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fix: fix ACPI hardware-ID endianness bug

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daniel
2026-08-15 16:34:57 +02:00
parent c917af0629
commit af7d096969
1 changed files with 15 additions and 0 deletions
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kernel/src/ACPI/AcpiDevices.cpp
+15
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@@ -22,7 +22,22 @@ namespace Hal {
// ============================================================================ // ============================================================================
// ACPI encodes PNP IDs as compressed 32-bit EISAIDs. // ACPI encodes PNP IDs as compressed 32-bit EISAIDs.
static constexpr uint32_t ByteSwap32(uint32_t value) {
return ((value & 0x000000FFu) << 24) |
((value & 0x0000FF00u) << 8) |
((value & 0x00FF0000u) >> 8) |
((value & 0xFF000000u) >> 24);
}
static_assert(ByteSwap32(0x0301D041u) == 0x41D00103u); // PNP0103
static_assert(ByteSwap32(0x090CD041u) == 0x41D00C09u); // PNP0C09
static void DecodeEisaId(uint32_t id, char* out) { static void DecodeEisaId(uint32_t id, char* out) {
// AML exposes the EISAID integer in little-endian byte order, while
// the compressed manufacturer and product fields are defined in
// display order. Convert it before extracting either field.
id = ByteSwap32(id);
// EISA ID encoding: // EISA ID encoding:
// Bits 31-16: 3 compressed letters (5 bits each, '@' based) // Bits 31-16: 3 compressed letters (5 bits each, '@' based)
// Bits 15-0: 4 hex digits (product number) // Bits 15-0: 4 hex digits (product number)