# Assembler
### CLI application written in C

The assembler converts the written assembly into a memory image for the EIPA processor. This memory image then contains the instructions in as machiene code which is readable by the EIPA processor

It is basically made up of 4 building blocks:
### 1. lexer
The lexer takes the file with the written assembly and converts it into the individual components (tokens). It also takes into account if, for example, there are multiple spaces between the parts of the instruction, so that the other parts of the assembler do not have to worry about that. It converts e.g. the line
`INP 31 ; A comment`
into the parts `|INP|, |31|, |end of instruction|`.

### 2. error analyzer
The error analyzer takes the tokens from the lexer, and checks e.g. if the address of an instruction is too large, if an instruction that needs an address has one, if there are any typos, etc. If it finds an error, it aborts the program.

### 3. target code generator
The target code generator converts the tokens from the lexer, after checking them for errors, into machine code readable by the EIPA processor.

### 4. image saver
The image saver stores the generated machine code in an EIPA memory image, which can then be loaded into memory by the processor and executed.


The design of the expected assembly code is described in ``design.txt``.

## Building
### Dependencies
You need to have
1. a compiler
2. make

installed on your system. While clang is being used by default, you can also use another compiler (e.g. gcc) by running `export CC=yourcompiler` or by changing 'clang' at the top of `Makefile` and `dependency_setup.sh` (where the variable CC is defined) to your preferred compiler.

To install the simple_hashtable library required for the Assembler, you can run the `dependency_setup.sh` file, or manually compile the library and place it in `lib/shash.o`.

Finally, run make to get build the Assembler to `build/eipaasm`