Use __packed in guid.h

arch/x86_64/acpi.c

@@ -0,0 +1,36 @@
+#include <stdckdint.h>
+#include <stdint.h>
+#include <uacpi/kernel_api.h>
+#include <uacpi/status.h>
+#include <x86_64/asm.h>
+
+uacpi_status uacpi_kernel_io_map(uacpi_io_addr base, uacpi_size len, uacpi_handle* out_handle) {
+    uintptr_t end;
+    if (ckd_add(&end, base, len) || end > 0x10000)
+        return UACPI_STATUS_INVALID_ARGUMENT;
+    *out_handle = (uacpi_handle)(uintptr_t)base;
+    return UACPI_STATUS_OK;
+}
+
+void uacpi_kernel_io_unmap(uacpi_handle handle) {
+    // Left intentionally blank.
+}
+
+#define IO_READ(width, suffix) \
+    uacpi_status uacpi_kernel_io_read##width(uacpi_handle handle, uacpi_size offset, uacpi_u##width* out_value) { \
+        *out_value = asm_in##suffix((uintptr_t)handle + offset); \
+        return UACPI_STATUS_OK; \
+    }
+
+#define IO_WRITE(width, suffix) \
+    uacpi_status uacpi_kernel_io_write##width(uacpi_handle handle, uacpi_size offset, uacpi_u##width in_value) { \
+        asm_out##suffix((uintptr_t)handle + offset, in_value); \
+        return UACPI_STATUS_OK; \
+    }
+
+IO_READ(8, b)
+IO_READ(16, w)
+IO_READ(32, l)
+IO_WRITE(8, b)
+IO_WRITE(16, w)
+IO_WRITE(32, l)

arch/x86_64/apic.c

@@ -7,6 +7,7 @@
 #include <zinnia/utils.h>
 #include <zinnia/vma.h>
 #include <arch/cpu.h>
+#include <arch/timer.h>
 #include <stdint.h>
 #include <x86_64/apic.h>
 #include <x86_64/asm.h>
@@ -95,17 +96,22 @@ void lapic_init(struct local_apic* lapic) {
     clock_spin_ns(10'000'000);
 
     lapic->ticks_per_10ms = 0xFFFF'FFFF - lapic_read_reg(lapic, APIC_REG_CCR);
-    lapic_write_reg(lapic, APIC_REG_LVT_TR, IDT_IPI_RESCHED | 0x20000);
-    lapic_write_reg(lapic, APIC_REG_ICR_TIMER, lapic->ticks_per_10ms);
+    lapic_write_reg(lapic, APIC_REG_LVT_TR, mmio_field(APIC_LVT_TR_VECTOR, IDT_TIMER));
+    lapic_write_reg(lapic, APIC_REG_ICR_TIMER, 0);
+}
+
+void arch_timer_program(uint64_t deadline_ns) {
+    struct local_apic* lapic = &percpu_ref(arch_data)->lapic;
+    const uint64_t now = clock_get_elapsed_ns();
+    const uint64_t delta = MIN(deadline_ns > now ? deadline_ns - now : 0, 1'000'000'000);
+    const uint64_t ticks = delta * lapic->ticks_per_10ms / 10'000'000;
+    lapic_write_reg(lapic, APIC_REG_ICR_TIMER, MIN(MAX(ticks, 1), 0xFFFF'FFFF));
 }
 
 void lapic_eoi(struct local_apic* lapic) {
     lapic_write_reg(lapic, APIC_REG_EOI, 0);
 }
 
-constexpr uint64_t the_icr =
-    mmio_field(APIC_ICR_VECTOR, 128) | mmio_field(APIC_ICR_DELIVERY_MODE, APIC_DELIVERY_STARTUP);
-
 void lapic_send_ipi(
     struct local_apic* lapic,
     uint32_t target,

arch/x86_64/meson.build

@@ -27,3 +27,7 @@ kernel_sources += files(
 if kconfig.get('CONFIG_PCI', 'n') == 'y'
     kernel_sources += files('pci.c')
 endif
+
+if kconfig.get('CONFIG_ACPI', 'n') == 'y'
+    kernel_sources += files('acpi.c')
+endif

include/arch/timer.h

@@ -0,0 +1,5 @@
+#pragma once
+
+#include <stdint.h>
+
+void arch_timer_program(uint64_t deadline_ns);

include/zinnia/guid.h

@@ -1,9 +1,10 @@
 #pragma once
 
+#include <zinnia/compiler.h>
 #include <stddef.h>
 #include <stdint.h>
 
-struct [[gnu::packed]] guid {
+struct [[__packed]] guid {
     uint32_t time_low;
     uint16_t time_mid;
     uint16_t time_hi_version;