RDRAMA

The RealDRAM assembler.

Introduction

RDRAMA is an assembler for the RealDRAM architecture, written in lex, yacc and C++.

Running sudo make install will install four programs into /bin:

rdrama-preprocessor: parses and executes all preprocessor directives, and also removes comments.
rdrama-resolver: creates a symbol table for all the declarations, such as start: and br start.
rdrama-assembler: creates the final binary.
rdrama: a script to run all the programs in order, this is what you should use.

My idea was to make this as similar as possible to NASM, which is an assembler I'm quite used to.

In this file, an address can be specified in decimal (br 0) or hex (br 0xFE).

Mnemonic	First argument	Second argument	Third argument	Equivalent opcode	Description
`br`	addr			`00000000`	Conditional branch, jumps if the flag is up.
`ibr`	indirect addr			`01000000`	Indirect conditional branch.
`nand`, `nandd`	addr			`11100000`	NAND-BYTE-ITSELF-DIRECT
`nandi`	indirect addr			`11100011`	NAND-BYTE-ITSELF-INDIRECT
`nand`, `nanddd`	addr (orig)	addr (dest)		`11000000`	NAND-BYTE-OTHER-DIRECT-DIRECT
`nandi`	indirect addr (orig)	indirect addr (dest)		`11000011`	NAND-BYTE-OTHER-INDIRECT-INDIRECT
`nandid`	indirect addr (orig)	addr (dest)		`11000010`	NAND-BYTE-OTHER-INDIRECT-DIRECT
`nanddi`	addr (orig)	indirect addr (dest)		`11000001`	NAND-BYTE-OTHER-DIRECT-INDIRECT
`bnand`, `bnandd`	0 <= bit <= 7	addr		`101xxx00`	NAND-BIT-ITSELF-DIRECT
`bnandi`	bit	indirect addr		`101xxx11`	NAND-BIT-ITSELF-INDIRECT
`bnand`, `bnanddd`	bit	addr (orig)	addr (dest)	`100xxx00`	NAND-BIT-OTHER-DIRECT
`bnandi`	bit	indirect addr (orig)	indirect addr (dest)	`100xxx11`	NAND-BIT-OTHER-INDIRECT
`bnandid`	bit	indirect addr (orig)	addr (dest)	`100xxx10`	NAND-BIT-OTHER-INDIRECT-DIRECT
`bnanddi`	bit	addr (orig)	indirect addr (dest)	`100xxx01`	NAND-BIT-OTHER-DIRECT-INDIRECT

A declaration is a tag linked to an address which can be used in any instruction as if it was a regular address.

br next
thing: nand 0xFFFD
next: nand thing

A declaration behaves like an address, and addresses can be added. For instance, string_addr+1 will work.

RDRAMA supports literal insertion. That is, raw bytes. There are two pseudoinstructions for this: rawd (raw data, bytes) and rawa (raw address).

ibr jump
jump: rawa 0xFFFF

Comments are done with a semicolon, like in NASM.

bnand 0, 0xFFFD ; Read a character.