diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt index 4352da53..8be7a6c3 100644 --- a/kernel/CMakeLists.txt +++ b/kernel/CMakeLists.txt @@ -44,6 +44,7 @@ set(SOURCES src/fs/Pipe.cpp src/fs/Mount.cpp src/fs/MBR.cpp + src/fs/GPT.cpp src/fs/tmpfs/FileSystem.cpp src/fs/devices/DeviceRegistry.cpp src/fs/devices/NullDevice.cpp diff --git a/kernel/src/fs/GPT.cpp b/kernel/src/fs/GPT.cpp new file mode 100644 index 00000000..58142faa --- /dev/null +++ b/kernel/src/fs/GPT.cpp @@ -0,0 +1,73 @@ +#include "fs/GPT.h" +#include + +static const u8 null_guid[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; + +namespace GPT +{ + Result identify(SharedPtr device) + { + if (!device->is_block_device()) return false; + + Header header; + // The header is at LBA 1. + usize nread = TRY(device->read((u8*)&header, 1 * GPT_SECTOR_SIZE, sizeof(header))); + check(nread == sizeof(header)); + + if (memcmp(header.signature, GPT_SIGNATURE, GPT_SIGNATURE_LENGTH)) return false; + + kdbgln("gpt: Found GUID partition table on device %s, revision %#.8x, with space for %d partition entries!", + device->device_path().chars(), header.revision, header.num_partitions); + + if (header.revision != GPT_REVISION) + { + kwarnln("gpt: GUID partition table revision not supported!"); + return false; + } + + check(header.hdr_size == 0x5c); + check(header.reserved == 0); + check(header.this_lba == 1); + +#if 0 + const u32 chksum = checksum_gpt(header); + + if (chksum != header.checksum) + { + kwarnln("gpt: Header checksum does not match, %#.8x != %#.8x!", chksum, header.checksum); + return false; + } +#endif + + u64 partition_table_start = header.partition_table_lba * GPT_SECTOR_SIZE; + + u32 partition_index = 0; + + auto* table = TRY(make_array(header.num_partitions)); + auto guard = make_scope_guard([table] { delete[] table; }); + + nread = TRY(device->read((u8*)table, partition_table_start, sizeof(PartitionEntry) * header.num_partitions)); + check(nread == sizeof(PartitionEntry) * header.num_partitions); + + for (u32 i = 0; i < header.num_partitions; i++) + { + PartitionEntry& entry = table[i]; + + if (!memcmp(entry.type_guid, null_guid, 16)) continue; + + kdbgln("gpt: Partition entry #%u is active: start=%lu, end=%lu", i, entry.start_lba, entry.end_lba); + + TRY(MBR::PartitionDevice::create(device, entry.start_lba, entry.end_lba - entry.start_lba, + partition_index++)); + } + + return true; + } + + u32 checksum_gpt(Header header) + { + header.checksum = 0; + + return CRC32::checksum((u8*)&header, 0x5c); + } +} diff --git a/kernel/src/fs/GPT.h b/kernel/src/fs/GPT.h new file mode 100644 index 00000000..800413b4 --- /dev/null +++ b/kernel/src/fs/GPT.h @@ -0,0 +1,43 @@ +#pragma once +#include "fs/MBR.h" + +#define GPT_SIGNATURE "EFI PART" +#define GPT_SIGNATURE_LENGTH 8 +#define GPT_SECTOR_SIZE 512ul +#define GPT_REVISION 0x00010000 + +namespace GPT +{ + struct [[gnu::packed]] Header + { + u8 signature[GPT_SIGNATURE_LENGTH]; + u32 revision; + u32 hdr_size; + u32 checksum; + u32 reserved; + u64 this_lba; + u64 alternate_lba; + u64 first_usable; + u64 last_usable; + u8 guid[16]; + u64 partition_table_lba; + u32 num_partitions; + u32 partition_entry_size; + u32 partition_table_checksum; + char blank[512 - 0x5c]; + }; + + struct [[gnu::packed]] PartitionEntry + { + u8 type_guid[16]; + u8 unique_guid[16]; + u64 start_lba; + u64 end_lba; + u64 attributes; + char partition_name[72]; // Could be more or less, see Header::partition_entry_size - 0x38 for the actual size. + }; + + Result identify(SharedPtr device); + + u32 checksum_gpt(Header header); +} diff --git a/kernel/src/fs/MBR.cpp b/kernel/src/fs/MBR.cpp index 5be1d280..0aad45d4 100644 --- a/kernel/src/fs/MBR.cpp +++ b/kernel/src/fs/MBR.cpp @@ -1,5 +1,6 @@ #include "fs/MBR.h" #include "Log.h" +#include "fs/GPT.h" #include static Result create_partition_name(SharedPtr host_device, u32 partition_index) @@ -60,6 +61,12 @@ namespace MBR u32 partition_index = 0; + for (int i = 0; i < 4; i++) + { + const auto& part = hdr.partitions[i]; + if (part.partition_type == 0xee) return GPT::identify(device); + } + for (int i = 0; i < 4; i++) { const auto& part = hdr.partitions[i]; diff --git a/libluna/CMakeLists.txt b/libluna/CMakeLists.txt index 51190b11..cb1e3b85 100644 --- a/libluna/CMakeLists.txt +++ b/libluna/CMakeLists.txt @@ -4,6 +4,7 @@ file(GLOB HEADERS include/luna/*.h) set(FREESTANDING_SOURCES ${HEADERS} + src/CRC32.cpp src/Format.cpp src/Sort.cpp src/NumberParsing.cpp diff --git a/libluna/include/luna/CRC32.h b/libluna/include/luna/CRC32.h new file mode 100644 index 00000000..8b019756 --- /dev/null +++ b/libluna/include/luna/CRC32.h @@ -0,0 +1,7 @@ +#pragma once +#include + +namespace CRC32 +{ + u32 checksum(const u8* data, usize size); +} diff --git a/libluna/src/CRC32.cpp b/libluna/src/CRC32.cpp new file mode 100644 index 00000000..31965739 --- /dev/null +++ b/libluna/src/CRC32.cpp @@ -0,0 +1,52 @@ +#include +#include + +static const u32 crc_table[] = { + 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, + 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, + 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, + 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, + 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, + 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, + 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, + 0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, + 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, + 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, + 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, + 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, + 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, + 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, + 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, + 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, + 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, + 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e, + 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, + 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, + 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, + 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, + 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, + 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, + 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, + 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, + 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, + 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, + 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d +}; + +namespace CRC32 +{ + // FIXME: This shouldn't return 0xffffffff when there are 4 zeros in a row somewhere in the data, right? That's what + // happens to the GPT header. (other CRC32 implementations don't seem to have this problem) + u32 checksum(const u8* data, usize size) + { + u32 crc = 0xffffffffu; + + for (usize i = 0; i < size; i++) + { + const u32 index = (crc & data[i]) & 0xff; + crc = (crc >> 8) ^ (crc_table[index]); + } + + return ~crc; + } +}