/* *********************************************************************** *
 * Example that shows how to use the APU just for user access
 *
 * Description
 * This example shows how to implement an APU library that implements accesses
 * to the USR: access class.
 *
 * This simple example just mirrors the memory of the real core, but inverts
 * all bits.
 *
 * (c) Lauterbach GmbH
 * http://www.lauterbach.com/
 *
 * $Id$
 *
 * *********************************************************************** */

#include "t32apu.h"
#include <string.h>
#include <stdlib.h>

enum {
	MEMORY_ACCESS_USER = 0
};

static int APUAPI CallbackMemoryRead(apuContext context, apuCallbackStruct *cbs, apuPtr proprietary) {
	apuWord i;
	int error;

	switch (cbs->x.memory.flags) {
	case MEMORY_ACCESS_USER:
		error = APU_ReadMemory(context, cbs->x.memory.address, T32_MEMORY_ACCESS_DATA, cbs->x.memory.data, cbs->x.memory.length, cbs->x.memory.width);

		if (error == APU_OK) {
			for (i = 0; i < cbs->x.memory.length; ++i) {
				cbs->x.memory.data[i] = ~cbs->x.memory.data[i];
			}
		}

		return error;
	default:
		/* this should never happen */
		APU_Printf(context, "access to unknown access class %d", cbs->x.memory.flags);
		return APU_FAIL;
	}
}

static int APUAPI CallbackMemoryWrite(apuContext context, apuCallbackStruct *cbs, apuPtr proprietary) {
	apuWord i;
	int error;
	uint8_t *data;

	switch (cbs->x.memory.flags) {
	case MEMORY_ACCESS_USER:
		data = (uint8_t *)malloc(cbs->x.memory.length);

		if (data == NULL) {
			return APU_FAIL;
		}

		for (i = 0; i < cbs->x.memory.length; ++i) {
			data[i] = ~cbs->x.memory.data[i];
		}

		error = APU_WriteMemory(context, cbs->x.memory.address, T32_MEMORY_ACCESS_DATA, data, cbs->x.memory.length, cbs->x.memory.width);
		free(data);
		return error;
	default:
		/* this should never happen */
		APU_Printf(context, "access to unknown access class %d", cbs->x.memory.flags);
		return APU_FAIL;
	}
}

int APUAPI APU_Init(apuContext context, apuCallbackStruct * cbs)
{
	strcpy(cbs->x.init.modelname, __DATE__ " USRACCESS demo");

	if (cbs->x.init.argc != 1) {
		APU_Warning(context, "parameters: none");
		return APU_FAIL;
	}

	/* Define memory region for USRACCES. Doing this notifies TRACE32 that this
	 * APU should intercept accesses to USR: addresses. */
	APU_DefineMemory(context, MEMORY_ACCESS_USER, "USR", 1, 4);

	APU_RegisterMemoryReadCallback(context, CallbackMemoryRead, NULL);
	APU_RegisterMemoryWriteCallback(context, CallbackMemoryWrite, NULL);

	return APU_OK;
}