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memory.c
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memory.c
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#include "kernel.h"
void memman_init(struct MEMMAN *man)
{
man->frees = 0; // total info
man->maxfrees = 0; // free maxfrees
man->lostsize = 0; // failure size
man->losts = 0; // release failures
return;
}
unsigned int memman_total(struct MEMMAN *man)
{
// total free size
unsigned int i, t = 0;
for (i = 0; i < man->frees; i++) {
t += man->free[i].size;
}
return t;
}
unsigned int memman_alloc(struct MEMMAN *man, unsigned int size)
{
// allocation
unsigned int i, a;
for (i = 0; i < man->frees; i++) {
if (man->free[i].size >= size) { // big enough
a = man->free[i].addr;
man->free[i].addr += size; // update
man->free[i].size -= size;
if (man->free[i].size == 0) {
man->frees--; // delete block
for (; i < man->frees; i++) { // next
man->free[i] = man->free[i + 1];
}
}
return a;
}
}
return 0;
}
int memman_free(struct MEMMAN *man, unsigned int addr, unsigned int size)
{
int i, j;
// find addr
for (i = 0; i < man->frees; i++) {
if (man->free[i].addr > addr) {
break;
}
}
/* free[i - 1].addr < addr < free[i].addr */
if (i > 0) {
if (man->free[i - 1].addr + man->free[i - 1].size == addr) {
man->free[i - 1].size += size;
if (i < man->frees) {
if (addr + size == man->free[i].addr) {
man->free[i - 1].size += man->free[i].size;
man->frees--;
for (; i < man->frees; i++) {
man->free[i] = man->free[i + 1];
}
}
}
return 0;
}
}
if (i < man->frees) {
if (addr + size == man->free[i].addr) {
man->free[i].addr = addr;
man->free[i].size += size;
return 0;
}
}
if (man->frees < MEMMAN_FREES) {
for (j = man->frees; j > i; j--) {
man->free[j] = man->free[j - 1];
}
man->frees++;
if (man->maxfrees < man->frees) {
man->maxfrees = man->frees;
}
man->free[i].addr = addr;
man->free[i].size = size;
return 0;
}
man->losts++;
man->lostsize += size;
return -1;
}
unsigned int memtest(unsigned int start, unsigned int end){
char flg486 = 0;
unsigned int eflg, cr0, i;
/* detect 486 */
eflg = _io_load_eflags();
eflg |= EFLAGS_AC_BIT;
_io_store_eflags(eflg);
eflg = _io_load_eflags();
if ((eflg & EFLAGS_AC_BIT) != 0){
flg486 = 1;
}
eflg &= ~EFLAGS_AC_BIT; // AC-bit = 0
_io_store_eflags(eflg);
if (flg486 != 0){
cr0 = _load_cr0();
cr0 |= CR0_CACHE_DISABLE; // disable cache
_store_cr0(cr0);
}
i = _memtest_sub(start,end);
if(flg486 != 0){
cr0 = _load_cr0();
cr0 &= ~ CR0_CACHE_DISABLE; // enable cache
_store_cr0(cr0);
}
return i;
}
unsigned int memtest_sub(unsigned int start, unsigned int end){
unsigned int i, *p, old, pat0 = 0xaa55aa55, pat1 = 0x55aa55aa;
for(i = start;i<=end;i+= 0x1000){
p = (unsigned int *) (i + 0xffc); // test last 4 bytes
old = *p;
*p = pat0;
*p ^= 0xffffffff;
if( *p != pat1 ){
not_memory:
*p = old;
break;
}
*p ^= 0xffffffff;
if (*p != pat0){
goto not_memory;
}
*p = old;
}
return i;
}
unsigned int memman_alloc_4k(struct MEMMAN *man, unsigned int size){
unsigned int a;
size = (size + 0xfff) & 0xfffff000; // round up to 4k
a = memman_alloc(man, size);
return a;
}
int memman_free_4k(struct MEMMAN *man, unsigned int addr, unsigned int size){
int i;
size = (size + 0xfff) & 0xfffff000;
i = memman_free(man, addr, size);
return i;
}