Add readme

LICENSE

@@ -21,4 +21,4 @@ DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Makefile

@@ -4,7 +4,7 @@ CFLAGS := -Wall -Wextra -Werror -O2 -ansi -std=gnu99
 DEBUG := -DNDEBUG
 INSTALL_PATH := /usr/local
 
-LIB = simak65.a
+LIB = libsimak65.a
 HEADER = simak65.h
 OBJ = addrmode.o alu.o bus.o decoder.o exec.o simak65.o
 

README.md

@@ -0,0 +1,61 @@
+# simak65 - 6502 CPU simulator library
+
+This simulator is based on the simualator of [AK6502 CPU](https://github.com/agkaminski/AK6502).
+NMOS version of the CPU is simulated, cycle accurate. There's no undocumented intructions support,
+invalid opcodes are decoded as `nop`.
+
+## Build
+
+There're no dependencies, only `make` and `gcc` are needed. Simply type `make` to build the library.
+It can be installed to `/usr/local/lib` via `sudo make install`, along with the api header (to `/usr/local/include`).
+
+## API
+
+Library interface is available in `simak65.h` header.
+
+### struct simak65_bus
+
+This structure holds CPU bus read/write callback, that are need to provided by the library user.
+
+### struct simak65_cpustate
+
+This structure holds internal CPU state. It is stored by the library user and needs to be passed
+to the library functions.
+
+### void simak65_step(struct simak65_cpustate *cpu, unsigned int *cycles)
+
+Execute the next instruction.
+- cpu - cpu state,
+- cycles - optional (can be NULL), number of cycles passed for the execution of the instruction
+is added to this variable.
+
+### void simak65_rst(struct simak65_cpustate *cpu, unsigned int *cycles)
+
+Perform the CPU reset. This operation must be performed pefored before executing first instruction.
+- cpu - cpu state,
+- cycles - optional (can be NULL), number of cycles passed for the execution of the instruction
+is added to this variable.
+
+### void simak65_nmi(struct simak65_cpustate *cpu, unsigned int *cycles)
+
+Execute the non-maskable interrupt.
+- cpu - cpu state,
+- cycles - optional (can be NULL), number of cycles passed for the execution of the instruction
+is added to this variable.
+
+### void simak65_irq(struct simak65_cpustate *cpu, unsigned int *cycles)
+
+Execute the interrupt.
+- cpu - cpu state,
+- cycles - optional (can be NULL), number of cycles passed for the execution of the instruction
+is added to this variable.
+
+### void simak65_init(struct simak65_cpustate *cpu, const struct simak65_bus *ops)
+
+Initialize the library and the cpu state.
+- cpu - cpu state,
+- ops - CPU memory bus callbacks.
+
+## License
+
+See LICENSE for details.

addrmode.c

@@ -282,13 +282,3 @@ enum argtype addrmode_getArgs(struct simak65_cpustate *cpu, u8 *args, enum addrm
 	return arg_type;
 }
 
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addrmode.h

@@ -16,3 +16,4 @@ u8 addrmode_nextpc(struct simak65_cpustate *cpu);
 enum argtype addrmode_getArgs(struct simak65_cpustate *cpu, u8 *args, enum addrmode mode, unsigned int *cycles);
 
 #endif /* SIMAK65_ADDRMODE_H_ */
+