From e7ccb96aecae7b231fb05818d7e45a767aebc31d Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Wed, 18 Mar 2026 17:18:37 +0100
Subject: kstd: introduce strong type for memory amounts

---
 arch/x86_64/include/arch/memory/page_table.hpp |  3 ++-
 arch/x86_64/kapi/memory.cpp                    | 17 ++++++++++-------
 arch/x86_64/src/memory/kernel_mapper.cpp       |  9 ++++++---
 3 files changed, 18 insertions(+), 11 deletions(-)

(limited to 'arch')

diff --git a/arch/x86_64/include/arch/memory/page_table.hpp b/arch/x86_64/include/arch/memory/page_table.hpp
index 2889d38..3cbb0af 100644
--- a/arch/x86_64/include/arch/memory/page_table.hpp
+++ b/arch/x86_64/include/arch/memory/page_table.hpp
@@ -4,6 +4,7 @@
 #include "kapi/memory.hpp"
 
 #include <kstd/ext/bitfield_enum>
+#include <kstd/units>
 
 #include <array>
 #include <cstddef>
@@ -116,7 +117,7 @@ namespace arch::memory
     };
 
     //! The maximum number of entries in this table.
-    constexpr auto static entry_count{kapi::memory::page::size / sizeof(entry)};
+    constexpr auto static entry_count{kapi::memory::page::size / kstd::units::bytes{sizeof(entry)}};
 
     //! Get the entry at the given index.
     //!
diff --git a/arch/x86_64/kapi/memory.cpp b/arch/x86_64/kapi/memory.cpp
index 07e7465..5f12e5c 100644
--- a/arch/x86_64/kapi/memory.cpp
+++ b/arch/x86_64/kapi/memory.cpp
@@ -13,6 +13,7 @@
 #include "arch/memory/region_allocator.hpp"
 
 #include <kstd/print>
+#include <kstd/units>
 
 #include <multiboot2/constants.hpp>
 #include <multiboot2/information.hpp>
@@ -28,6 +29,8 @@
 #include <span>
 #include <utility>
 
+using namespace kstd::units_literals;
+
 namespace kapi::memory
 {
 
@@ -46,7 +49,7 @@ namespace kapi::memory
       }
 
       auto const & mbi = boot::bootstrap_information.mbi;
-      auto mbi_span = std::span{std::bit_cast<std::byte *>(mbi), mbi->size_bytes()};
+      auto mbi_span = std::span{std::bit_cast<std::byte *>(mbi), static_cast<std::size_t>(mbi->size())};
       auto image_span = std::span{&arch::boot::_start_physical, &arch::boot::_end_physical};
 
       return arch::memory::region_allocator::memory_information{
@@ -107,10 +110,10 @@ namespace kapi::memory
     [[maybe_unused]] auto remap_multiboot_information(page_mapper & mapper) -> void
     {
       auto mbi_base = std::bit_cast<std::uintptr_t>(boot::bootstrap_information.mbi);
-      auto mbi_size = boot::bootstrap_information.mbi->size_bytes();
+      auto mbi_size = boot::bootstrap_information.mbi->size();
       auto mbi_physical_start = physical_address{mbi_base & ~std::bit_cast<std::uintptr_t>(&arch::boot::TEACHOS_VMA)};
       auto mbi_virtual_start = linear_address{mbi_base};
-      auto mbi_block_count = (mbi_size + frame::size - 1) / frame::size;
+      auto mbi_block_count = (mbi_size + frame::size - 1_B) / frame::size;
 
       for (auto i = 0uz; i < mbi_block_count; ++i)
       {
@@ -126,8 +129,8 @@ namespace kapi::memory
         auto module_physical_start = physical_address{module.start_address};
         auto module_virtual_start =
             linear_address{module.start_address + std::bit_cast<std::uintptr_t>(&arch::boot::TEACHOS_VMA)};
-        auto module_size = module.end_address - module.start_address;
-        auto module_block_count = (module_size + frame::size - 1) / frame::size;
+        auto module_size = static_cast<kstd::units::bytes>(module.end_address - module.start_address);
+        auto module_block_count = (module_size + frame::size - 1_B) / frame::size;
 
         for (auto i = 0uz; i < module_block_count; ++i)
         {
@@ -147,7 +150,7 @@ namespace kapi::memory
                                  }))
       {
         auto start = frame::containing(physical_address{region.base});
-        auto count = region.size_in_B / page::size;
+        auto count = kstd::units::bytes{region.size_in_B} / page::size;
         new_allocator.release_many({start, count});
       }
 
@@ -167,7 +170,7 @@ namespace kapi::memory
                             [&](auto frame) { new_allocator.mark_used(frame); });
 
       auto mbi_base = std::bit_cast<std::uintptr_t>(boot::bootstrap_information.mbi);
-      auto mbi_size = boot::bootstrap_information.mbi->size_bytes();
+      auto mbi_size = boot::bootstrap_information.mbi->size();
       auto mbi_address = physical_address{mbi_base & ~std::bit_cast<std::uintptr_t>(&arch::boot::TEACHOS_VMA)};
       auto mbi_start = frame::containing(mbi_address);
       auto mbi_end = frame::containing(mbi_address + mbi_size) + 1;
diff --git a/arch/x86_64/src/memory/kernel_mapper.cpp b/arch/x86_64/src/memory/kernel_mapper.cpp
index e5bb7f8..ced8a14 100644
--- a/arch/x86_64/src/memory/kernel_mapper.cpp
+++ b/arch/x86_64/src/memory/kernel_mapper.cpp
@@ -6,6 +6,7 @@
 #include "arch/boot/ld.hpp"
 
 #include <kstd/print>
+#include <kstd/units>
 
 #include <elf/format.hpp>
 #include <elf/section_header.hpp>
@@ -19,13 +20,14 @@
 #include <string_view>
 #include <utility>
 
+using namespace std::string_view_literals;
+using namespace kstd::units_literals;
+
 namespace arch::memory
 {
 
   namespace
   {
-    using namespace std::string_view_literals;
-
     constexpr auto static ignored_section_prefixes = std::array{
       ".boot_"sv,
     };
@@ -71,7 +73,8 @@ namespace arch::memory
   auto kernel_mapper::map_section(section_header_type const & section, std::string_view name,
                                   kapi::memory::page_mapper & mapper) -> void
   {
-    auto number_of_pages = (section.size + (kapi::memory::page::size - 1)) / kapi::memory::page::size;
+    auto number_of_pages =
+        (kstd::units::bytes{section.size} + (kapi::memory::page::size - 1_B)) / kapi::memory::page::size;
     auto linear_start_address = kapi::memory::linear_address{section.virtual_load_address};
     auto physical_start_address = kapi::memory::physical_address{section.virtual_load_address & ~m_kernel_load_base};
 
-- 
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