Luna/kernel/src/fs/MBR.cpp

#include "fs/MBR.h"
#include "Log.h"

namespace MBR
{
    Result<bool> identify(SharedPtr<Device> device)
    {
        // Cannot read a partition table from a character device! Who is even coming up with this silliness?
        if (!device->is_block_device()) return false;

        DiskHeader hdr;
        usize nread = TRY(device->read((u8*)&hdr, 0, sizeof(hdr)));
        check(nread == 512);

        if (hdr.signature[0] != MBR_SIGNATURE_1 || hdr.signature[1] != MBR_SIGNATURE_2) return false;

        for (int i = 0; i < 4; i++)
        {
            const auto& part = hdr.partitions[i];
            if (part.partition_type == 0) continue; // Not active.

            bool bootable = part.attributes & MBR_BOOTABLE;
            kinfoln("mbr: Partition #%d is active: bootable=%d, type=%x, start=%d, sectors=%d", i, bootable,
                    part.partition_type, part.start_lba, part.num_sectors);
        }

        return true;
    }
}