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73 lines
1.6 KiB
C++
73 lines
1.6 KiB
C++
#include <array>
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#include <cstdint>
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extern void kernel_main();
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struct multiboot2
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{
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static constexpr std::uint32_t MAGIC = 0xE85250D6;
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static constexpr std::uint32_t FLAGS = 0;
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static constexpr std::uint32_t LENGTH = 16;
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static constexpr std::uint32_t CHECKSUM = -(MAGIC + FLAGS + LENGTH);
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alignas(8)
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std::uint32_t magic = MAGIC;
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std::uint32_t flags = FLAGS;
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std::uint32_t length = LENGTH;
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std::uint32_t checksum = CHECKSUM;
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} __attribute__((packed));
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struct multiboot2_tag
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{
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alignas(8)
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std::uint16_t id;
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std::uint16_t flags;
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std::uint32_t length;
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std::uint32_t data[];
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} __attribute__((packed));
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__attribute__((section(".multiboot2")))
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multiboot2 multibootHeader;
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__attribute__((section(".multiboot2")))
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multiboot2_tag multibootTagInfoRequest = {
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1, 0, sizeof(multiboot2_tag) + sizeof(std::uint32_t),
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{4}
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};
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__attribute__((section(".multiboot2")))
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multiboot2_tag multibootTagEnd = {
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0, 0, sizeof(multiboot2_tag), {}
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};
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alignas(16)
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std::array<std::uint8_t, 16384> stack;
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extern "C"
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__attribute__((naked))
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void _start()
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{
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asm volatile(R"(
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mov %%eax, multiboot_magic
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mov %%ebx, multiboot_ptr
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mov %0, %%esp
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)" :: "i" (stack.data() + stack.size()));
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extern std::uint32_t __init_array_start;
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extern std::uint32_t __init_array_end;
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auto it = &__init_array_start;
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while (it < &__init_array_end) {
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auto fn = reinterpret_cast<void (*)()>(*it);
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fn();
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++it;
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}
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kernel_main();
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asm volatile("cli");
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for (;;)
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asm volatile("hlt");
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}
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