Finished switch to hpet timer

4 files changed, 40 insertions, 47 deletions

diff --git a/kernel/drivers/acpi.c b/kernel/drivers/acpi.c
index 999c0ed..15007d7 100644
--- a/kernel/drivers/acpi.c
+++ b/kernel/drivers/acpi.c
@@ -74,15 +74,18 @@ void acpi_install()
 	hpet = find_sdt(rsdt, HPET_MAGIC);
 }
 
-void hpet_install()
+void hpet_install(int period)
 {
 	if (hpet && hpet->legacy_replacement && hpet->comparator_count > 0) {
 		struct hpet_registers *r = (struct hpet_registers *)hpet->address.phys;
-		printf("HPET tick period: %dns\n", r->features.tick_period / 1000000);
-		printf("Periodic support: %d\n", r->timer.periodic_support);
-		r->config.enable = 1;
-		r->config.legacy_replacement = 1;
-		r->timer.enable = 1;
+		printf("HPET tick period: %dns\n", r->tick_period / 1000000);
+		if ((r->timer0 & hpet_periodic_support) == hpet_periodic_support) {
+			r->config |= hpet_enable;
+			r->config |= hpet_legacy_replacement;
+			r->timer0 |= hpet_periodic | hpet_set_accumulator | hpet_enable_timer;
+			r->timer_comparator0 = r->tick_period + period;
+			r->timer_comparator0 = period;
+		}
 	} else {
 		hpet = NULL;
 	}
diff --git a/kernel/drivers/timer.c b/kernel/drivers/timer.c
index 79e3cd8..788e286 100644
--- a/kernel/drivers/timer.c
+++ b/kernel/drivers/timer.c
@@ -1,5 +1,6 @@
 // MIT License, Copyright (c) 2020 Marvin Borner
 
+#include <acpi.h>
 #include <cpu.h>
 #include <def.h>
 #include <interrupts.h>
@@ -19,7 +20,6 @@ u32 timer_get()
 	return timer_ticks;
 }
 
-// Executed 1000 times per second
 void timer_handler()
 {
 	timer_ticks++;
@@ -39,6 +39,8 @@ void timer_wait(u32 ticks)
 // Install timer handler into IRQ0
 void timer_install()
 {
-	timer_phase(1000);
+	hpet_install(10000); // TODO: Find optimal femtosecond period
+	if (!hpet)
+		timer_phase(1000);
 	irq_install_handler(0, timer_handler);
 }
diff --git a/kernel/inc/acpi.h b/kernel/inc/acpi.h
index 498384e..3a25098 100644
--- a/kernel/inc/acpi.h
+++ b/kernel/inc/acpi.h
@@ -68,48 +68,37 @@ struct hpet {
 	u8 page_protection;
 };
 
+enum hpet_features { hpet_counter_size = 1 << 3, hpet_legacy_replacement_support = 1 << 5 };
+enum hpet_config { hpet_enable = 1 << 0, hpet_legacy_replacement = 1 << 1 };
+enum hpet_timer {
+	hpet_type = 1 << 1,
+	hpet_enable_timer = 1 << 2,
+	hpet_periodic = 1 << 3,
+	hpet_periodic_support = 1 << 4,
+	hpet_size = 1 << 5, // 1 if 64 bit
+	hpet_set_accumulator = 1 << 6,
+	hpet_force_32 = 1 << 8, // For 64 bit
+	hpet_apic_routing = 1 << 13,
+	hpet_fsb = 1 << 14,
+	hpet_fsb_support = 1 << 15,
+	/* routing_capability = 1 << 63 */
+};
+
 struct hpet_registers {
-	struct {
-		u8 revision;
-		u8 comparator_count : 5;
-		u8 counter_size : 1;
-		u8 reserved : 1;
-		u8 legacy_replacement : 1;
-		u16 pci_vendor_id;
-		u32 tick_period;
-	} features;
+	u32 features; // enum hpet_features
+	u32 tick_period;
 	u64 reserved1;
-	struct {
-		u8 enable : 1;
-		u8 legacy_replacement : 1;
-		u64 reserved : 62;
-	} config;
+	u64 config; // enum hpet_config
 	u64 reserved2;
-	struct {
-		u32 status; // For timer #n
-		u32 reserved;
-	} int_status;
-	u8 reserved3[200]; // Why?!
+	u32 int_status; // For timer #n
+	u32 reserved3;
+	u8 reserved4[200]; // Why?!
 	u32 counter;
 	u32 counter_high; // 0 due to 64 bit
-	u64 reserved4;
-	struct {
-		u8 reserved1 : 1;
-		u8 type : 1;
-		u8 enable : 1;
-		u8 periodic : 1;
-		u8 periodic_support : 1;
-		u8 size : 1; // 1 if 64 bit
-		u8 set_accumulator : 1;
-		u8 reserved2 : 1;
-		u8 force_32 : 1; // For 64 bit
-		u8 apic_routing : 5;
-		u8 fsb : 1;
-		u8 fsb_support : 1;
-		u16 reserved3;
-		u32 routing_capability;
-	} timer;
-};
+	u64 reserved5;
+	u64 timer0; // enum hpet_timer
+	u64 timer_comparator0; // In femtoseconds
+} __attribute__((packed));
 
 struct rsdp {
 	struct sdp_header header;
@@ -121,6 +110,6 @@ struct fadt *fadt;
 struct hpet *hpet;
 
 void acpi_install();
-void hpet_install();
+void hpet_install(int period);
 
 #endif
diff --git a/kernel/main.c b/kernel/main.c
index fc304b2..34332e2 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -25,7 +25,6 @@ void kernel_main(struct vid_info *vid_info)
 
 	// Install drivers
 	acpi_install();
-	hpet_install();
 	interrupts_install();
 	fpu_install();
 	timer_install();