Add FADT struct

Ratakor · Oct 9, 2023 · de4d685 · de4d685
1 parent ae9a911
commit de4d685
Showing 1 changed file with 87 additions and 11 deletions.
diff --git a/kernel/acpi.zig b/kernel/acpi.zig
@@ -17,10 +17,21 @@ const SDT = extern struct {
     creator_id: u32 align(1),
     creator_revision: u32 align(1),
 
-    pub inline fn data(self: *const @This()) []const u8 {
-        const ptr: [*]const u8 = @ptrCast(@alignCast(self));
+    inline fn data(self: *const SDT) []const u8 {
+        const ptr: [*]const u8 = @ptrCast(self);
         return ptr[0..self.length][@sizeOf(SDT)..];
     }
+
+    fn validChecksum(self: *const SDT) void {
+        const ptr: [*]const u8 = @ptrCast(self);
+        var sum: u8 = 0;
+        for (0..self.length) |i| {
+            sum +%= ptr[i];
+        }
+        if (sum != 0) {
+            std.debug.panic("SDT `{s}` is invalid: sum = {}", .{ self.signature, sum });
+        }
+    }
 };
 
 /// Root System Description Pointer
@@ -41,6 +52,73 @@ const RSDP = extern struct {
     }
 };
 
+/// Generic Address Structure
+const GAS = extern struct {
+    address_space: u8 align(1),
+    bit_width: u8 align(1),
+    bit_offset: u8 align(1),
+    access_size: u8 align(1),
+    address: u64 align(1),
+};
+
+/// Fixed ACPI Description Table
+const FADT = extern struct {
+    header: SDT align(1),
+    firmware_ctrl: u32 align(1),
+    dsdt: u32 align(1),
+    reserved1: u8 align(1), // ACPI 1 only
+    preferred_power_management_profile: u8 align(1),
+    sci_interrupt: u16 align(1),
+    smi_command_port: u32 align(1),
+    acpi_enable: u8 align(1),
+    acpi_disable: u8 align(1),
+    s4bios_req: u8 align(1),
+    pstate_control: u8 align(1),
+    pm1a_event_block: u32 align(1),
+    pm1b_event_block: u32 align(1),
+    pm1a_control_block: u32 align(1),
+    pm1b_control_block: u32 align(1),
+    pm2_control_block: u32 align(1),
+    pm_timer_block: u32 align(1),
+    gpe0_block: u32 align(1),
+    gpe1_block: u32 align(1),
+    pm1_event_length: u8 align(1),
+    pm1_control_length: u8 align(1),
+    pm2_control_length: u8 align(1),
+    pm_timer_length: u8 align(1),
+    gpe0_length: u8 align(1),
+    gpe1_length: u8 align(1),
+    gpe1_base: u8 align(1),
+    c_state_control: u8 align(1),
+    worst_c2_latency: u16 align(1),
+    worst_c3_latency: u16 align(1),
+    flush_size: u16 align(1),
+    flush_stride: u16 align(1),
+    duty_offset: u8 align(1),
+    duty_width: u8 align(1),
+    day_alarm: u8 align(1),
+    month_alarm: u8 align(1),
+    century: u8 align(1),
+    boot_architecture_flags: u16 align(1), // ACPI 2 only
+    reserved2: u8 align(1),
+    flags: u32 align(1),
+    reset_reg: GAS align(1),
+    reset_value: u8 align(1),
+    reserved3: [3]u8 align(1),
+    x_firmware_control: u64 align(1), // ACPI 2 only
+    x_dsdt: u64 align(1), // ACPI 2 only
+    x_pm1a_event_block: GAS align(1),
+    x_pm1b_event_block: GAS align(1),
+    x_pm1a_control_block: GAS align(1),
+    x_pm1b_control_block: GAS align(1),
+    x_pm2_control_block: GAS align(1),
+    x_pm_timer_block: GAS align(1),
+    x_gpe0_block: GAS align(1),
+    x_gpe1_block: GAS align(1),
+};
+
+var fadt: *const FADT = undefined;
+
 pub fn init() void {
     const rsdp: *RSDP = @ptrCast(@alignCast(root.rsdp_request.response.?.address));
 
@@ -56,23 +134,17 @@ pub fn init() void {
 
 fn parse(comptime T: type, addr: u64) void {
     const rsdt: *const SDT = @ptrFromInt(addr + vmm.hhdm_offset);
-
-    var sum: u8 = 0;
-    for (0..rsdt.length) |i| {
-        sum +%= @as([*]const u8, @ptrCast(rsdt))[i];
-    }
-    if (sum != 0) {
-        std.debug.panic("RSDT is invalid: sum = {}", .{sum});
-    }
-
+    rsdt.validChecksum();
     log.info("RSDT is at 0x{x}", .{@intFromPtr(rsdt)});
 
     const entries = std.mem.bytesAsSlice(T, rsdt.data());
     for (entries) |entry| {
         const sdt: *const SDT = @ptrFromInt(entry + vmm.hhdm_offset);
+        sdt.validChecksum();
 
         switch (readIntNative(u32, &sdt.signature)) {
             readIntNative(u32, "APIC") => handleMADT(sdt),
+            readIntNative(u32, "FACP") => handleFADT(sdt),
             else => log.warn("unhandled ACPI table: {s}", .{sdt.signature}),
         }
     }
@@ -102,3 +174,7 @@ fn handleMADT(madt: *const SDT) void {
         data = data[@max(2, size)..];
     }
 }
+
+fn handleFADT(sdt: *const SDT) void {
+    fadt = @ptrCast(sdt);
+}