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Write hpet timer 0 twice to set accumulator and period

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This allows booting with implementations that require them to be set separately.
Also, check for the availability of legacy-replacement mode and periodic interrupts before using hpet
This commit is contained in:
wartman4404
2018-01-07 16:38:39 -06:00
parent 083c444a68
commit 4f90a0f5c1
2 changed files with 29 additions and 7 deletions
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29
src/arch/x86_64/device/hpet.rs
View File

@@ -11,20 +11,39 @@ static CAPABILITY_OFFSET: usize = 0x00;
static GENERAL_CONFIG_OFFSET: usize = 0x10;
// static GENERAL_INTERRUPT_OFFSET: usize = 0x20;
// static MAIN_COUNTER_OFFSET: usize = 0xF0;
// static NUM_TIMER_CAP_MASK: u64 = 0x0f00;
static LEG_RT_CAP: u64 = 0x8000;
static T0_CONFIG_CAPABILITY_OFFSET: usize = 0x100;
static T0_COMPARATOR_OFFSET: usize = 0x108;
pub unsafe fn init(hpet: &mut Hpet) {
let counter_clk_period_fs = hpet.base_address.read_u64(CAPABILITY_OFFSET) >> 32;
static PER_INT_CAP: u64 = 0x10;
pub unsafe fn init(hpet: &mut Hpet) -> bool {
let capability = hpet.base_address.read_u64(CAPABILITY_OFFSET);
if capability & LEG_RT_CAP == 0 {
return false;
}
let counter_clk_period_fs = capability >> 32;
let desired_fs_period: u64 = 2_250_286 * 1_000_000;
let clk_periods_per_kernel_tick: u64 = desired_fs_period / counter_clk_period_fs;
let t0_capabilities = hpet.base_address.read_u64(T0_CONFIG_CAPABILITY_OFFSET);
if t0_capabilities & PER_INT_CAP == 0 {
return false;
}
let t0_config_word: u64 = TN_VAL_SET_CNF | TN_TYPE_CNF | TN_INT_ENB_CNF;
hpet.base_address.write_u64(T0_CONFIG_CAPABILITY_OFFSET, t0_config_word);
hpet.base_address.write_u64(T0_COMPARATOR_OFFSET, clk_periods_per_kernel_tick);
// set accumulator value
hpet.base_address.write_u64(T0_COMPARATOR_OFFSET, clk_periods_per_kernel_tick);
// set interval
let enable_word: u64 = hpet.base_address.read_u64(GENERAL_CONFIG_OFFSET) | LEG_RT_CNF | ENABLE_CNF;
hpet.base_address.write_u64(GENERAL_CONFIG_OFFSET, enable_word);
// Enable interrupts from the HPET
let t0_config_word: u64 = TN_VAL_SET_CNF | TN_TYPE_CNF | TN_INT_ENB_CNF;
hpet.base_address.write_u64(T0_CONFIG_CAPABILITY_OFFSET, t0_config_word);
hpet.base_address.write_u64(T0_COMPARATOR_OFFSET, clk_periods_per_kernel_tick);
true
}

7
src/arch/x86_64/device/mod.rs
View File

@@ -16,9 +16,12 @@ pub unsafe fn init(active_table: &mut ActivePageTable){
pub unsafe fn init_noncore() {
{
if let Some(ref mut hpet) = *ACPI_TABLE.hpet.write() {
hpet::init(hpet);
let using_hpet = if let Some(ref mut hpet) = *ACPI_TABLE.hpet.write() {
hpet::init(hpet)
} else {
false
};
if !using_hpet {
pit::init();
}
}