/* mark the physical pages backing a range of virtual as in use.
* allocate the physical pages and throw them away */
static void mark_pages_in_use(vaddr_t va, size_t len)
{
LTRACEF("va 0x%lx, len 0x%zx\n", va, len);
struct list_node list;
list_initialize(&list);
/* make sure we are inclusive of all of the pages in the address range */
len = PAGE_ALIGN(len + (va & (PAGE_SIZE - 1)));
va = ROUNDDOWN(va, PAGE_SIZE);
LTRACEF("aligned va 0x%lx, len 0x%zx\n", va, len);
for (size_t offset = 0; offset < len; offset += PAGE_SIZE) {
uint flags;
paddr_t pa;
status_t err = arch_mmu_query(va + offset, &pa, &flags);
if (err >= 0) {
//LTRACEF("va 0x%x, pa 0x%x, flags 0x%x, err %d\n", va + offset, pa, flags, err);
/* alloate the range, throw the results away */
pmm_alloc_range(pa, 1, &list);
} else {
panic("Could not find pa for va 0x%lx\n", va);
}
}
}
void platform_early_init(void)
{
/* initialize the interrupt controller */
arm_gic_init();
arm_generic_timer_init(ARM_GENERIC_TIMER_PHYSICAL_INT, 0);
uart_init_early();
/* look for a flattened device tree just before the kernel */
const void *fdt = (void *)KERNEL_BASE;
int err = fdt_check_header(fdt);
if (err >= 0) {
/* walk the nodes, looking for 'memory' */
int depth = 0;
int offset = 0;
for (;;) {
offset = fdt_next_node(fdt, offset, &depth);
if (offset < 0)
break;
/* get the name */
const char *name = fdt_get_name(fdt, offset, NULL);
if (!name)
continue;
/* look for the 'memory' property */
if (strcmp(name, "memory") == 0) {
int lenp;
const void *prop_ptr = fdt_getprop(fdt, offset, "reg", &lenp);
if (prop_ptr && lenp == 0x10) {
/* we're looking at a memory descriptor */
//uint64_t base = fdt64_to_cpu(*(uint64_t *)prop_ptr);
uint64_t len = fdt64_to_cpu(*((const uint64_t *)prop_ptr + 1));
/* trim size on certain platforms */
#if ARCH_ARM
if (len > 1024*1024*1024U) {
len = 1024*1024*1024; /* only use the first 1GB on ARM32 */
printf("trimming memory to 1GB\n");
}
#endif
/* set the size in the pmm arena */
arena.size = len;
}
}
}
}
/* add the main memory arena */
pmm_add_arena(&arena);
/* reserve the first 64k of ram, which should be holding the fdt */
struct list_node list = LIST_INITIAL_VALUE(list);
pmm_alloc_range(MEMBASE, 0x10000 / PAGE_SIZE, &list);
}
