kvmmake() makes a complete kernel page table, matching Figure 3.3

1 files changed, 27 insertions, 15 deletions

diff --git a/kernel/vm.c b/kernel/vm.c
index bd53fd7..b47f111 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -15,33 +15,45 @@ extern char etext[];  // kernel.ld sets this to end of kernel code.
 
 extern char trampoline[]; // trampoline.S
 
-/*
- * create a direct-map page table for the kernel.
- */
-void
-kvminit()
+// Make a direct-map page table for the kernel.
+pagetable_t
+kvmmake(void)
 {
-  kernel_pagetable = (pagetable_t) kalloc();
-  memset(kernel_pagetable, 0, PGSIZE);
+  pagetable_t kpgtbl;
+
+  kpgtbl = (pagetable_t) kalloc();
+  memset(kpgtbl, 0, PGSIZE);
 
   // uart registers
-  kvmmap(UART0, UART0, PGSIZE, PTE_R | PTE_W);
+  kvmmap(kpgtbl, UART0, UART0, PGSIZE, PTE_R | PTE_W);
 
   // virtio mmio disk interface
-  kvmmap(VIRTIO0, VIRTIO0, PGSIZE, PTE_R | PTE_W);
+  kvmmap(kpgtbl, VIRTIO0, VIRTIO0, PGSIZE, PTE_R | PTE_W);
 
   // PLIC
-  kvmmap(PLIC, PLIC, 0x400000, PTE_R | PTE_W);
+  kvmmap(kpgtbl, PLIC, PLIC, 0x400000, PTE_R | PTE_W);
 
   // map kernel text executable and read-only.
-  kvmmap(KERNBASE, KERNBASE, (uint64)etext-KERNBASE, PTE_R | PTE_X);
+  kvmmap(kpgtbl, KERNBASE, KERNBASE, (uint64)etext-KERNBASE, PTE_R | PTE_X);
 
   // map kernel data and the physical RAM we'll make use of.
-  kvmmap((uint64)etext, (uint64)etext, PHYSTOP-(uint64)etext, PTE_R | PTE_W);
+  kvmmap(kpgtbl, (uint64)etext, (uint64)etext, PHYSTOP-(uint64)etext, PTE_R | PTE_W);
 
   // map the trampoline for trap entry/exit to
   // the highest virtual address in the kernel.
-  kvmmap(TRAMPOLINE, (uint64)trampoline, PGSIZE, PTE_R | PTE_X);
+  kvmmap(kpgtbl, TRAMPOLINE, (uint64)trampoline, PGSIZE, PTE_R | PTE_X);
+
+  // map kernel stacks
+  proc_mapstacks(kpgtbl);
+  
+  return kpgtbl;
+}
+
+// Initialize the one kernel_pagetable
+void
+kvminit(void)
+{
+  kernel_pagetable = kvmmake();
 }
 
 // Switch h/w page table register to the kernel's page table,
@@ -112,9 +124,9 @@ walkaddr(pagetable_t pagetable, uint64 va)
 // only used when booting.
 // does not flush TLB or enable paging.
 void
-kvmmap(uint64 va, uint64 pa, uint64 sz, int perm)
+kvmmap(pagetable_t kpgtbl, uint64 va, uint64 pa, uint64 sz, int perm)
 {
-  if(mappages(kernel_pagetable, va, sz, pa, perm) != 0)
+  if(mappages(kpgtbl, va, sz, pa, perm) != 0)
     panic("kvmmap");
 }