WIP: paging and better malloc.

targets/_any/include/drivers/usb.hpp

@@ -0,0 +1,17 @@
+
+#pragma once
+
+#if !defined(BAD_APPLE_OS_DRIVERS_USB_HPP_INCLUDED)
+#define BAD_APPLE_OS_DRIVERS_USB_HPP_INCLUDED
+
+namespace baos::pci
+{
+struct Header;
+}
+
+namespace baos::usb
+{
+[[nodiscard]] bool initController(const pci::Header& pciHeader) noexcept;
+}
+
+#endif // !defined(BAD_APPLE_OS_DRIVERS_USB_HPP_INCLUDED)

targets/_any/include/os/memory.hpp

@@ -0,0 +1,72 @@
+
+#pragma once
+
+#if !defined(BAD_APPLE_OS_OS_MEMORY_HPP_INCLUDED)
+#define BAD_APPLE_OS_OS_MEMORY_HPP_INCLUDED
+
+#include <bit>
+#include <cstdint>
+#include <span>
+
+extern "C" int gKernelStart;
+extern "C" int gKernelEnd;
+
+namespace baos
+{
+struct PageTableEntry
+{
+    bool present : 1;
+    bool writable : 1;
+    bool user : 1;
+    bool writeThrough : 1;
+    bool cacheDisabled : 1;
+    bool accessed : 1;
+    bool dirty : 1;
+    bool pageSize : 1;
+    bool global : 1;
+    std::uint8_t avl : 3;
+    std::uint64_t address : 40;
+    std::uint16_t avl2 : 11;
+    bool executeDisable : 1;
+};
+
+enum class MemoryType
+{
+    USABLE,
+    UNUSABLE,
+    MMIO,
+    RESERVED
+};
+
+struct MemoryRange
+{
+    std::uint64_t pageBase;
+    std::uint64_t numPages;
+    MemoryType type = MemoryType::USABLE;
+
+    MemoryRange& operator=(const MemoryRange&) noexcept = default;
+    bool operator<(const MemoryRange& other) const noexcept
+    {
+        return pageBase < other.pageBase;
+    }
+};
+
+void setupPaging(std::span<const MemoryRange> memoryRanges) noexcept;
+[[nodiscard]] const char* memoryTypeName(MemoryType type) noexcept;
+
+[[nodiscard]] void* allocatePages(unsigned numConsecutive) noexcept;
+[[nodiscard]] inline void* allocatePage() noexcept { return allocatePages(1); }
+
+void setupIdentityPaging(std::uint64_t page) noexcept;
+void setupIdentityPaging2M(std::uint64_t page) noexcept;
+void setupIdentityPaging(std::uint64_t firstPage, std::uint64_t lastPage) noexcept;
+
+inline void identityMapRegion(void* start, std::size_t bytes) noexcept
+{
+    std::uint64_t firstPage = std::bit_cast<std::uint64_t>(start) / 4096;
+    std::uint64_t lastPage = std::bit_cast<std::uint64_t>(static_cast<std::uint8_t*>(start) + bytes) / 4096 + 1;
+    setupIdentityPaging(firstPage, lastPage);
+}
+}
+
+#endif // !defined(BAD_APPLE_OS_OS_MEMORY_HPP_INCLUDED)