1 files changed, 109 insertions, 0 deletions
diff --git a/src/kernel/block.C b/src/kernel/block.C
new file mode 100644
index 000000000..25157dac5
--- /dev/null
+++ b/src/kernel/block.C
@@ -0,0 +1,109 @@
+#include <limits.h>
+#include <assert.h>
+
+#include <kernel/block.H>
+#include <kernel/spte.H>
+#include <kernel/vmmmgr.H>
+#include <kernel/ptmgr.H>
+
+Block::~Block()
+{
+    // Release shadow PTE array.
+    delete[] iv_ptes;
+
+    // Delete next block in the chain.
+    if (iv_nextBlock)
+    {
+        delete iv_nextBlock;
+    }
+}
+
+void Block::init()
+{
+    // Create a shadow PTE for each page.
+    iv_ptes = new ShadowPTE[iv_size / PAGESIZE];
+}
+
+ShadowPTE* Block::getPTE(uint64_t i_addr) const
+{
+    return &iv_ptes[(i_addr - iv_baseAddr) / PAGESIZE];
+};
+
+bool Block::handlePageFault(task_t* i_task, uint64_t i_addr)
+{
+    // Check containment, call down chain if address isn't in this block.
+    if (!isContained(i_addr))
+    {
+        return (iv_nextBlock ?
+                    false : iv_nextBlock->handlePageFault(i_task, i_addr));
+    }
+
+    ShadowPTE* pte = getPTE(i_addr);
+
+    if (!pte->isPresent())
+    {
+        // TODO.  Needs swapping support.
+        return false;
+    }
+
+    if (pte->getPage() == 0)
+    {
+        return false;
+    }
+
+    // Add page table entry.
+    PageTableManager::addEntry(
+            (i_addr / PAGESIZE) * PAGESIZE,
+            pte->getPage(),
+            (pte->isExecutable() ? VmmManager::RO_EXE_ACCESS :
+                (pte->isWritable() ? VmmManager::NORMAL_ACCESS :
+                                     VmmManager::READ_O_ACCESS)));
+
+    return true;
+
+}
+
+void Block::setPhysicalPage(uint64_t i_vAddr, uint64_t i_pAddr,
+                            VmmManager::ACCESS_TYPES i_access)
+{
+    // Check containment, call down chain if address isn't in this block.
+    if (!isContained(i_vAddr))
+    {
+        if (iv_nextBlock)
+        {
+            iv_nextBlock->setPhysicalPage(i_vAddr, i_pAddr, i_access);
+        }
+        else
+        {
+            // No block owns this address.  Code bug.
+            kassert(iv_nextBlock);
+        }
+        return;
+    }
+
+    // Create virtual to physical mapping.
+    ShadowPTE* pte = getPTE(i_vAddr);
+    pte->setPageAddr(i_pAddr);
+    pte->setPresent(true);
+    switch(i_access)
+    {
+        case VmmManager::READ_O_ACCESS:
+            pte->setExecutable(false);
+            pte->setWritable(false);
+            break;
+
+        case VmmManager::NORMAL_ACCESS:
+            pte->setExecutable(false);
+            pte->setWritable(true);
+            break;
+
+        case VmmManager::RO_EXE_ACCESS:
+            pte->setExecutable(true);
+            pte->setWritable(false);
+            break;
+
+        default:
+            kassert(false);
+            break;
+    }
+}