AJVM is an assembler for the amic-0 assembly language.

• Build
• Usage
• Syntax and semantics
• References

The project is built with Gradle. The required version is automatically downloaded by the wrapper, so simply clone the repository and run the build task:

$ git clone https://github.com/albmoriconi/ajvm.git
$ cd ajvm
$ ./gradlew build

The built program archives with executables and library dependencies can be found in the build/distributions directory.

To build the Javadoc for the project, run the javadoc Gradle task. The produced documentation can be found in the build/docs/javadoc directory.

usage: ajvm [options] <input>
Assembler for AJVM assembly language

options:
 -f <format>   output format: binary (default) | text
 -h,--help     display this help and exit
 -o <file>     write output to <file>

The language is based on the IJVM ISA described in Tanenbaum (2013). This section describes the changes made to its syntax and semantics.

An AJVM assembly program is composed of two parts: a constant area and a method area, in this order.

The constant area is comprised between the .constant and .endconstant keywords and contains constant declarations in the form name value, where value can be a decimal or hexadecimal (with the 0x prefix) integer literal:

.constant
c1 0x8
c2 25
.endconstant

The method area is composed of the .main method definition, that has to be defined first and without parameters, and, optionally, any number of additional methods.

Each method definition is comprised between .name (a method name always begins with the . character), optionaly followed by the method parameter names between parentheses, and .endmethod, and contains an optional variable block, where the names of local variables are declared, and an instruction block:

.main
.var
a
.endvar
LDC_W c1
LDC_W c2
INVOKEVIRTUAL .sum
ISTORE a
HALT
.endmethod

.sum(v1, v2)
ILOAD v1
ILOAD v2
IADD
IRETURN
.endmethod

Each instruction can be labeled with the label: <instruction> syntax; labels are local to methods.

An HALT instruction has been added to the language; it causes the processor execution to halt.

The language is case sensitive. Instructions are upper case, other keywords are lower case.

Comments go from a # character to the end of line.

• Tanenbaum, A.S, and Austin, T. (2013). Structured Computer Organization (6th ed.). Pearson.