TRASM (Type-based Relocatable ASseMbly), as the number suggests, is an assembler for the Z80 processor. Additionally, utilities for manipulating object files created by the assembler are also included. The assembler syntax and related tool functions are based off of the toolchain found in Version 6 UNIX. By design, all parts of the toolchain are fairly lightweight. Certain features found in more modern toolchains are omitted. This makes it possible for the entire toolchain to be ported to run natively on the Z80 processor.

Tools include:

• as: Assembler, core of the TRASM toolchain. It is capable of assembling all documented and undocumented Z80 instructions. Unlike most Z80 assemblers, the TRASM assembler does not allow an origin to be defined, and all addresses should be assumed to be ambiguous. Object data is divided up into text, data, and bss segments. No macros are implemented, but custom types can be defined which act as primitive structs.
• ld: Link Editor, combines object files together. Text, data, and bss from all objects are relocated and spliced together. External symbols are resolved, and symbol tables are merged.
• reloc: Relocation Tool, moves object files around in memory. By default, all objects files have their origin set at 0x0000. This utility has the capacity to change that. Additionally, text/data or bss can be statically relocated to independent addresses. A final post-processing function exists which removes the header from the object file, creating a fully static binary.
• nm: Print name table, dumps all symbols in an object file. Symbols can be sorted in a number of different ways.
• size: Prints the size of the text, data, and bss segments.
• strip: Removes the symbol table, can also be done by ld or reloc.

All toolchain utilities generate or utilize object files in some way. TRASM object files are loosely based off of the original a.out format. A few changes have been made in respect to what goals this toolset aims to achieve. An object file is separated into 3 different segments:

• Binary Segment: Includes header and all the text/data.
• Relocation Segment: Includes segment and external relocation information.
• Symbol Table: Contains symbols records for global and external symbols.

All 16-bit values in the object file are little-endian unless specified otherwise.

This segment is where all actual instruction and data information resides. When assembling, bytes emitted are sorted into either the text or data segments. The exception to this is the header, which occupies the first 16 bytes of the text segment. Despite being automatically generated, it is treated as part of the text segment. This header contains information critical for manipulating and executing object files. Fields are as follows:

This segment contains relocation information for the binary segment. Addresses that are to be manipulated during linking and relocation are tracked in this segment. The first two bytes of this segment contain the number of relocation records. Directly after, that number of 3-byte relocation records are stored. Fields are as follows:

This segment exists directly after the relocation segment. Like the relocation segment, the first two bytes contain the number of symbols present in the table. Each symbol record occupies 11 bytes. External record types must match their type numbers in the relocation segment. Fields are as follows: