Convert MemoryMapIterator to Option

kernel/src/memory/MemoryManager.cpp

@@ -105,10 +105,12 @@ namespace MemoryManager
         // there's no point in continuing.
         auto bitmap_pages = g_frame_bitmap.size_in_bytes() / ARCH_PAGE_SIZE;
 
-        auto virtual_bitmap_base = KernelVM::alloc_several_pages(bitmap_pages).release_value();
+        auto virtual_bitmap_base =
+            KernelVM::alloc_several_pages(bitmap_pages)
+                .expect_value("Unable to allocate virtual memory for the physical frame bitmap, cannot continue");
         map_frames_at(virtual_bitmap_base, (u64)g_frame_bitmap.location(), bitmap_pages,
                       MMU::ReadWrite | MMU::NoExecute)
-            .release_value();
+            .expect_value("Unable to map the physical frame bitmap to virtual memory, cannot continue");
 
         g_frame_bitmap.initialize((void*)virtual_bitmap_base, g_frame_bitmap.size_in_bytes());
     }
@@ -292,7 +294,7 @@ namespace MemoryManager
     {
         auto rc = MMU::get_flags(address);
         if (rc.has_error()) return false;
-        if (rc.release_value() & MMU::ReadWrite) return true;
+        if (rc.value() & MMU::ReadWrite) return true;
         return false;
     }
 

kernel/src/memory/MemoryMap.cpp

@@ -35,13 +35,13 @@ void MemoryMapIterator::rewind()
     m_cur_ent = 0;
 }
 
-Result<MemoryMapEntry> MemoryMapIterator::at(usize index) const
+Option<MemoryMapEntry> MemoryMapIterator::at(usize index) const
 {
-    if (index >= m_mmap_entries) return err(ERANGE);
+    if (index >= m_mmap_entries) return {};
     return memory_map_entry_from_mmapent(m_base_ent + index);
 }
 
-Result<MemoryMapEntry> MemoryMapIterator::next()
+Option<MemoryMapEntry> MemoryMapIterator::next()
 {
     return at(m_cur_ent++);
 }
@@ -63,7 +63,7 @@ MemoryMapEntry MemoryMapIterator::largest_free()
         }
     }
 
-    return at(largest_index).release_value();
+    return at(largest_index).value();
 }
 
 MemoryMapEntry MemoryMapIterator::highest()
@@ -83,5 +83,5 @@ MemoryMapEntry MemoryMapIterator::highest()
         }
     }
 
-    return at(highest_index).release_value();
+    return at(highest_index).value();
 }

kernel/src/memory/MemoryMap.h

@@ -44,13 +44,13 @@ class MemoryMapIterator
 
     void rewind();
 
-    Result<MemoryMapEntry> next();
+    Option<MemoryMapEntry> next();
 
     MemoryMapEntry largest_free();
 
     MemoryMapEntry highest();
 
-    Result<MemoryMapEntry> at(usize index) const;
+    Option<MemoryMapEntry> at(usize index) const;
 
     usize entries() const
     {

kernel/src/thread/Scheduler.cpp

@@ -24,7 +24,8 @@ namespace Scheduler
         g_idle.ticks_left = 1;
 
         // Map some stack for the idle task
-        u64 idle_stack_vm = MemoryManager::alloc_for_kernel(1, MMU::NoExecute | MMU::ReadWrite).release_value();
+        u64 idle_stack_vm = MemoryManager::alloc_for_kernel(1, MMU::NoExecute | MMU::ReadWrite)
+                                .expect_value("Error while setting up the idle task, cannot continue");
 
         Stack idle_stack{idle_stack_vm, ARCH_PAGE_SIZE};
         g_idle.set_sp(idle_stack.top());