/* rom.cpp - emulate a ROM in QBUS/UNIBUS IO page

 Copyright (c) 2020, Joerg Hoppe, j_hoppe@t-online.de, www.retrocmp.com

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 7-feb-2020   JH      begin

 A ROM is implemented by DDR memory, which is accessed by PRU
 if pru_iopage_registers_t.register_handles[addr] == 0xff

 State:
 Code in a ROM can be loaded from a disk file (MACRO11 listing),
 a map with code labels is managed.
 A loaded ROM can be relocated (neeed for M9312 boot ROMS, which are all 173000)
 A loaded ROM can be installed to QBUS/UNIBUS (by setting PRU maps)
 */

#include "logger.hpp"
#include "qunibusadapter.hpp"
#include "ddrmem.h"
#include "rom.hpp"

// fill from file
// uses global memory buffer "membuffer"

// size if ROM in 16bit words
rom_c::rom_c(std::string _name, unsigned _wordcount, uint32_t _baseaddress) 
{
	log_label = "ROM";

	name = _name;
	wordcount = _wordcount;
	baseaddress = _baseaddress;
	cells.reserve(_wordcount);
}

// fill ROM with pattern
void rom_c::fill(uint16_t value) 
{
	for (unsigned i = 0; i < wordcount; i++)
		cells[i] = value;
	codelabels.clear() ; // no code in ROM now
}

bool rom_c::load_macro11_listing(const char *fname) 
{
	bool load_ok;
	uint32_t lastaddr;

	fill(0xffff); // "empty" pattern

	membuffer->init();
	load_ok = membuffer->load_macro11_listing(fname, &codelabels);
	if (load_ok) {
		// move data to intern array. 
		// fill undefined data with 0xff.
		// error, if file defines more data then base_addr+size
		membuffer->get_addr_range(&baseaddress, &lastaddr);
		unsigned loaded_words = (lastaddr - baseaddress) / 2 + 1;

		if (loaded_words > wordcount) {
			ERROR("Data overflow: file \"%s\" contains %u words, ROM size is %u.", fname,
					loaded_words, wordcount);
			load_ok = false;
		}
	}

	if (load_ok) {
		// copy loaded words into ROM cells[]
		for (unsigned i = 0; i < wordcount; i++) {
			uint32_t addr = baseaddress + 2 * i;
			if (membuffer->is_valid(addr))
				cells[i] = membuffer->get_word(addr);
		}
	}

	return load_ok;
}

void rom_c::dump(FILE *f) 
{
	unsigned addr;
	fprintf(f, "Data of ROM \"%s\", baseaddress=%s, wordcount=%u:\n", name.c_str(),
			qunibus->addr2text(baseaddress), wordcount);
	for (addr = baseaddress; addr < baseaddress + 2 * wordcount; addr += 2)
		fprintf(f, "%06o %06o\n", addr, get_data(addr));
	codelabels.print(stderr);
}

// get a cell, or exception
uint16_t rom_c::get_data(uint32_t addr) 
{
	if (addr < baseaddress || (addr >= baseaddress + 2 * wordcount)) {
		ERROR("get_data(): illegal address %s", qunibus->addr2text(addr));
		return 0;
	}
	return cells[(addr - baseaddress) / 2];
}

// set a cell
void rom_c::set_data(uint32_t addr, uint16_t value) 
{
	if (addr < baseaddress || (addr >= baseaddress + 2 * wordcount)) {
		ERROR("set_data(): illegal address %s", qunibus->addr2text(addr));
		return;
	}
	cells[(addr - baseaddress) / 2] = value;
}

// move base address, correct code label map
// must not be installed on QBUS/UNIBUS !
void rom_c::relocate(uint32_t new_base_addr) 
{
	if (new_base_addr + 2 * wordcount > qunibus->addr_space_byte_count) {
		ERROR("Relocation to %s would exceed addressrange at %06o", qunibus->addr2text(new_base_addr), qunibus->addr_space_byte_count);
		return;
	}
	int delta = new_base_addr - baseaddress;
	baseaddress = new_base_addr;

	codelabels.relocate(delta);
}

// implemement on QBUS/UNIBUS
void rom_c::install(void) 
{
	// check whether all cells are in IOpage

	// register onto QBUS/UNIBUS IOpage
	// if a IOpage address is already marked as "device register"
	// that address is silently NOT defined to be a ROM
	// so ROM ranges may be superseded with registers 
	// (M9312, 773024/26)
	for (unsigned i = 0; i < wordcount; i++) {
		uint32_t addr = baseaddress + 2 * i;
		// set value of ROM cell in background DDR RAM
		if (!ddrmem->iopage_deposit(addr, cells[i]))
			FATAL("setting IOpage background DDR RAM failed");
		// set QBUS/UNIBUS address as "ROM", to access DDR mem cell
		if (!qunibusadapter->register_rom(addr))
			break; // error
	}
}

// remove from QBUS/UNIBUS
void rom_c::uninstall(void) 
{
	for (unsigned i = 0; i < wordcount; i++) {
		uint32_t addr = baseaddress + 2 * i;
		qunibusadapter->unregister_rom(addr);
	}
}