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OS_Project/Part3/09_memory/libc/mem.c

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2023-10-18 18:04:33 +00:00
#include "mem.h"
void memory_copy(u8 *source, u8 *dest, int nbytes) {
int i;
for (i = 0; i < nbytes; i++) {
*(dest + i) = *(source + i);
}
}
void memory_set(u8 *dest, u8 val, u32 len) {
u8 *temp = (u8 *)dest;
for ( ; len != 0; len--) *temp++ = val;
}
// See globals.h for kmem_addr global declaration
// kmem_addr is reserved block of memory for kernel to store linked list nodes
/* Implementation is just a pointer to some free memory which
* keeps growing */
u32 kmalloc(u32 size, int align, u32 *phys_addr) {
/* Pages are aligned to 4K, or 0x1000 */
if (align == 1 && (kmem_addr & 0xFFFFF000)) {
kmem_addr &= 0xFFFFF000;
kmem_addr += 0x1000;
}
char c[16];
hex_to_ascii( *phys_addr, c, 16);
kprint("Inside kmalloc phys_addr (before) = ");
kprint(c);
kprint(" --- ");
/* Save the physical address */
*phys_addr = kmem_addr;
hex_to_ascii( *phys_addr, c, 16);
kprint("(after) phys_addr = ");
kprint(c);
kprint("\n");
u32 ret = kmem_addr;
kmem_addr += size; /* Remember to increment the pointer */
return ret;
}
// See globals.h for user_start global declaration
// umem_addr is reserved block of memory for kernel to store linked list nodes
/* Implementation is just a pointer to some free memory which
* keeps growing */
u32 umalloc(u32 size, int align, u32 *phys_addr) {
/* Pages are aligned to 4K, or 0x1000 */
if (align == 1 && (umem_addr & 0xFFFFF000)) {
umem_addr &= 0xFFFFF000;
umem_addr += 0x1000;
}
char c[16];
hex_to_ascii( *phys_addr, c, 16);
kprint("Inside umalloc phys_addr (before) = ");
kprint(c);
kprint(" --- ");
/* Save the physical address */
*phys_addr = umem_addr;
hex_to_ascii( *phys_addr, c, 16);
kprint("(after) phys_addr = ");
kprint(c);
kprint("\n");
u32 ret = umem_addr;
umem_addr += size; /* Remember to increment the pointer */
return ret;
}