srec

MIPS处理器的bootloader,龙芯就是用的修改过的PMON2

	Motorola S-Record Format
	Motorola S-Record Format

Motorola S-records are an industry-standard format for transmitting 
binary files to target systems and PROM programmers. LSI Logic have 
extended this standard to include an S4-record containing an address 
and a symbol. 

The extended S-record standard is as follows:

S<type><length><address><data....><checksum>
S4<length><address><name>,<checksum>

Where:

 type
	is the record type. Where:
	
	0starting record (optional)
	1data record with 16-bit address
	2data record with 24-bit address
	3data record with 32-bit address
	4symbol record (LSI extension)
	5number of data records in preceeding block
	6unused
	7ending record for S3 records
	8ending record for S2 records
	9ending record for S1 records
	
length
	is two hex characters. This defines the length of the record
	in bytes (not characters). It includes the address field, the data
	field, and the checksum field.
	
address
	 is 4, 6, or 8 characters. Corresponding to a 16-, 24-, or
	32-bit address. The address field for S4 records is always
	32 bits.
	
data
	Are the data bytes. Each pair of hex characters represent
	one byte in memory.
name
	Is the symbol name. The symbol is terminated by a ','.
checksum
	Is the one's complement of the 8-bit checksum.

Example

S0030000FC
.
.
S325000004403C0880018D08DD900000000011000026000000003C0880012508DC50C50000B401
S32500000460C50100B8C50200BCC50300C0C50400C4C50500C8C50600CCC50700D0C50800D4FA
S32500000480C50900D8C50A00DCC50B00E0C50C00E4C50D00E8C50E00ECC50F00F0C51000F49A
S325000004A0C51100F8C51200FCC5130100C5140104C5150108C516010CC5170110C518011434
.
.
S70500000000FA

The S0 record starts the file. The S3 records contain the data. 
The S7 record contains the entry address and terminates the download.

Generating S-record files

The PMON source package contains two mechanisms for generating
S-record files.