mem.c

//(c) uARM project    https://github.com/uARM-Palm/uARM    uARM@dmitry.gr

#include <string.h>
#include <stdlib.h>
#include "util.h"
#include "mem.h"


#define	NUM_MEM_REGIONS		128

struct ArmMemRegion {

	uint32_t pa;
	uint32_t sz;
	ArmMemAccessF aF;
	void* uD;
};

struct ArmMem {

	struct ArmMemRegion regions[NUM_MEM_REGIONS];
};


struct ArmMem *memInit(void)
{
	struct ArmMem *mem = (struct ArmMem*)malloc(sizeof(*mem));
	
	if (!mem)
		ERR("cannot alloc MEM");
	
	memset(mem, 0, sizeof (*mem));
	
	return mem;
}


void memDeinit(struct ArmMem *mem)
{
	(void)mem;
}

bool memRegionAdd(struct ArmMem *mem, uint32_t pa, uint32_t sz, ArmMemAccessF aF, void* uD)
{
	uint_fast8_t i;
	
	//check for intersection with another region
	
	for (i = 0; i < NUM_MEM_REGIONS; i++) {
		
		if (!mem->regions[i].sz)
			continue;
		if ((mem->regions[i].pa <= pa && mem->regions[i].pa + mem->regions[i].sz > pa) || (pa <= mem->regions[i].pa && pa + sz > mem->regions[i].pa))
			return false;		//intersection -> fail
	}
	
	
	//find a free region and put it there
	
	for (i = 0; i < NUM_MEM_REGIONS; i++) {
		if (mem->regions[i].sz == 0) {
		
			mem->regions[i].pa = pa;
			mem->regions[i].sz = sz;
			mem->regions[i].aF = aF;
			mem->regions[i].uD = uD;
		
			return true;
		}
	}
	
	//fail miserably
	
	return false;	
}

bool memAccess(struct ArmMem *mem, uint32_t addr, uint_fast8_t size, uint_fast8_t accessType, void* buf)
{
	bool ret = false, wantWrite = !!(accessType &~ MEM_ACCCESS_FLAG_NOERROR);
	uint_fast8_t i;
	
	for (i = 0; i < NUM_MEM_REGIONS; i++) {
		
		if (mem->regions[i].pa <= addr && mem->regions[i].pa + mem->regions[i].sz > addr) {
			
			ret = mem->regions[i].aF(mem->regions[i].uD, addr, size, wantWrite, buf);
			break;
		}
	}
	
	if (!ret && !(accessType & MEM_ACCCESS_FLAG_NOERROR)) {
		
		fprintf(stderr, "Memory %s of %u bytes to PA 0x%08lx fails\n", wantWrite ? "write" : "read", size, (unsigned long)addr);
		while(1);	//make debugging easier
	}
	
	return ret;
}