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#include <apos/types.h>
#include <apos/attrs.h>
#include <apos/utils.h>
#include <apos/vmem.h>
#include <vmem.h>
#include <csr.h>
/* assume 64 bit for now */
struct __packed init_vmem {
int *leaf[512];
};
struct init_vmem *root_branch;
#define to_pte(a, f) (((a) >> 12) << 10 | (f))
/* assume Sv39 for now */
void init_bootmem()
{
size_t flags = VM_V | VM_X | VM_R | VM_W;
extern char *__init_start;
root_branch = (struct init_vmem *)align_down((size_t)&__init_start - SZ_4K, SZ_4K);
/* direct mapping (temp) */
for(size_t i = 0; i < CSTACK_PAGE; ++i)
root_branch->leaf[i] = (int*)to_pte(SZ_1G * i, flags);
/* kernel (also sort of direct mapping) */
flags |= VM_G;
for(size_t i = KSTART_PAGE; i < IO_PAGE; ++i)
root_branch->leaf[i] = (int *)to_pte(RAM_BASE + SZ_1G * (i - 256), flags);
/* kernel IO, map to 0 for now, will be updated in the future */
root_branch->leaf[IO_PAGE] = (int *)to_pte(0, flags);
csr_write(CSR_SATP, SATP_MODE_Sv39 | ((size_t)root_branch >> 12));
}
void move_kernel()
{
extern char *__init_end;
extern char *__kernel_size;
size_t sz = (size_t)&__kernel_size;
char *src = (char *)&__init_end;
char *dst = (char *)VM_KERN;
for(size_t i = 0; i < sz; ++i)
dst[i] = src[i];
}
#define __va_reg(reg)\
{\
vm_t reg = 0;\
__asm__("mv %0, " QUOTE(reg) : "=r" (reg) :: );\
reg = (vm_t)__va(reg);\
__asm__("mv " QUOTE(reg) ", %0" :: "rK" (reg) : );\
}
void init(void *fdt)
{
extern char *__init_end;
extern void jump_to_kernel(void *k, void *fdt);
init_bootmem();
move_kernel();
__va_reg(sp);
__va_reg(fp);
__va_reg(gp);
jump_to_kernel((void *)VM_KERN, __va(fdt));
}
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