tool-z80asm

Query the CPU capability fixtures under src/z80asm/dev/cpu using rg against the cpu_test_<cpu>_ok.asm and cpu_test_<cpu>_err.asm files. The ok files show accepted forms with their emitted encodings, while err files list forms the assembler must reject for that -m target.

Use the -x flag followed by the library name and an @list of object files, for example z88dk-z80asm -xlibname.lib file1.o file2.o. The -d flag enables date-based incremental rebuilds during library builds.

Strict mode forbids synthetic opcodes, which are assembler sugar expanded into multiple real instructions in normal mode. Forms like ld de,hl assemble in normal mode but fail in strict mode, while real extended ops like sub hl,bc remain legal in both.

PHASE stores bytes at the current section PC while resolving labels and $ to a run address as if ORG were set. The linker has no knowledge of PHASE, so runtime code must copy the phased bytes to the run address with ldir before calling those labels.

z88dk requires Zilog mnemonics for all tree code, including library, CRT, and examples. The assembler accepts Intel mnemonics on 8080/8085 only for compatibility with external sources, so translate Intel syntax to Zilog when importing foreign code.

Labels inside PHASE resolve to the run address, not the storage address where the bytes actually sit. You must copy the phased block to its run address (typically with ldir) before any call or jp to those labels, or the CPU jumps to unpopulated memory.