NAME
srec_intel16 - Intel Hexadecimal 16‐bit file format specification
DESCRIPTION
This format is also known as the INHX16 format.
This document describes the hexadecimal object file format for 16‐bit
microprocessors.
This format is very similar to the srec_intel(5) format, except that
the addresses are word addresses. The count field is a word count.
The hexadecimal representation of binary is coded in ASCII alphanumeric
characters. For example, the 8‐bit binary value 0011‐1111 is 3F in
hexadecimal. To code this in ASCII, one 8‐bit byte containing the
ASCII code for the character ’3’ (0011‐0011 or 0x33) and one 8‐bit byte
containing the) ASCII code for the character ’F’ (0100‐0110 or 0x46)
are required. For each byte value, the high‐order hexadecimal digit is
always the first digit of the pair of hexadecimal digits. This
representation (ASCII hexadecimal) requires twice as many bytes as the
binary representation.
A hexadecimal object file is blocked into records, each of which
contains the record type, length, memory load address and checksum in
addition to the data. There are currently six (6) different types of
records that are defined, not all combinations of these records are
meaningful, however. The record are:
· Data Record
· End of File Record
· Extended Segment Address Record
· Start Segment Address Record
· Extended Linear Address Record
· Start Linear Address Record
General Record Format
+-------+--------+--------+--------+--------+--------+
|Record | Record | Load | Record | Data | Check |
|Mark | Length | Offset | Type | | sum |
+-------+--------+--------+--------+--------+--------+
Record Mark.
Each record begins with a Record Mark field containing 0x3A,
the ASCII code for the colon (“:”) character.
Record Length
Each record has a Record Length field which specifies the
number of 16‐bit words of information or data which follows the
Record Type field of the record. This field is one byte,
represented as two hexadecimal characters. The maximum value
of the Record Length field is hexadecimal ’FF’ or 255.
Load Offset
Each record has a Load Offset field which specifies the 16‐bit
starting load offset of the data words, therefore this field is
only used for Data Records (if the words are loaded as bytes,
the address needs to be doubled). In other records where this
field is not used, it should be coded as four ASCII zero
characters (“0000” or 0x30303030). This field one 16‐bit word,
represented as four hexadecimal characters.
Record Type
Each record has a Record Type field which specifies the record
type of this record. The Record Type field is used to
interpret the remaining information within the record. This
field is one byte, represented as two hexadecimal characters.
The encoding for all the current record types are:
0 Data Record
1 End of File Record
5 Execution Start Address Record
Data Each record has a variable length Data field, it consists of
zero or more 16‐bit words encoded as set of 4 hexadecimal
digits, most significant digit first. The interpretation of
this field depends on the Record Type field.
Checksum
Each record ends with a Checksum field that contains the ASCII
hexadecimal representation of the two’s complement of the
8‐bit bytes that result from converting each pair of ASCII
hexadecimal digits to one byte of binary, from and including
the Record Length field to and including the last byte of the
Data field. Therefore, the sum of all the ASCII pairs in a
record after converting to binary, from the Record Length field
to and including the Checksum field, is zero.
Data Record
(8‐, 16‐ or 32‐bit formats)
+-------+--------+--------+--------+--------+--------+
|Record | Record | Load | Record | Data | Check |
|Mark | Length | Offset | Type | | sum |
|(“:”) | | | | | |
+-------+--------+--------+--------+--------+--------+
The Data Record provides a set of hexadecimal digits that represent the
ASCII code for data bytes that make up a portion of a memory image.
The contents of the individual fields within the record are:
Record Mark
This field contains 0x3A, the hexadecimal encoding of the ASCII
colon (“:”) character.
Record Length
The field contains two ASCII hexadecimal digits that specify
the number of 16‐bit data words in the record. The maximum
value is 255 decimal.
Load Offset
This field contains four ASCII hexadecimal digits representing
the word address at which the first word of the data is to be
placed. (For an exquivalent bytes address, double it.)
Record Type
This field contains 0x3030, the hexadecimal encoding of the
ASCII character “00”, which specifies the record type to be a
Data Record.
Data This field contains sets of four ASCII hexadecimal digits, one
set for each 16‐bit data word, most significant digit first.
Checksum
This field contains the check sum on the Record Length, Load
Offset, Record Type, and Data fields.
Execution Start Address Record
+-------+--------+--------+--------+--------+--------+
|Record | Record | Load | Record | EIP (4 | Check |
|Mark | Length | Offset | Type | bytes) | sum |
|(“:”) | (4) | (0) | (5) | | |
+-------+--------+--------+--------+--------+--------+
The Execution Start Address Record is used to specify the execution
start address for the object file. This is where the loader is to jump
to begin execution once the hex load is complete.
The Execution Start Address Record can appear anywhere in a hexadecimal
object file. If such a record is not present in a hexadecimal object
file, a loader is free to assign a default execution start address.
The contents of the individual fields within the record are:
Record mark
This field contains 0x3A, the hexadecimal encoding of the ASCII
colon (“:”) character.
Record length
The field contains 0x3032, the hexadecimal encoding of the
ASCII characters “02”, which is the length, in bytes, of the
EIP register content within this record.
Load Offset
This field contains 0x30303030, the hexadecimal encoding of the
ASCII characters “0000”, since this field is not used for this
record.
Record Type
This field contains 0x3035, the hexadecimal encoding of the
ASCII character “05”, which specifies the record type to be a
Start Address Record.
EIP This field contains eight ASCII hexadecimal digits that specify
the address. The field is encoded big‐endian (most significant
digit first).
Checksum
This field contains the check sum on the Record length, Load
Offset, Record Type, and EIP fields.
End of File Record
This shall be the last record in the file.
+-------+--------+--------+--------+--------+
|Record | Record | Load | Record | Check |
|Mark | Length | Offset | Type | sum |
|(“:”) | (0) | (0) | (1) | (0xFF) |
+-------+--------+--------+--------+--------+
The End of File Record specifies the end of the hexadecimal object
file.
The contents of the individual fields within the record are:
Record mark
This field contains 0x3A, the hexadecimal encoding of the ASCII
colon (“:”) character.
Record Length
The field contains 0x3030, the hexadecimal encoding of the
ASCII characters “00”. Since this record does not contain any
Data bytes, the length is zero.
Load Offset
This field contains 0x30303030, the hexadecimal encoding of the
ASCII characters “0000”, since this field is not used for this
record.
Record Type
This field contains 0x3031, the hexadecimal encoding of the
ASCII character “01”, which specifies the record type to be an
End of File Record.
Checksum
This field contains the check sum an the Record Length, Load
Offset, and Record Type fields. Since all the fields are
static, the check sum can also be calculated statically, and
the value is 0x4646, the hexadecimal encoding of the ASCII
characters “FF”.
Size Multiplier
In general, binary data will expand in sized by approximately 2.3 times
when represented with this format.
EXAMPLE
Here is an example INHX16 file. It contains the data “Hello, World” to
be loaded at address 0.
:0700000065486C6C2C6F5720726F646CFF0AA8
:00000001FF
COPYRIGHT
srec_cat version 1.55
Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
2007, 2008, 2009, 2010 Peter Miller
The srec_cat program comes with ABSOLUTELY NO WARRANTY; for details use
the ’srec_cat -VERSion License’ command. This is free software and you
are welcome to redistribute it under certain conditions; for details
use the ’srec_cat -VERSion License’ command.
AUTHOR
Peter Miller E‐Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/