[S-Record Format] SREC(4) UNIX 5.0 (03/21/84) SREC(4) An S-record file consists of a sequence of specially formatted ASCII character strings. An S-record will be less than or equal to 78 bytes in length. The order of S-records within a file is of no significance and no particular order may be assumed. The general format of an S-record follow: +------------------//-------------------//-----------------------+ | type | count | address | data | checksum | +------------------//-------------------//-----------------------+ type A char[2] field. These characters describe the type of record (S0, S1, S2, S3, S5, S7, S8, or S9). count A char[2] field. These characters when paired and interpreted as a hexadecimal value, display the count of remaining character pairs in the record. address A char[4,6, or 8] field. These characters grouped and interpreted as a hexadecimal value, display the address at which the data field is to be loaded into memory. The length of the field depends on the number of bytes necessary to hold the address. A 2-byte address uses 4 characters, a 3-byte address uses 6 characters, and a 4-byte address uses 8 characters. data A char [0-64] field. These characters when paired and interpreted as hexadecimal values represent the memory loadable data or descriptive information. checksum A char[2] field. These characters when paired and interpreted as a hexadecimal value display the least significant byte of the ones complement of the sum of the byte values represented by the pairs of characters making up the count, the address, and the data fields. Each record is terminated with a line feed. If any additional or different record terminator(s) or delay characters are needed during transmission to the target system it is the responsibility of the transmitting program to provide them. S0 Record The type of record is 'S0' (0x5330). The address field is unused and will be filled with zeros (0x0000). The header information within the data field is divided into the following subfields. mname is char[20] and is the module name. ver is char[2] and is the version number. rev is char[2] and is the revision number. description is char[0-36] and is a text comment. Each of the subfields is composed of ASCII bytes whose associated characters, when paired, represent one byte hexadecimal values in the case of the version and revision numbers, or represent the hexadecimal values of the ASCII characters comprising the module name and description. S1 Record The type of record field is 'S1' (0x5331). The address field is interpreted as a 2-byte address. The data field is composed of memory loadable data. S2 Record The type of record field is 'S2' (0x5332). The address field is interpreted as a 3-byte address. The data field is composed of memory loadable data. S3 Record The type of record field is 'S3' (0x5333). The address field is interpreted as a 4-byte address. The data field is composed of memory loadable data. S5 Record The type of record field is 'S5' (0x5335). The address field is interpreted as a 2-byte value and contains the count of S1, S2, and S3 records previously transmitted. There is no data field. S7 Record The type of record field is 'S7' (0x5337). The address field contains the starting execution address and is interpreted as 4-byte address. There is no data field. S8 Record The type of record field is 'S8' (0x5338). The address field contains the starting execution address and is interpreted as 3-byte address. There is no data field. S9 Record The type of record field is 'S9' (0x5339). The address field contains the starting execution address and is interpreted as 2-byte address. There is no data field. EXAMPLE Shown below is a typical S-record format file. S00600004844521B S1130000285F245F2212226A000424290008237C2A S11300100002000800082629001853812341001813 S113002041E900084E42234300182342000824A952 S107003000144ED492 S5030004F8 S9030000FC The file consists of one S0 record, four S1 records, one S5 record and an S9 record. The S0 record is comprised as follows: S0 S-record type S0, indicating it is a header record. 06 Hexadecimal 06 (decimal 6), indicating that six character pairs (or ASCII bytes) follow. 00 00 Four character 2-byte address field, zeroes in this example. 48 ASCII H, D, and R - "HDR". 1B The checksum. The first S1 record is comprised as follows: S1 S-record type S1, indicating it is a data record to be loaded at a 2-byte address. 13 Hexadecimal 13 (decimal 19), indicating that nineteen character pairs, representing a 2 byte address, 16 bytes of binary data, and a 1 byte checksum, follow. 00 00 Four character 2-byte address field; hexidecimal address 0x0000, where the data which follows is to be loaded. 28 5F 24 5F 22 12 22 6A 00 04 24 29 00 08 23 7C Sixteen character pairs representing the actual binary data. 2A The checksum. The second and third S1 records each contain 0x13 (19) character pairs and are ended with checksums of 13 and 52, respectively. The fourth S1 record contains 07 character pairs and has a checksum of 92. The S5 record is comprised as follows: S5 S-record type S5, indicating it is a count record indicating the number of S1 records. 03 Hexadecimal 03 (decimal 3), indicating that three character pairs follow. 00 04 Hexadecimal 0004 (decimal 4), indicating that there are four data records previous to this record. F8 The checksum. The S9 record is comprised as follows: S9 S-record type S9, indicating it is a termination record. 03 Hexadecimal 03 (decimal 3), indicating that three character pairs follow. 00 00 The address field, hexadecimal 0 (decimal 0) indicating the starting execution address. FC The checksum. [Intel Hex ASCII Format] Intel HEX-ASCII format takes the form: +----------------------------------- Start Character | | +-------------------------------- Byte Count | | (# of data bytes) | | | | +-------------------------- Address of first data. | | | | | | +-------------------- Record Type (00 data, | | | | 01 end of record) | | | | | | | | +------------ Data Bytes | | | | | | | | | | +---- Checksum | | | | | | | / \ / \ / \ / \ / \ : B C A A A A T T H H ... H H C C An examples: :10000000DB00E60F5F1600211100197ED300C3004C :1000100000000101030307070F0F1F1F3F3F7F7FF2 :01002000FFE0 :00000001FF This information comes from _Microprocessors and Programmed Logic_, Second Edition, Kenneth L. Short, 1987, Prentice-Hall, ISBN 0-13-580606-2. Provisions have been made for data spaces larger than 64 kBytes. The above reference does not discuss them. I suspect there is a start of segment type record, but I do not know how it is implemented. Here also a description from the Buffalo monitor manual: Date: 19970915 From: Glen Wiley To: Mot-68HC11-Apps@freeware.mcu.motsps.com Subject: Re: S19 format The following is taken from the buffalo monitor manual: APPENDIX A S-RECORD INFORMATION INTRODUCTION The Motorola S-record format was devised for the purpose of encoding programs or data files in a printable format for transportation between computer systems. This transportation process can therefore be monitored and the S-records can be easily edited. S-RECORD CONTENT When observed, S-records are essentially character strings made of several fields which identify the record type, record length, memory address, code/data, and checksum. Each byte of binary data is encoded as a 2-character hexadecimal number: the first character representing the high-order 4 bits, and the second the low-order 4 bits of the byte. Five fields which compromise an S-record are shown below: TYPE RECORD LENGTH ADDRESS CODE/DATA CHECKSUM where the fields are composed as follows: PRINTABLE FIELD CHARACTERS CONTENTS Type 2 S-record type - S0, S1, etc. Record 2 Character pair count in the record, length excluding the type and record length. Address 4,6, 2-, 3-, or 4-byte address at which or 8 the data field is to be loaded into memory. Code/data 0-2n From 0 to n bytes of executable code, memory loadable data, or descriptive information. For compatibility with teletypewriters, some programs may limit the number of bytes to as few as 28 (56 printable characters in the S- record. Checksum 2 Least significant byte of the one's complement of the sum of the values represented by the pairs of characters making up the record length, address, and the code/data fields. Each record may be terminated with a CR/LF/NULL. Additionally, an S- record may have an initial field to accommodate other data such as line numbers generated by some time-sharing systems. Accuracy of transmission is ensured by the record length (byte count) and checksum fields. S-RECORD TYPES Eight types of S-records have been defined to accommodate the several needs of the encoding, transportation, and decoding functions. The various Motorola upload, download, and other record transportation control programs, as well as cross assemblers, linkers, and other file- creating or debugging programs, utilize only those S-records which serve the purpose of the program. for specific information on which S-records are supported by a particular program, the user manual for that program must be consulted. NOTE The EVB monitor supports only the S1 and S9 records. All data before the first S1 record is ignored. Thereafter, all records must be S1 type until the S9 record terminates data transfer. An S-record format may contain the following record types: S0 Header record for each block of S-records. The code/data field may contain any descriptive information identifying the following block of S-records. The address field is normally zeroes. S1 Code/data record and the 2-byte address at which the code/data is to reside. S2-S8 Termination record for a block of S1 records. Address fields may optionally contain the 2-byte address of the instruction to which control is to be passed. If not specified, the first entry point specification encountered in the input will be used. There is no code/data field. Only one termination record is used for each block of S-records. Normally, only one header record is used, although it is possible for multiple header records to occur. S-RECORD CREATION S-record format programs ma be produce by several dump utilities, debuggers, or several cross assemblers or cross linkers. Several programs are available for downloading a file in S-record format from a host system to an 8-bit or 16-bit microprocessor-based system. S-RECORD EXAMPLE Shown below is a typical S-record format, as printed or displayed: S00600004844521B S1130000285F245F2212226A000424290008237C2A S11300100002000800082629001853812341001813 S113002041E900084E42234300182342000824A952 S107003000144ED492 S9030000FC The above format consists of an S0 header record, four S1 code/data records, and an S9 termination record. The S0 header record is comprised of the following character pairs: S0 S-record type S0, indicating a header record. 06 Hexadecimal 06 (decimal 06), indicating six character pairs (or ASCII bytes) follow. 00 Four-character 2-byte address field, zeroes. 00 48 44 ASCII H, D, and R - "HDR". 52 1B Checksum of SO record. The first S1 code/data record is explained as follows: S1 S-record type S1, indicating a code/data record to be loaded/verified at a 2-byte address. 13 Hexadecimal 13 (decimal 19), indicating 19 character pairs, representing 19 bytes of binary data, follow. 00 Four-character 2-byte address field; hexadecimal address 0000, 00 indicates location where the following data is to be loaded. The next 16 character pairs are the ASCII bytes of the actual program code/data. In this assembly language example, the hexadecimal opcodes of the program are written in sequence in the code/data fields of the S1 records; OPCODE INSTRUCTION 28 5F BHCC $0161 24 5F BCC $0163 22 12 BHI $0118 22 6A BHI $0172 00 04 24 BRSET 0,$04,$012F 29 00 BHCS $010D 08 23 7C BRSET 4,$23,$018C . (Balance of this code is continued in the code/data fields . of the remaining S1 records, and stored in memory location . 0010, etc..) 2A Checksum of the first S1 record. The second and third S1 code/data records each also contain $13 (19) character pairs and are ended with checksums 13 and 51, respectively. The fourth S1 code/data record contains 07 character paris and has a checksum of 92. The S9 termination record is explained as follows: S9 S-record type S9, indicating a termination record. 03 Hexadecimal 03, indicating three character pairs (3 bytes) follow. 00 Four-character 2-byte address field, zeroes. 00 FC Checksum of S9 record. Each printable character in an S-record is encoded in hexadecimal (ASCII in this example) representation of the binary bits which are actually transmitted. For example, the first S1 record above is sent as shown below. type length address code/data checksum S 1 1 3 0 0 0 0 2 8 5 F 2 A 53 31 31 33 30 30 30 30 32 38 35 46 32 41 -- Glen Wiley Senior Developer, CSSD - AT&T UCS