• SendChunk command received before
StartUpload command
• Chunk number is out of sequence
• The number of bytes received by the bootloader
exceeds the number specified by the
field of the StartUpload command
Authentication
This error will be returned if the host software
attempts to upload a firmware image for the wrong
device. It can also be caused by a corrupted firmware
image.
If an attempt is made to upload an invalid firmware
image, most of the time this will be detected within the
first few packets and the old firmware will remain intact.
Programming
This error will be returned if the bootloader
encounters any errors while attempting to program the
uploaded firmware. To attempt a recovery, reset the
device and try uploading the firmware again.
Validation
This error is similar to the Programming error.
However, it has a special meaning for firmware images
of the Validation type. See section 6.0 “Firmware
Update Procedure” for more information.
5.0 Bootloader Commands
5.1 Control Commands
Control commands are used for establishing and
terminating the bootloader session and to aid in error
recovery. All control commands have their data length
field set to 0x0000. Table 6 summarizes control
commands supported by the current version of STN
Bootloader.
Table 6 – Control Commands
Command Name Description
03 Connect Start bootloader session
02 Reset Reset device
01 ResendLast Resend last response
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