/*
 * Milkymist SoC (Software)
 * Copyright (C) 2012 Yann Sionneau <yann.sionneau@gmail.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <hal/mmu.h>
#include <base/mmu.h>
#include <base/stdio.h>

#ifdef __ASSEMBLER__
#define MMPTR(x) x
#else
#define MMPTR(x) (*((volatile unsigned int *)(x)))
#endif
#define CSR_UART_RXTX 		MMPTR(0xe0000000)

void f(void) {
	char c = '@';
	CSR_UART_RXTX = c;
//	asm volatile("bi f" ::: ); // We intinitely loop to f()
	asm volatile("xor r0, r0, r0\n\t"
		     "xor r0, r0, r0" ::: );
}

void itlbtest(void) {
	register unsigned int stack, f_addr;
	unsigned int *p;
	unsigned int *pdest;
	unsigned int addr;

	asm volatile("mv %0, sp" : "=r"(stack) :: );
	printf("stack == 0x%08X\n", stack);

	printf("f() is located at 0x%p\n", f);

	f_addr = 0x44004000;
	printf("Mapping f() into virtual memory at 0x%08X [physical == 0x%08X]\n", f_addr, f_addr+0x1000);

//	for (addr = 0x00860000 ; addr <= 0x00874000 ; addr += 0x1000)
//		mmu_map(addr, addr, DTLB_MAPPING | MAPPING_CAN_READ);

	mmu_map(stack, stack, DTLB_MAPPING | MAPPING_CAN_READ | MAPPING_CAN_WRITE);
	mmu_map(f_addr, f_addr + 0x1000, ITLB_MAPPING | MAPPING_CAN_READ);
	mmu_map(itlbtest, itlbtest, ITLB_MAPPING | MAPPING_CAN_READ);
	mmu_map(call_function_with_itlb_enabled, call_function_with_itlb_enabled, ITLB_MAPPING | MAPPING_CAN_READ);
	puts("Mapping DONE");

//	mmu_itlb_invalidate_line(f_addr);

	// We copy f's code to 0x44005000
	for (p = f, pdest = 0x44005000 ; p < f + 0x1000 ; p++, pdest++)
		*pdest = *p;
	puts("Copy DONE");

	asm volatile("wcsr DCC, r0\n\t"
		     "xor r0, r0, r0\n\t"
		     "xor r0, r0, r0\n\t"
		     "xor r0, r0, r0\n\t"
		     "xor r0, r0, r0");
	asm volatile("wcsr ICC, r0\n\t"
		     "xor r0, r0, r0");
	puts("Instruction and Data caches have been invalidated");

	call_function_with_itlb_enabled(f_addr);
	disable_dtlb();
	disable_itlb();
	puts("Call DONE");
}