diff options
Diffstat (limited to 'sys/arch/amd64/cpu')
| -rw-r--r-- | sys/arch/amd64/cpu/mmu.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/sys/arch/amd64/cpu/mmu.c b/sys/arch/amd64/cpu/mmu.c index 65c4e46..15ba19a 100644 --- a/sys/arch/amd64/cpu/mmu.c +++ b/sys/arch/amd64/cpu/mmu.c @@ -28,10 +28,12 @@ */ #include <sys/types.h> +#include <sys/errno.h> #include <sys/cdefs.h> #include <kern/panic.h> #include <mu/mmu.h> #include <vm/vm.h> +#include <vm/phys.h> #include <md/vas.h> /* @@ -76,6 +78,32 @@ mu_pmap_writevas(struct mmu_vas *vas) return 0; } +int +mu_pmap_forkvas(struct mmu_vas *result) +{ + struct mmu_vas vas; + uintptr_t paddr, *pml4_dest; + uintptr_t *pml4_src; + + mu_pmap_readvas(&vas); + paddr = vm_phys_alloc(1); + if (paddr == 0) { + return -ENOMEM; + } + + pml4_dest = PHYS_TO_VIRT(paddr); + pml4_src = PHYS_TO_VIRT(vas.cr3); + for (uint16_t i = 0; i < 512; ++i) { + if (i < 256) { + pml4_dest[i] = 0; + } else { + pml4_dest[i] = pml4_src[i]; + } + } + + return 0; +} + void mu_pmap_init(void) { |