banan-os/kernel/kernel/ACPI.cpp

255 lines
6.5 KiB
C++

#include <BAN/ScopeGuard.h>
#include <BAN/StringView.h>
#include <kernel/ACPI.h>
#include <kernel/Memory/PageTable.h>
#include <lai/core.h>
#define RSPD_SIZE 20
#define RSPDv2_SIZE 36
namespace Kernel
{
struct RSDP
{
uint8_t signature[8];
uint8_t checksum;
uint8_t oemid[6];
uint8_t revision;
uint32_t rsdt_address;
// only in revision >= 2
uint32_t length;
uint64_t xsdt_address;
uint8_t extended_checksum;
uint8_t reserved[3];
};
struct RSDT : public ACPI::SDTHeader
{
uint32_t entries[];
} __attribute__((packed));
struct XSDT : public ACPI::SDTHeader
{
uint64_t entries[];
} __attribute__((packed));
static ACPI* s_instance = nullptr;
BAN::ErrorOr<void> ACPI::initialize()
{
ASSERT(s_instance == nullptr);
s_instance = new ACPI;
if (s_instance == nullptr)
return BAN::Error::from_errno(ENOMEM);
TRY(s_instance->initialize_impl());
lai_create_namespace();
return {};
}
ACPI& ACPI::get()
{
ASSERT(s_instance != nullptr);
return *s_instance;
}
static bool is_rsdp(uintptr_t rsdp_addr)
{
const RSDP* rsdp = (const RSDP*)rsdp_addr;
if (memcmp(rsdp->signature, "RSD PTR ", 8) != 0)
return false;
{
uint8_t checksum = 0;
for (uint32_t i = 0; i < RSPD_SIZE; i++)
checksum += ((const uint8_t*)rsdp)[i];
if (checksum != 0)
return false;
}
if (rsdp->revision == 2)
{
uint8_t checksum = 0;
for (uint32_t i = 0; i < RSPDv2_SIZE; i++)
checksum += ((const uint8_t*)rsdp)[i];
if (checksum != 0)
return false;
}
return true;
}
static const RSDP* locate_rsdp()
{
// FIXME: add this back
#if 0
// Check the multiboot headers
if (auto* rsdp_new = (multiboot2_rsdp_tag_t*)multiboot2_find_tag(MULTIBOOT2_TAG_NEW_RSDP))
return (const RSDP*)rsdp_new->data;
if (auto* rsdp_old = (multiboot2_rsdp_tag_t*)multiboot2_find_tag(MULTIBOOT2_TAG_OLD_RSDP))
return (const RSDP*)rsdp_old->data;
#endif
// Look in main BIOS area below 1 MB
for (uintptr_t addr = P2V(0x000E0000); addr < P2V(0x000FFFFF); addr += 16)
if (is_rsdp(addr))
return (const RSDP*)addr;
return nullptr;
}
static bool is_valid_std_header(const ACPI::SDTHeader* header)
{
uint8_t sum = 0;
for (uint32_t i = 0; i < header->length; i++)
sum += ((uint8_t*)header)[i];
return sum == 0;
}
BAN::ErrorOr<void> ACPI::initialize_impl()
{
const RSDP* rsdp = locate_rsdp();
if (rsdp == nullptr)
return BAN::Error::from_error_code(ErrorCode::ACPI_NoRootSDT);
lai_set_acpi_revision(rsdp->revision);
uint32_t root_entry_count = 0;
if (rsdp->revision >= 2)
{
PageTable::map_fast_page(rsdp->xsdt_address & PAGE_ADDR_MASK);
auto& xsdt = PageTable::fast_page_as<const XSDT>(rsdp->xsdt_address % PAGE_SIZE);
BAN::ScopeGuard _([] { PageTable::unmap_fast_page(); });
if (memcmp(xsdt.signature, "XSDT", 4) != 0)
return BAN::Error::from_error_code(ErrorCode::ACPI_RootInvalid);
if (!is_valid_std_header(&xsdt))
return BAN::Error::from_error_code(ErrorCode::ACPI_RootInvalid);
m_header_table_paddr = rsdp->xsdt_address + offsetof(XSDT, entries);
m_entry_size = 8;
root_entry_count = (xsdt.length - sizeof(SDTHeader)) / 8;
}
else
{
PageTable::map_fast_page(rsdp->rsdt_address & PAGE_ADDR_MASK);
auto& rsdt = PageTable::fast_page_as<const RSDT>(rsdp->rsdt_address % PAGE_SIZE);
BAN::ScopeGuard _([] { PageTable::unmap_fast_page(); });
if (memcmp(rsdt.signature, "RSDT", 4) != 0)
return BAN::Error::from_error_code(ErrorCode::ACPI_RootInvalid);
if (!is_valid_std_header(&rsdt))
return BAN::Error::from_error_code(ErrorCode::ACPI_RootInvalid);
m_header_table_paddr = rsdp->rsdt_address + offsetof(RSDT, entries);
m_entry_size = 4;
root_entry_count = (rsdt.length - sizeof(SDTHeader)) / 4;
}
size_t needed_pages = range_page_count(m_header_table_paddr, root_entry_count * m_entry_size);
m_header_table_vaddr = PageTable::kernel().reserve_free_contiguous_pages(needed_pages, KERNEL_OFFSET);
ASSERT(m_header_table_vaddr);
m_header_table_vaddr += m_header_table_paddr % PAGE_SIZE;
PageTable::kernel().map_range_at(
m_header_table_paddr & PAGE_ADDR_MASK,
m_header_table_vaddr & PAGE_ADDR_MASK,
needed_pages * PAGE_SIZE,
PageTable::Flags::Present
);
auto map_header =
[](paddr_t header_paddr) -> vaddr_t
{
PageTable::map_fast_page(header_paddr & PAGE_ADDR_MASK);
size_t header_length = PageTable::fast_page_as<SDTHeader>(header_paddr % PAGE_SIZE).length;
PageTable::unmap_fast_page();
size_t needed_pages = range_page_count(header_paddr, header_length);
vaddr_t page_vaddr = PageTable::kernel().reserve_free_contiguous_pages(needed_pages, KERNEL_OFFSET);
ASSERT(page_vaddr);
PageTable::kernel().map_range_at(
header_paddr & PAGE_ADDR_MASK,
page_vaddr,
needed_pages * PAGE_SIZE,
PageTable::Flags::Present
);
auto* header = (SDTHeader*)(page_vaddr + (header_paddr % PAGE_SIZE));
if (!is_valid_std_header(header))
{
PageTable::kernel().unmap_range(page_vaddr, needed_pages * PAGE_SIZE);
return 0;
}
return page_vaddr + (header_paddr % PAGE_SIZE);
};
for (uint32_t i = 0; i < root_entry_count; i++)
{
paddr_t header_paddr = (m_entry_size == 4) ?
((uint32_t*)m_header_table_vaddr)[i] :
((uint64_t*)m_header_table_vaddr)[i];
vaddr_t header_vaddr = map_header(header_paddr);
if (header_vaddr == 0)
continue;
MUST(m_mapped_headers.push_back({
.paddr = header_paddr,
.vaddr = header_vaddr
}));
}
for (size_t i = 0; i < m_mapped_headers.size(); i++)
{
auto* header = m_mapped_headers[i].as_header();
dprintln("found header {}", *header);
if (memcmp(header->signature, "FACP", 4) == 0)
{
auto* fadt = (FADT*)header;
paddr_t dsdt_paddr = 0;
if (fadt->length > offsetof(FADT, x_dsdt))
dsdt_paddr = fadt->x_dsdt;
if (dsdt_paddr == 0 || !PageTable::is_valid_pointer(dsdt_paddr))
dsdt_paddr = fadt->dsdt;
vaddr_t dsdt_vaddr = map_header(dsdt_paddr);
if (dsdt_vaddr == 0)
continue;
MUST(m_mapped_headers.push_back({
.paddr = dsdt_paddr,
.vaddr = dsdt_vaddr
}));
}
}
return {};
}
const ACPI::SDTHeader* ACPI::get_header(BAN::StringView signature, uint32_t index)
{
if (signature.size() != 4)
{
dprintln("Trying to get ACPI header with {} byte signature ??", signature.size());
return nullptr;
}
uint32_t cnt = 0;
for (auto& mapped_header : m_mapped_headers)
{
auto* header = mapped_header.as_header();
if (memcmp(header->signature, signature.data(), 4) == 0)
if (cnt++ == index)
return header;
}
return nullptr;
}
}