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Kernel: Add support for loading gzip compressed initrd

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This commit is contained in:
Bananymous
2026-04-13 16:36:35 +03:00
parent 0156d06cdc
commit c849293f3d
3 changed files with 299 additions and 110 deletions
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5
kernel/include/kernel/FS/USTARModule.h
View File

@@ -1,12 +1,11 @@
#pragma once
#include <kernel/BootInfo.h>
#include <kernel/FS/FileSystem.h>
#include <kernel/FS/Inode.h>
namespace Kernel
{
bool is_ustar_boot_module(const BootModule&);
BAN::ErrorOr<void> unpack_boot_module_into_filesystem(BAN::RefPtr<FileSystem>, const BootModule&);
BAN::ErrorOr<bool> unpack_boot_module_into_directory(BAN::RefPtr<Inode>, const BootModule&);
}

352
kernel/kernel/FS/USTARModule.cpp
View File

@@ -1,64 +1,239 @@
#include <BAN/ScopeGuard.h>
#include <kernel/FS/USTARModule.h>
#include <kernel/Timer/Timer.h>
#include <LibDEFLATE/Decompressor.h>
#include <tar.h>
namespace Kernel
{
bool is_ustar_boot_module(const BootModule& module)
class DataSource
{
if (module.start % PAGE_SIZE)
public:
DataSource() = default;
virtual ~DataSource() = default;
size_t data_size() const
{
dprintln("ignoring non-page-aligned module");
return false;
return m_data_size;
}
if (module.size < 512)
BAN::ConstByteSpan data()
{
return { m_data_buffer, m_data_size };
}
void pop_data(size_t size)
{
ASSERT(size <= m_data_size);
if (size > 0 && size < m_data_size)
memmove(m_data_buffer, m_data_buffer + size, m_data_size - size);
m_data_size -= size;
m_bytes_produced += size;
}
virtual BAN::ErrorOr<bool> produce_data() = 0;
uint64_t bytes_produced() const
{
return m_bytes_produced;
}
virtual uint64_t bytes_consumed() const = 0;
protected:
uint8_t m_data_buffer[4096];
size_t m_data_size { 0 };
private:
uint64_t m_bytes_produced { 0 };
};
class DataSourceRaw final : public DataSource
{
public:
DataSourceRaw(const BootModule& module)
: m_module(module)
{ }
BAN::ErrorOr<bool> produce_data() override
{
if (m_offset >= m_module.size || m_data_size >= sizeof(m_data_buffer))
return false;
bool has_ustar_signature;
PageTable::with_fast_page(module.start, [&] {
has_ustar_signature = memcmp(PageTable::fast_page_as_ptr(257), "ustar", 5) == 0;
while (m_offset < m_module.size && m_data_size < sizeof(m_data_buffer))
{
const size_t to_copy = BAN::Math::min(
sizeof(m_data_buffer) - m_data_size,
PAGE_SIZE - (m_offset % PAGE_SIZE)
);
PageTable::with_fast_page((m_module.start + m_offset) & PAGE_ADDR_MASK, [&] {
memcpy(m_data_buffer + m_data_size, PageTable::fast_page_as_ptr(m_offset % PAGE_SIZE), to_copy);
});
return has_ustar_signature;
m_data_size += to_copy;
m_offset += to_copy;
}
BAN::ErrorOr<void> unpack_boot_module_into_filesystem(BAN::RefPtr<FileSystem> filesystem, const BootModule& module)
return true;
}
uint64_t bytes_consumed() const override
{
ASSERT(is_ustar_boot_module(module));
return bytes_produced();
}
auto root_inode = filesystem->root_inode();
private:
const BootModule& m_module;
size_t m_offset { 0 };
};
uint8_t* temp_page = static_cast<uint8_t*>(kmalloc(PAGE_SIZE));
if (temp_page == nullptr)
return BAN::Error::from_errno(ENOMEM);
BAN::ScopeGuard _([temp_page] { kfree(temp_page); });
class DataSourceGZip final : public DataSource
{
public:
DataSourceGZip(BAN::UniqPtr<DataSource>&& data_source)
: m_data_source(BAN::move(data_source))
, m_decompressor(LibDEFLATE::StreamType::GZip)
{ }
BAN::ErrorOr<bool> produce_data() override
{
if (m_is_done)
return false;
bool did_produce_data { false };
for (;;)
{
TRY(m_data_source->produce_data());
size_t input_consumed, output_produced;
const auto status = TRY(m_decompressor.decompress(
m_data_source->data(),
input_consumed,
{ m_data_buffer + m_data_size, sizeof(m_data_buffer) - m_data_size },
output_produced
));
m_data_source->pop_data(input_consumed);
m_data_size += output_produced;
if (output_produced)
did_produce_data = true;
switch (status)
{
using DecompStatus = LibDEFLATE::Decompressor::Status;
case DecompStatus::Done:
m_is_done = true;
return did_produce_data;
case DecompStatus::NeedMoreInput:
break;
case DecompStatus::NeedMoreOutput:
return did_produce_data;
}
}
}
uint64_t bytes_consumed() const override
{
return m_data_source->bytes_consumed();
}
private:
BAN::UniqPtr<DataSource> m_data_source;
LibDEFLATE::Decompressor m_decompressor;
bool m_is_done { false };
};
static BAN::ErrorOr<void> unpack_boot_module_into_directory(BAN::RefPtr<Inode> root_inode, DataSource& data_source);
BAN::ErrorOr<bool> unpack_boot_module_into_directory(BAN::RefPtr<Inode> root_inode, const BootModule& module)
{
ASSERT(root_inode->mode().ifdir());
BAN::UniqPtr<DataSource> data_source = TRY(BAN::UniqPtr<DataSourceRaw>::create(module));
bool is_compressed = false;
TRY(data_source->produce_data());
if (data_source->data_size() >= 2 && memcmp(&data_source->data()[0], "\x1F\x8B", 2) == 0)
{
data_source = TRY(BAN::UniqPtr<DataSourceGZip>::create(BAN::move(data_source)));
is_compressed = true;
}
TRY(data_source->produce_data());
if (data_source->data_size() < 512 || memcmp(&data_source->data()[257], "ustar", 5) != 0)
{
dwarnln("Unrecognized initrd format");
return false;
}
const auto module_size_kib = module.size / 1024;
dprintln("unpacking {}.{3} MiB{} initrd",
module_size_kib / 1024, (module_size_kib % 1024) * 1000 / 1024,
is_compressed ? " compressed" : ""
);
const auto unpack_ms1 = SystemTimer::get().ms_since_boot();
TRY(unpack_boot_module_into_directory(root_inode, *data_source));
const auto unpack_ms2 = SystemTimer::get().ms_since_boot();
const auto duration_ms = unpack_ms2 - unpack_ms1;
dprintln("unpacking {}.{3} MiB{} initrd took {}.{3} s",
module_size_kib / 1024, (module_size_kib % 1024) * 1000 / 1024,
is_compressed ? " compressed" : "",
duration_ms / 1000, duration_ms % 1000
);
if (is_compressed)
{
const auto uncompressed_kib = data_source->bytes_produced() / 1024;
dprintln("uncompressed size {}.{3} MiB",
uncompressed_kib / 1024, (uncompressed_kib % 1024) * 1000 / 1024
);
}
return true;
}
BAN::ErrorOr<void> unpack_boot_module_into_directory(BAN::RefPtr<Inode> root_inode, DataSource& data_source)
{
BAN::String next_file_name;
BAN::String next_link_name;
size_t offset = 0;
while (offset + 512 <= module.size)
{
size_t file_size = 0;
mode_t file_mode = 0;
uid_t file_uid = 0;
gid_t file_gid = 0;
uint8_t file_type = 0;
char file_path[100 + 1 + 155 + 1] {};
constexpr uint32_t print_interval_ms = 1000;
auto next_print_ms = SystemTimer::get().ms_since_boot() + print_interval_ms;
PageTable::with_fast_page((module.start + offset) & PAGE_ADDR_MASK, [&] {
const size_t page_off = offset % PAGE_SIZE;
while (TRY(data_source.produce_data()), data_source.data_size() >= 512)
{
if (SystemTimer::get().ms_since_boot() >= next_print_ms)
{
const auto kib_consumed = data_source.bytes_consumed() / 1024;
const auto kib_produced = data_source.bytes_produced() / 1024;
if (kib_consumed == kib_produced)
{
dprintln(" ... {}.{3} MiB",
kib_consumed / 1024, (kib_consumed % 1024) * 1000 / 1024
);
}
else
{
dprintln(" ... {}.{3} MiB ({}.{3} MiB)",
kib_consumed / 1024, (kib_consumed % 1024) * 1000 / 1024,
kib_produced / 1024, (kib_produced % 1024) * 1000 / 1024
);
}
next_print_ms = SystemTimer::get().ms_since_boot() + print_interval_ms;
}
const auto parse_octal =
[page_off](size_t offset, size_t length) -> size_t
[&data_source](size_t offset, size_t length) -> size_t
{
size_t result = 0;
for (size_t i = 0; i < length; i++)
{
const char ch = PageTable::fast_page_as<char>(page_off + offset + i);
const char ch = data_source.data()[offset + i];
if (ch == '\0')
break;
result = (result * 8) + (ch - '0');
@@ -66,29 +241,22 @@ namespace Kernel
return result;
};
if (memcmp(PageTable::fast_page_as_ptr(page_off + 257), "ustar", 5)) {
file_size = SIZE_MAX;
return;
}
if (memcmp(&data_source.data()[257], "ustar", 5) != 0)
break;
memcpy(file_path, PageTable::fast_page_as_ptr(page_off + 345), 155);
char file_path[100 + 1 + 155 + 1];
memcpy(file_path, &data_source.data()[345], 155);
const size_t prefix_len = strlen(file_path);
file_path[prefix_len] = '/';
memcpy(file_path + prefix_len + 1, PageTable::fast_page_as_ptr(page_off), 100);
memcpy(file_path + prefix_len + 1, &data_source.data()[0], 100);
file_mode = parse_octal(100, 8);
file_uid = parse_octal(108, 8);
file_gid = parse_octal(116, 8);
file_size = parse_octal(124, 12);
file_type = PageTable::fast_page_as<char>(page_off + 156);
});
mode_t file_mode = parse_octal(100, 8);
const uid_t file_uid = parse_octal(108, 8);
const gid_t file_gid = parse_octal(116, 8);
const size_t file_size = parse_octal(124, 12);
const uint8_t file_type = data_source.data()[156];
if (file_size == SIZE_MAX)
break;
if (offset + 512 + file_size > module.size)
break;
auto parent_inode = filesystem->root_inode();
auto parent_inode = root_inode;
auto file_path_parts = TRY(BAN::StringView(next_file_name.empty() ? file_path : next_file_name.sv()).split('/'));
for (size_t i = 0; i < file_path_parts.size() - 1; i++)
@@ -111,27 +279,33 @@ namespace Kernel
auto file_name_sv = file_path_parts.back();
bool did_consume_data = false;
if (file_type == 'L' || file_type == 'K')
{
auto& target = (file_type == 'L') ? next_file_name : next_link_name;
TRY(target.resize(file_size));
auto& target_str = (file_type == 'L') ? next_file_name : next_link_name;
TRY(target_str.resize(file_size));
data_source.pop_data(512);
size_t nwritten = 0;
while (nwritten < file_size)
{
const paddr_t paddr = module.start + offset + 512 + nwritten;
PageTable::with_fast_page(paddr & PAGE_ADDR_MASK, [&] {
memcpy(temp_page, PageTable::fast_page_as_ptr(), PAGE_SIZE);
});
TRY(data_source.produce_data());
if (data_source.data_size() == 0)
return {};
const size_t page_off = paddr % PAGE_SIZE;
const size_t to_write = BAN::Math::min(file_size - nwritten, PAGE_SIZE - page_off);
memcpy(target.data() + nwritten, temp_page + page_off, to_write);
nwritten += to_write;
const size_t to_copy = BAN::Math::min(data_source.data_size(), file_size - nwritten);
memcpy(target_str.data() + nwritten, data_source.data().data(), to_copy);
nwritten += to_copy;
data_source.pop_data(to_copy);
}
while (!target.empty() && target.back() == '\0')
target.pop_back();
did_consume_data = true;
while (!target_str.empty() && target_str.back() == '\0')
target_str.pop_back();
}
else if (file_type == DIRTYPE)
{
@@ -149,14 +323,11 @@ namespace Kernel
link_name = next_link_name.sv();
else
{
const paddr_t paddr = module.start + offset;
PageTable::with_fast_page(paddr & PAGE_ADDR_MASK, [&] {
memcpy(link_buffer, PageTable::fast_page_as_ptr((paddr % PAGE_SIZE) + 157), 100);
});
memcpy(link_buffer, &data_source.data()[157], 100);
link_name = link_buffer;
}
auto target_inode = filesystem->root_inode();
auto target_inode = root_inode;
auto link_path_parts = TRY(link_name.split('/'));
for (const auto part : link_path_parts)
@@ -188,10 +359,7 @@ namespace Kernel
link_name = next_link_name.sv();
else
{
const paddr_t paddr = module.start + offset;
PageTable::with_fast_page(paddr & PAGE_ADDR_MASK, [&] {
memcpy(link_buffer, PageTable::fast_page_as_ptr((paddr % PAGE_SIZE) + 157), 100);
});
memcpy(link_buffer, &data_source.data()[157], 100);
link_name = link_buffer;
}
@@ -203,26 +371,26 @@ namespace Kernel
{
if (auto ret = parent_inode->create_file(file_name_sv, file_mode, file_uid, file_gid); ret.is_error())
dwarnln("failed to create file '{}': {}", file_name_sv, ret.error());
else
{
if (file_size)
else if (file_size)
{
auto inode = TRY(parent_inode->find_inode(file_name_sv));
data_source.pop_data(512);
size_t nwritten = 0;
while (nwritten < file_size)
{
const paddr_t paddr = module.start + offset + 512 + nwritten;
PageTable::with_fast_page(paddr & PAGE_ADDR_MASK, [&] {
memcpy(temp_page, PageTable::fast_page_as_ptr(), PAGE_SIZE);
});
TRY(data_source.produce_data());
ASSERT(data_source.data_size() > 0); // what to do?
const size_t page_off = paddr % PAGE_SIZE;
const size_t to_write = BAN::Math::min(file_size - nwritten, PAGE_SIZE - page_off);
TRY(inode->write(nwritten, { temp_page + page_off, to_write }));
const size_t to_write = BAN::Math::min(file_size - nwritten, data_source.data_size());
TRY(inode->write(nwritten, data_source.data().slice(0, to_write)));
nwritten += to_write;
data_source.pop_data(to_write);
}
}
did_consume_data = true;
}
}
@@ -232,9 +400,27 @@ namespace Kernel
next_link_name.clear();
}
offset += 512 + file_size;
if (auto rem = offset % 512)
offset += 512 - rem;
if (!did_consume_data)
{
data_source.pop_data(512);
size_t consumed = 0;
while (consumed < file_size)
{
TRY(data_source.produce_data());
if (data_source.data_size() == 0)
return {};
data_source.pop_data(BAN::Math::min(file_size - consumed, data_source.data_size()));
}
}
if (const auto rem = file_size % 512)
{
TRY(data_source.produce_data());
if (data_source.data_size() < rem)
return {};
data_source.pop_data(512 - rem);
}
}
return {};

12
kernel/kernel/FS/VirtualFileSystem.cpp
View File

@@ -61,18 +61,22 @@ namespace Kernel
if (filesystem_or_error.is_error())
panic("Failed to create fallback filesystem: {}", filesystem_or_error.error());
dprintln("Loading fallback filesystem from {} modules", g_boot_info.modules.size());
dprintln("Trying to load fallback filesystem from {} modules", g_boot_info.modules.size());
auto filesystem = BAN::RefPtr<FileSystem>::adopt(filesystem_or_error.release_value());
bool loaded_initrd = false;
for (const auto& module : g_boot_info.modules)
{
if (!is_ustar_boot_module(module))
continue;
if (auto ret = unpack_boot_module_into_filesystem(filesystem, module); ret.is_error())
if (auto ret = unpack_boot_module_into_directory(filesystem->root_inode(), module); ret.is_error())
dwarnln("Failed to unpack boot module: {}", ret.error());
else
loaded_initrd |= ret.value();
}
if (!loaded_initrd)
panic("Could not load initrd from any boot module :(");
return filesystem;
}