view x86_backend.c @ 478:2e4a4188cfb0

Fix DMA fill so that it does not cause observable changes to the FIFO. Get DMA copy mostly correct from an observable ffect perspective. DMA copy probably does not reflect internal implementation still given that evidence seems to suggest no FIFO usage at all.
author Mike Pavone <pavone@retrodev.com>
date Tue, 17 Sep 2013 00:11:45 -0700
parents 140af5509ce7
children
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/*
 Copyright 2013 Michael Pavone
 This file is part of BlastEm. 
 BlastEm is free software distributed under the terms of the GNU General Public License version 3 or greater. See COPYING for full license text.
*/
#include "x86_backend.h"
#include <stdlib.h>

deferred_addr * defer_address(deferred_addr * old_head, uint32_t address, uint8_t *dest)
{
	deferred_addr * new_head = malloc(sizeof(deferred_addr));
	new_head->next = old_head;
	new_head->address = address & 0xFFFFFF;
	new_head->dest = dest;
	return new_head;
}

void remove_deferred_until(deferred_addr **head_ptr, deferred_addr * remove_to)
{
	for(deferred_addr *cur = *head_ptr; cur && cur != remove_to; cur = *head_ptr)
	{
		*head_ptr = cur->next;
		free(cur);
	}
}

void process_deferred(deferred_addr ** head_ptr, void * context, native_addr_func get_native)
{
	deferred_addr * cur = *head_ptr;
	deferred_addr **last_next = head_ptr;
	while(cur)
	{
		uint8_t * native = get_native(context, cur->address);//get_native_address(opts->native_code_map, cur->address);
		if (native) {
			int32_t disp = native - (cur->dest + 4);
			uint8_t * out = cur->dest;
			*(out++) = disp;
			disp >>= 8;
			*(out++) = disp;
			disp >>= 8;
			*(out++) = disp;
			disp >>= 8;
			*out = disp;
			*last_next = cur->next;
			free(cur);
			cur = *last_next;
		} else {
			last_next = &(cur->next);
			cur = cur->next;
		}
	}
}