Check multiboot2 header length, and if needed map the next page as well

1 files changed, 7 insertions, 0 deletions

diff --git a/src/vmm.cc b/src/vmm.cc
index 3c90c48..abce5b8 100644
--- a/src/vmm.cc
+++ b/src/vmm.cc
@@ -78,6 +78,13 @@ Result<uint32_t, vmm::Error> vmm::map(uint32_t addr, const vmm::address dest) {
     return Result<uint32_t, vmm::Error>{vmm::AddressAlreadyMapped};
 }
 
+void vmm::unmap(const address d) {
+  if (directory[d.table_idx] == 0) return;
+  page_table table{directory[d.table_idx]};
+  table.set(d.page_idx, 0);
+  vmm::reload();
+}
+
 vmm::page_table::page_table(uint32_t from) {
   // TODO get flags
   // convert physical address to a virtual address so we can read it