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#include "textoutput.hpp"
#include <cstdint>
extern TextOutput& term;
struct multiboot2_tag
{
alignas(8)
std::uint16_t id;
std::uint16_t flags;
std::uint32_t length;
std::uint32_t data[1];
} __attribute__((packed));
template<int N>
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;
multiboot2_tag tags[N];
} __attribute__((packed));
__attribute__((section(".multiboot2")))
multiboot2 multibootHeader = {
.tags = {
{
1, 0, sizeof(multiboot2_tag) + sizeof(std::uint32_t),
{4}
},
{
0, 0, 8, {}
}
}
};
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()
{
if (multiboot_magic != 0x36d76289) {
term.write("Not multiboot!");
return false;
}
term.write("Found multiboot headers: ");
auto ptr = multiboot_ptr + 2;
while (ptr[0] != 0 && ptr[1] != 8) {
term.write(ptr[0]);
term.write(", ");
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);
next += ptr[1];
next = (next + 7) & ~7;
ptr = reinterpret_cast<std::uint32_t *>(next);
}
term.write('\n');
return true;
}
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