acpi detection

1 files changed, 50 insertions, 1 deletions

diff --git a/multiboot.cpp b/multiboot.cpp
index 0c34984..0a30938 100644
--- a/multiboot.cpp
+++ b/multiboot.cpp
@@ -4,11 +4,50 @@
 
 extern TextOutput& term;
 
+struct multiboot2
+{
+    static constexpr std::uint32_t MAGIC    = 0xE85250D6;
+    static constexpr std::uint32_t FLAGS    = 0;
+    static constexpr std::uint32_t LENGTH   = 16;
+    static constexpr std::uint32_t CHECKSUM = -(MAGIC + FLAGS + LENGTH);
+
+    alignas(8)
+    std::uint32_t magic = MAGIC;
+    std::uint32_t flags = FLAGS;
+    std::uint32_t length = LENGTH;
+    std::uint32_t checksum = CHECKSUM;
+} __attribute__((packed));
+
+struct multiboot2_tag
+{
+    alignas(8)
+    std::uint16_t id;
+    std::uint16_t flags;
+    std::uint32_t length;
+    std::uint32_t data[];
+} __attribute__((packed));
+
+__attribute__((section(".multiboot2")))
+multiboot2 multibootHeader;
+
+__attribute__((section(".multiboot2")))
+multiboot2_tag multibootTagInfoRequest = {
+    1, 0, sizeof(multiboot2_tag) + sizeof(std::uint32_t),
+    {4}
+};
+
+__attribute__((section(".multiboot2")))
+multiboot2_tag multibootTagEnd = {
+    0, 0, sizeof(multiboot2_tag), {}
+};
+
 std::uint32_t multiboot_magic;
 std::uint32_t *multiboot_ptr;
 
 std::uint32_t lowerMem = 0;
 std::uint32_t upperMem = 0;
+std::uint32_t *acpiRsdp = nullptr;
+std::uint32_t *acpiRsdpV2 = nullptr;
 
 bool multiboot_initialize()
 {
@@ -24,9 +63,19 @@ bool multiboot_initialize()
         term.write(ptr[0]);
         term.write(", ");
 
-        if (ptr[0] == 4) {
+        switch (ptr[0]) {
+        case 4:
             lowerMem = ptr[2] * 1024;
             upperMem = ptr[3] * 1024;
+            break;
+        case 14:
+            acpiRsdp = ptr + 2;
+            break;
+        case 15:
+            acpiRsdpV2 = ptr + 2;
+            break;
+        default:
+            break;
         }
     
         auto next = reinterpret_cast<std::uintptr_t>(ptr);