Bananymous
b16e65168f
Now AML parsing is actually done while respecting namespaces and scopes. I implemented the minimal functionality to parse qemu's AML. Next step is to implement AML interpreting and then we can drop lai as a dependency.
52 lines
1.1 KiB
C++
52 lines
1.1 KiB
C++
#pragma once
|
|
|
|
#include <BAN/ByteSpan.h>
|
|
#include <BAN/Optional.h>
|
|
|
|
namespace Kernel::ACPI::AML
|
|
{
|
|
|
|
static BAN::Optional<uint32_t> parse_pkg_length(BAN::ConstByteSpan aml_data)
|
|
{
|
|
if (aml_data.size() < 1)
|
|
return {};
|
|
|
|
uint8_t lead_byte = aml_data[0];
|
|
if ((lead_byte & 0xC0) && (lead_byte & 0x30))
|
|
return {};
|
|
|
|
uint32_t pkg_length = lead_byte & 0x3F;
|
|
uint8_t byte_count = (lead_byte >> 6) + 1;
|
|
|
|
if (aml_data.size() < byte_count)
|
|
return {};
|
|
|
|
for (uint8_t i = 1; i < byte_count; i++)
|
|
pkg_length |= aml_data[i] << (i * 8 - 4);
|
|
|
|
return pkg_length;
|
|
}
|
|
|
|
static void trim_pkg_length(BAN::ConstByteSpan& aml_data)
|
|
{
|
|
ASSERT(aml_data.size() >= 1);
|
|
uint8_t byte_count = (aml_data[0] >> 6) + 1;
|
|
aml_data = aml_data.slice(byte_count);
|
|
}
|
|
|
|
static BAN::Optional<BAN::ConstByteSpan> parse_pkg(BAN::ConstByteSpan& aml_data)
|
|
{
|
|
auto pkg_length = parse_pkg_length(aml_data);
|
|
if (!pkg_length.has_value())
|
|
return {};
|
|
|
|
auto result = aml_data.slice(0, pkg_length.value());
|
|
trim_pkg_length(result);
|
|
|
|
aml_data = aml_data.slice(pkg_length.value());
|
|
|
|
return result;
|
|
}
|
|
|
|
}
|