feat(os): refine kernel memory management, ACPI power state logic, and window manager rendering pipeline

Author: skyyii

include/drivers/acpi/acpi.h

@@ -1,87 +1,114 @@
-#pragma once
-#include <stdint.h>
-
-// ACPI RSDP (Root System Description Pointer) structures
-struct AcpiRsdp
-{
-    char signature[8]; // "RSD PTR "
-    uint8_t checksum;
-    char oem_id[6];
-    uint8_t revision;      // 0 = ACPI 1.0, 2 = ACPI 2.0+
-    uint32_t rsdt_address; // Physical address of RSDT
-} __attribute__((packed));
-
-struct AcpiRsdp20
-{
-    AcpiRsdp base;
-    uint32_t length;
-    uint64_t xsdt_address; // Physical address of XSDT (64-bit)
-    uint8_t extended_checksum;
-    uint8_t reserved[3];
-} __attribute__((packed));
-
-// ACPI SDT Header (common to all tables)
-struct AcpiSdtHeader
-{
-    char signature[4];
-    uint32_t length;
-    uint8_t revision;
-    uint8_t checksum;
-    char oem_id[6];
-    char oem_table_id[8];
-    uint32_t oem_revision;
-    uint32_t creator_id;
-    uint32_t creator_revision;
-} __attribute__((packed));
-
-// ACPI FADT (Fixed ACPI Description Table) - partial, we only need power management fields
-struct AcpiFadt
-{
-    AcpiSdtHeader header;
-    uint32_t firmware_ctrl;
-    uint32_t dsdt;
-    uint8_t reserved1;
-    uint8_t preferred_pm_profile;
-    uint16_t sci_int;
-    uint32_t smi_cmd;
-    uint8_t acpi_enable;
-    uint8_t acpi_disable;
+#pragma once
+#include <stdint.h>
+
+// ACPI RSDP (Root System Description Pointer) structures
+struct AcpiRsdp
+{
+    char signature[8]; // "RSD PTR "
+    uint8_t checksum;
+    char oem_id[6];
+    uint8_t revision;      // 0 = ACPI 1.0, 2 = ACPI 2.0+
+    uint32_t rsdt_address; // Physical address of RSDT
+} __attribute__((packed));
+
+struct AcpiRsdp20
+{
+    AcpiRsdp base;
+    uint32_t length;
+    uint64_t xsdt_address; // Physical address of XSDT (64-bit)
+    uint8_t extended_checksum;
+    uint8_t reserved[3];
+} __attribute__((packed));
+
+// ACPI SDT Header (common to all tables)
+struct AcpiSdtHeader
+{
+    char signature[4];
+    uint32_t length;
+    uint8_t revision;
+    uint8_t checksum;
+    char oem_id[6];
+    char oem_table_id[8];
+    uint32_t oem_revision;
+    uint32_t creator_id;
+    uint32_t creator_revision;
+} __attribute__((packed));
+
+struct AcpiGas
+{
+    uint8_t address_space;
+    uint8_t bit_width;
+    uint8_t bit_offset;
+    uint8_t access_size;
+    uint64_t address;
+} __attribute__((packed));
+
+// ACPI FADT (Fixed ACPI Description Table)
+struct AcpiFadt
+{
+    AcpiSdtHeader header;
+    uint32_t firmware_ctrl;
+    uint32_t dsdt;
+    uint8_t reserved1;
+    uint8_t preferred_pm_profile;
+    uint16_t sci_int;
+    uint32_t smi_cmd;
+    uint8_t acpi_enable;
+    uint8_t acpi_disable;
     uint8_t s4_firmware_req;
-    uint8_t pstate_cnt;
-    uint32_t pm1a_evt_blk;
-    uint32_t pm1b_evt_blk;
-    uint32_t pm1a_cnt_blk; // PM1a Control Block (we need this for shutdown)
-    uint32_t pm1b_cnt_blk; // PM1b Control Block (optional)
-    uint32_t pm2_cnt_blk;
-    uint32_t pm_tmr_blk;
-    uint32_t gpe0_blk;
-    uint32_t gpe1_blk;
-    uint8_t pm1_evt_len;
-    uint8_t pm1_cnt_len;
-    uint8_t pm2_cnt_len;
-    uint8_t pm_tmr_len;
-    // ... more fields we don't need
-} __attribute__((packed));
-
-// ACPI MCFG structure (PCI PCIe MMIO Configuration)
-struct AcpiMcfgEntry
-{
-    uint64_t base_address;
-    uint16_t pci_segment;
-    uint8_t start_bus;
-    uint8_t end_bus;
-    uint32_t reserved;
-} __attribute__((packed));
-
-struct AcpiMcfg
-{
-    AcpiSdtHeader header;
-    uint64_t reserved;
+    uint8_t pstate_cnt;
+    uint32_t pm1a_evt_blk;
+    uint32_t pm1b_evt_blk;
+    uint32_t pm1a_cnt_blk;
+    uint32_t pm1b_cnt_blk;
+    uint32_t pm2_cnt_blk;
+    uint32_t pm_tmr_blk;
+    uint32_t gpe0_blk;
+    uint32_t gpe1_blk;
+    uint8_t pm1_evt_len;
+    uint8_t pm1_cnt_len;
+    uint8_t pm2_cnt_len;
+    uint8_t pm_tmr_len;
+    uint8_t gpe0_blk_len;
+    uint8_t gpe1_blk_len;
+    uint8_t gpe1_base;
+    uint8_t cstate_cnt;
+    uint16_t lvl2_lat;
+    uint16_t lvl3_lat;
+    uint16_t flush_size;
+    uint16_t flush_stride;
+    uint8_t duty_offset;
+    uint8_t duty_width;
+    uint8_t day_alrm;
+    uint8_t mon_alrm;
+    uint8_t century;
+    uint16_t iapc_boot_arch;
+    uint8_t reserved2;
+    uint32_t flags;
+    AcpiGas reset_reg;
+    uint8_t reset_value;
+} __attribute__((packed));
+
+// ACPI MCFG structure (PCI PCIe MMIO Configuration)
+struct AcpiMcfgEntry
+{
+    uint64_t base_address;
+    uint16_t pci_segment;
+    uint8_t start_bus;
+    uint8_t end_bus;
+    uint32_t reserved;
+} __attribute__((packed));
+
+struct AcpiMcfg
+{
+    AcpiSdtHeader header;
+    uint64_t reserved;
     AcpiMcfgEntry entries[1];
-} __attribute__((packed));
-
-// ACPI functions
-void acpi_init();
-void *acpi_find_table(const char *signature);
-bool acpi_poweroff();
-bool acpi_is_available();
+} __attribute__((packed));
+
+// ACPI functions
+void acpi_init();
+void *acpi_find_table(const char *signature);
+bool acpi_reboot();
+bool acpi_poweroff();
+bool acpi_is_available();

include/uapi/gui.h

@@ -68,6 +68,7 @@ typedef struct WindowEntry
 {
     volatile int shm_id;
     volatile int x, y, w, h;
+    volatile uint32_t position_serial;
     volatile int restore_x, restore_y, restore_w, restore_h;
     volatile int buffer_w, buffer_h;
     volatile int content_w, content_h;

include/uapi/syscalls.h

@@ -81,6 +81,7 @@
 #define SYS_DISPLAY_ATOMIC_COMMIT 260
 #define SYS_DISPLAY_BUFFER_SET_WM_ACCESS 261
 #define SYS_DISPLAY_SURFACE_IMPORT 262
+#define SYS_SHM_GET_OWNER 263
 
 #define SYS_SIGACTION 13
 #define SYS_SIGRETURN 15

src/drivers/acpi/acpi.cpp

@@ -14,8 +14,11 @@ static uint16_t slp_typa = 0;       // Sleep type value for S5
 static uint16_t slp_typb = 0;       // Sleep type value for S5 (optional)
 static uint32_t smi_cmd_port = 0;   // SMI command port
 static uint8_t acpi_enable_val = 0; // Value to write to enable ACPI
+static AcpiGas g_reset_reg = {};    // ACPI Reset Register
+static uint8_t g_reset_value = 0;   // ACPI Reset Value
 static bool g_rsdp_logged = false;
 
+
 // Sleep enable bit
 #define ACPI_SLP_EN (1 << 13)
 
@@ -269,14 +272,16 @@ void acpi_init()
             pm1b_cnt = fadt->pm1b_cnt_blk;
             smi_cmd_port = fadt->smi_cmd;
             acpi_enable_val = fadt->acpi_enable;
+            g_reset_reg = fadt->reset_reg;
+            g_reset_value = fadt->reset_value;
 
             // Parse DSDT to find S5 sleep type
             if (fadt->dsdt) {
                 find_s5_in_dsdt(fadt->dsdt);
             }
 
             acpi_available = true;
-            DEBUG_SUCCESS("ACPI ready (PM1a=0x%x)", pm1a_cnt);
+            DEBUG_SUCCESS("ACPI ready (PM1a=0x%x, Reset=0x%lx)", pm1a_cnt, g_reset_reg.address);
             return;
         }
     }
@@ -292,6 +297,30 @@ bool acpi_is_available()
 // SCI_EN bit in PM1_CNT register
 #define ACPI_SCI_EN (1 << 0)
 
+bool acpi_reboot()
+{
+    if (!acpi_available || g_reset_reg.address == 0)
+        return false;
+
+    DEBUG_INFO("acpi: attempting hardware reset via 0x%lx...", g_reset_reg.address);
+    asm volatile("cli");
+
+    if (g_reset_reg.address_space == 1) { // System I/O
+        outb((uint16_t)g_reset_reg.address, g_reset_value);
+    } else if (g_reset_reg.address_space == 0) { // System Memory
+        // We'd need to map this if it's not in HHDM or already mapped
+        // For simplicity, we assume HHDM or identity for now if low enough
+        if (g_reset_reg.address < 0x100000000ULL) {
+            uint8_t *ptr = reinterpret_cast<uint8_t *>(vmm_phys_to_virt(g_reset_reg.address));
+            *ptr = g_reset_value;
+        }
+    }
+
+    for (volatile int i = 0; i < 1000000; i++)
+        ;
+    return false;
+}
+
 bool acpi_poweroff()
 {
     DEBUG_INFO("acpi: starting shutdown sequence...");

src/drivers/video/display.cpp

@@ -2915,8 +2915,8 @@ bool display_event_wait(DisplayEvent *out_event, bool block)
     if (!out_event)
         return false;
 
+    spinlock_acquire(&s_display_event_lock);
     for (;;) {
-        spinlock_acquire(&s_display_event_lock);
         if (display_pop_event_locked(out_event)) {
             spinlock_release(&s_display_event_lock);
             return true;
@@ -2926,9 +2926,9 @@ bool display_event_wait(DisplayEvent *out_event, bool block)
             return false;
         }
 
+        // scheduler_wait atomically drops the lock and sleeps.
+        // It returns with the lock re-acquired.
         scheduler_wait(&s_display_event_wait_queue, &s_display_event_lock);
-        // scheduler_wait re-acquires the lock on wake, but display_event_wait 
-        // doesn't need to release it again here since the loop will handle it.
     }
 }
 

src/kernel/core/syscall.cpp

@@ -542,7 +542,7 @@ extern "C" void signal_check(SyscallFrame *frame)
 
 [[nodiscard]] static uint64_t sys_kill(uint64_t pid, int sig)
 {
-    if (sig <= 0 || sig > 31)
+    if (sig < 0 || sig > 31)
         return static_cast<uint64_t>(-1);
 
     Process *current = process_get_current();
@@ -554,7 +554,9 @@ extern "C" void signal_check(SyscallFrame *frame)
         return static_cast<uint64_t>(-1);
     }
 
-    signal_send(target, sig);
+    if (sig != 0) {
+        signal_send(target, sig);
+    }
     return 0;
 }
 
@@ -2113,6 +2115,15 @@ extern "C" uint64_t syscall_handler(uint64_t syscall_num, uint64_t arg1, uint64_
             spinlock_release(&g_shm_lock);
             return size;
         }
+        case SYS_SHM_GET_OWNER: {
+            int id = (int)arg1;
+            if (id < 0 || id >= 64)
+                return static_cast<uint64_t>(-1);
+            spinlock_acquire(&g_shm_lock);
+            uint32_t owner = g_shm_blocks[id].used ? g_shm_blocks[id].owner_pid : 0;
+            spinlock_release(&g_shm_lock);
+            return (uint64_t)owner;
+        }
         case SYS_SHM_UNMAP:
             return shm_unmap_from_process(process_get_current(), (int)arg1) ? 0 : static_cast<uint64_t>(-1);
         default:

src/kernel/sched/scheduler.cpp

@@ -506,6 +506,10 @@ void system_reboot()
 {
     shutdown_prepare(1, "System rebooting...");
 
+    asm volatile("wbinvd" ::: "memory");
+    asm volatile("cli" ::: "memory");
+
+    acpi_reboot();
     reboot_via_keyboard_controller();
     reboot_via_pci_reset_control();
     reboot_via_triple_fault();
@@ -516,6 +520,9 @@ void system_poweroff()
 {
     shutdown_prepare(2, "System powering off...");
 
+    asm volatile("wbinvd" ::: "memory");
+    asm volatile("cli" ::: "memory");
+
     acpi_poweroff();
     DEBUG_WARN("Poweroff failed, halting CPU.");
     halt_forever();