diff --git a/driver/acpi.c b/driver/acpi.c
deleted file mode 100644
index 4d2202a..0000000
--- a/driver/acpi.c
+++ /dev/null
@@ -1,146 +0,0 @@
-#include "../include/acpi.h"
-#include "../include/graphics.h"
-#include "../include/memory.h"
-#include "../include/io.h"
-#include "../include/timer.h"
-
-struct FADT *fadt;
-struct DSDT_vals dsdt;
-void *dsdt_ptr;
-
-void *findRSDP() {
-    printf("ACPI: searching RSDP");
-    uint8_t * mem = (uint8_t * )
-    0x000E0000;
-    while ((unsigned int) mem != 0x000FFFFF) {
-        if (memcmp(mem, "RSD PTR ", 8) == 0) {
-            uint8_t * bptr = (uint8_t * )
-            mem;
-            uint8_t check = 0;
-            for (unsigned int i = 0; i < sizeof(struct RSDPDescriptor); i++) {
-                check += *bptr;
-                bptr++;
-            }
-            if (((struct RSDPDescriptor *) mem)->Revision >= 1) {
-                check = 0;
-                uint8_t * bptr20 = (uint8_t * )
-                mem;
-                for (unsigned int j = 0; j < sizeof(struct RSDPDescriptor20); j++) {
-                    check += *bptr20;
-                    bptr20++;
-                }
-            }
-            if (!check) {
-                printf("Done, RSDP found on 0x%08x", mem);
-                return mem;
-            } else {
-                printf("error: ACPI RSDP checksum is invalid.");
-            }
-        }
-        mem++;
-    }
-    printf("RSDP not found.");
-    return 0;
-}
-
-int acpi_check_hdr(uint8_t *table, const char *sig, int n) {
-    if (memcmp(table, sig, n) != 0)
-        return 1;
-    uint8_t checksum = 0;
-    if (checksum == 0)
-        return 0;
-    return 1;
-}
-
-void parse_dsdt() {
-    if (fadt == 0) {
-        printf("ACPI: FADT not found!");
-    }
-    if (acpi_check_hdr((uint8_t * )(int)fadt->Dsdt, "DSDT", 4)!=0){
-        printf("ACPI: Invalid DSDT signature!");
-    }
-    dsdt_ptr = (void *) fadt->Dsdt;
-    dsdt.length = ((struct ACPISDTHeader *) dsdt_ptr)->Length - sizeof(struct ACPISDTHeader);
-    int i;
-    for (i = 0; i <= dsdt.length; i++) {
-        if (memcmp(dsdt_ptr + sizeof(struct ACPISDTHeader) + i, "_S5_", 4) == 0) {
-            dsdt.S5_object = dsdt_ptr + i;
-            break;
-        }
-    }
-    if (i == dsdt.length) {
-        printf("ACPI: No S5 object in DSDT.");
-    }
-}
-
-void parse_acpi(void *mem) {
-    struct RSDPDescriptor *rsdp = mem;
-    struct RSDT *rsdt = (struct RSDT *) (rsdp->RsdtAddress);
-    int i = 0;
-    if (acpi_check_hdr((uint8_t * )(int)rsdt, "RSDT", 4)!=0)
-    {
-        printf("ACPI: Invalid RSDT signature.");
-    }
-    while (acpi_check_hdr((uint8_t * )(&rsdt->PointerToOtherSDT)[i], "FACP", 4) != 0 && i <= 64)
-        i++;
-    if (i < 64) {
-        fadt = (struct FADT *) (&rsdt->PointerToOtherSDT)[i];
-    } else {
-        printf("ACPI: FADT not found!");
-    }
-    const char *pm_profile_strings[9] = {"unspecified", "desktop", "notebook", "mobile", "workstation",
-                                         "enterprice server", "SOHO server", "appliance PC", "perfomance server"};
-    printf("This PC's power management profile is %s",
-           (fadt->PreferredPowerManagementProfile < 8) ? pm_profile_strings[fadt->PreferredPowerManagementProfile]
-                                                       : "unknown, field is in reserved value");
-    //Then parse the DSDT and enable ACPI.
-    parse_dsdt();
-    acpi_enable();
-}
-
-void parse_acpi20(void *mem) {
-    struct RSDPDescriptor20 *rsdp = (struct RSDPDescriptor20 *) mem;
-    struct XSDT *xsdt = (struct XSDT *) (int) (rsdp->XsdtAddress);
-    int i = 0;
-    while (acpi_check_hdr((uint8_t * )(int)(&xsdt->PointerToOtherSDT)[i], "FACP", 4)!=0 && i <= 64)
-    i++;
-    if (i < 64) {
-        fadt = (struct FADT *) (int) (&xsdt->PointerToOtherSDT)[i];
-    } else {
-        printf("ACPI: FADT not found!");
-    }
-    parse_dsdt();
-    acpi_enable();
-}
-
-void acpi_enable() {
-    printf("ACPI: Trying to enable ACPI...");
-    if ((inw(fadt->PM1aControlBlock) >> 1 & 1) == 0) {
-        printf("ACPI already enabled");
-        return;
-    }
-    outb(fadt->SMI_CommandPort, fadt->AcpiEnable);
-    int i;
-    for (i = 0; i < 300; i++) {
-        if ((inw(fadt->PM1aControlBlock) & 1) == 0)
-            break;
-        clock_sleep(4);
-    }
-    if ((inw(fadt->PM1aControlBlock) & 1) != 0) {
-        printf("Failed to enable ACPI.");
-    }
-    printf("ACPI: ACPI enabled!");
-}
-
-void init_acpi() {
-    struct RSDPDescriptor *rsdp = findRSDP();
-    if (rsdp == NULL) {
-        printf("\nNo ACPI on this computer.");
-    }
-    if (rsdp->Revision >= 1) {
-        parse_acpi20((void *) rsdp);
-        return;
-    }
-    parse_acpi((void *) rsdp);
-}
-
diff --git a/include/acpi.h b/include/acpi.h
deleted file mode 100644
index c272863..0000000
--- a/include/acpi.h
+++ /dev/null
@@ -1,132 +0,0 @@
-#ifndef CRASHPOWEROS_ACPI_H
-#define CRASHPOWEROS_ACPI_H
-
-#include <stdint.h>
-
-typedef struct RSDPDescriptor RSDPDescriptor;
-typedef struct GenericAddressStructure GenericAddressStructure;
-
-struct RSDPDescriptor {
-    char Signature[8];
-    uint8_t Checksum;
-    char OEMID[6];
-    uint8_t Revision;
-    uint32_t RsdtAddress;
-} __attribute__ ((packed));
-
-struct RSDPDescriptor20 {
-    struct RSDPDescriptor firstPart;
-
-    uint32_t Length;
-    uint64_t XsdtAddress;
-    uint8_t ExtendedChecksum;
-    uint8_t reserved[3];
-} __attribute__ ((packed));
-
-struct ACPISDTHeader {
-    char Signature[4];
-    uint32_t Length;
-    uint8_t Revision;
-    uint8_t Checksum;
-    char OEMID[6];
-    char OEMTableID[8];
-    uint32_t OEMRevision;
-    uint32_t CreatorID;
-    uint32_t CreatorRevision;
-};
-
-struct RSDT {
-    struct ACPISDTHeader h;
-    uint32_t PointerToOtherSDT;
-};
-
-struct XSDT {
-    struct ACPISDTHeader h;
-    uint64_t PointerToOtherSDT;
-};
-
-struct GenericAddressStructure {
-    uint8_t AddressSpace;
-    uint8_t BitWidth;
-    uint8_t BitOffset;
-    uint8_t AccessSize;
-    uint64_t Address;
-};
-
-struct FADT {
-    struct ACPISDTHeader h;
-    uint32_t FirmwareCtrl;
-    uint32_t Dsdt;
-
-    uint8_t Reserved;
-
-    uint8_t PreferredPowerManagementProfile;
-    uint16_t SCI_Interrupt;
-    uint32_t SMI_CommandPort;
-    uint8_t AcpiEnable;
-    uint8_t AcpiDisable;
-    uint8_t S4BIOS_REQ;
-    uint8_t PSTATE_Control;
-    uint32_t PM1aEventBlock;
-    uint32_t PM1bEventBlock;
-    uint32_t PM1aControlBlock;
-    uint32_t PM1bControlBlock;
-    uint32_t PM2ControlBlock;
-    uint32_t PMTimerBlock;
-    uint32_t GPE0Block;
-    uint32_t GPE1Block;
-    uint8_t PM1EventLength;
-    uint8_t PM1ControlLength;
-    uint8_t PM2ControlLength;
-    uint8_t PMTimerLength;
-    uint8_t GPE0Length;
-    uint8_t GPE1Length;
-    uint8_t GPE1Base;
-    uint8_t CStateControl;
-    uint16_t WorstC2Latency;
-    uint16_t WorstC3Latency;
-    uint16_t FlushSize;
-    uint16_t FlushStride;
-    uint8_t DutyOffset;
-    uint8_t DutyWidth;
-    uint8_t DayAlarm;
-    uint8_t MonthAlarm;
-    uint8_t Century;
-
-    uint16_t BootArchitectureFlags;
-
-    uint8_t Reserved2;
-    uint32_t Flags;
-
-    GenericAddressStructure ResetReg;
-
-    uint8_t ResetValue;
-    uint8_t Reserved3[3];
-
-    uint64_t X_FirmwareControl;
-    uint64_t X_Dsdt;
-
-    GenericAddressStructure X_PM1aEventBlock;
-    GenericAddressStructure X_PM1bEventBlock;
-    GenericAddressStructure X_PM1aControlBlock;
-    GenericAddressStructure X_PM1bControlBlock;
-    GenericAddressStructure X_PM2ControlBlock;
-    GenericAddressStructure X_PMTimerBlock;
-    GenericAddressStructure X_GPE0Block;
-    GenericAddressStructure X_GPE1Block;
-};
-
-struct DSDT_vals {
-    int length;
-    void *S5_object;
-};
-
-void *findRSDP();
-int acpi_check_hdr(uint8_t *table, const char *sig, int n);
-void parse_dsdt();
-void parse_acpi(void *mem);
-void parse_acpi20(void *mem);
-void acpi_enable();
-void init_acpi();
-
-#endif //CRASHPOWEROS_ACPI_H
diff --git a/include/common.h b/include/common.h
index 97efb3f..9f9fe35 100644
--- a/include/common.h
+++ b/include/common.h
@@ -2,7 +2,10 @@
 #define CRASHPOWEROS_COMMON_H
 
 #define OS_NAME "CrashPowerDOS"
-#define OS_VERSION "v0.2.2"
+#define OS_VERSION "v0.2.3"
+
+#define LONG_MAX 9223372036854775807L
+#define LONG_MIN -9223372036854775808L
 
 #include <stddef.h>
 #include <stdint.h>
@@ -27,5 +30,6 @@ char *uint32_to_str_oct(uint32_t num, int flag, int width);
 char *insert_str(char *buf, const char *str);
 int vsprintf(char *buf, const char *fmt, va_list args);
 int sprintf(char *buf, const char *fmt, ...);
+long int strtol(const char *str,char **endptr,int base);
 
 #endif //CRASHPOWEROS_COMMON_H
diff --git a/include/shell.h b/include/shell.h
index 2e52337..f6b66b5 100644
--- a/include/shell.h
+++ b/include/shell.h
@@ -10,7 +10,7 @@ void setup_shell();
 
 //内置命令
 void cmd_echo(int argc,char **argv);
-void cmd_proc();
+void cmd_proc(int argc, char **argv);
 void cmd_date();
 void cmd_reset();
 void cmd_del(int argc, char **argv);
diff --git a/include/task.h b/include/task.h
index 97c4ebf..0c88ff8 100644
--- a/include/task.h
+++ b/include/task.h
@@ -44,4 +44,6 @@ void schedule();
 
 void change_task_to(struct task_struct *next);
 
+void task_kill(int pid);
+
 #endif //CRASHPOWEROS_TASK_H
diff --git a/kernel/kernel.c b/kernel/kernel.c
index 3f02cab..72b9d07 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -10,7 +10,6 @@
 #include "../include/keyboard.h"
 #include "../include/shell.h"
 #include "../include/date.h"
-#include "../include/acpi.h"
 
 extern uint32_t end;
 extern int status;
@@ -37,7 +36,6 @@ void kernel_main(multiboot_t *multiboot) {
     printf("[\035kernel\036]: PCB load success!\n");
     init_keyboard();
     printf("[\035kernel\036]: Keyboard driver load success!\n");
-    //init_acpi();printf("[\035kernel\036]: ACPI enabled!\n");
 
     print_cpu_id();
     io_sti();
diff --git a/kernel/task.c b/kernel/task.c
index a3584e6..a7a091f 100644
--- a/kernel/task.c
+++ b/kernel/task.c
@@ -62,12 +62,66 @@ void print_proc(){
     printf("Name          Pid     Status [All Proc: %d]\n\n",index);
 }
 
+static void found_task(int pid,struct task_struct *base,struct task_struct *argv){
+    struct task_struct *t = base;
+    if(t == NULL){
+        argv = NULL;
+        return;
+    }
+    if(t->pid == pid){
+        *argv = *t;
+        return;
+    } else{
+        found_task(pid,t->next,argv);
+    }
+}
+
+void task_kill(int pid){
+    struct task_struct *argv;
+    found_task(pid,running_proc_head,argv);
+    if(argv == NULL){
+        printf("Cannot found task Pid:[%d].\n",pid);
+        return;
+    }
+    if(argv->pid == 0){
+        printf("[\033kernel\036]: Taskkill cannot terminate kernel processes.\n");
+        return;
+    }
+    argv->state = TASK_DEATH;
+    switch (argv->state) {
+        case TASK_RUNNABLE:
+            printf("%s      %d     %s\n",argv->name,argv->pid,"Running");
+            break;
+        case TASK_SLEEPING:
+            printf("%s      %d     %s\n",argv->name,argv->pid,"Sleeping");
+            break;
+        case TASK_UNINIT:
+            printf("%s      %d     %s\n",argv->name,argv->pid,"Init");
+            break;
+        case TASK_ZOMBIE:
+            printf("%s      %d     %s\n",argv->name,argv->pid,"Zombie");
+            break;
+        case TASK_DEATH:
+            printf("%s      %d     %s\n",argv->name,argv->pid,"Death");
+            break;
+    }
+    printf("Task [%s] exit code: -130.\n",argv->name);
+
+    struct task_struct *head = running_proc_head;
+    struct task_struct *last = NULL;
+    while (1){
+        if(head->pid == argv->pid){
+            last->next = argv->next;
+            return;
+        }
+        last = head;
+        head = head->next;
+    }
+}
+
 void schedule() {
     if (current) {
-        volatile task_state state = current->next->state;
-        if(state == TASK_RUNNABLE || state == TASK_SLEEPING){
-            change_task_to(current->next);
-        }
+        change_task_to(current->next);
     }
 }
 
@@ -75,6 +129,7 @@ void change_task_to(struct task_struct *next) {
     if (current != next) {
         struct task_struct *prev = current;
         current = next;
+
         //switch_page_directory(current->pgd_dir);
         switch_to(&(prev->context), &(current->context));
     }
diff --git a/sysapp/shell.c b/sysapp/shell.c
index 447f54d..a865b3c 100644
--- a/sysapp/shell.c
+++ b/sysapp/shell.c
@@ -67,8 +67,25 @@ void cmd_echo(int argc, char **argv) {
     vga_putchar('\n');
 }
 
-void cmd_proc(){
-    print_proc();
+void cmd_proc(int argc, char **argv){
+    if (argc <= 1) {
+        printf("\033[Shell-PROC]: If there are too few parameters.\036\n");
+        return;
+    }
+
+    if(!strcmp("list",argv[1])){
+        print_proc();
+    } else if(!strcmp("kill",argv[1])){
+        if (argc <= 2) {
+            printf("\033[Shell-PROC-kill]: If there are too few parameters.\036\n");
+            return;
+        }
+        int pid = strtol(argv[2],NULL,10);
+        task_kill(pid);
+    } else{
+        printf("\033[Shell-[PROC]]: Unknown parameter\036\n");
+        return;
+    }
 }
 
 void cmd_date(){
@@ -195,7 +212,7 @@ void setup_shell(){
         else if (!strcmp("clear", argv[0]))
             vga_clear();
         else if (!strcmp("proc", argv[0]))
-            cmd_proc();
+            cmd_proc(argc, argv);
         else if (!strcmp("sysinfo", argv[0]))
             cmd_date();
         else if (!strcmp("ls", argv[0]))
@@ -212,17 +229,17 @@ void setup_shell(){
             cmd_reset();
         else if (!strcmp("help", argv[0]) || !strcmp("?", argv[0]) || !strcmp("h", argv[0])) {
             vga_writestring("-=[\037CrashPowerShell Helper\036]=-\n");
-            vga_writestring("help ? h           \032Print shell help info.\036\n");
-            vga_writestring("version            \032Print os version.\036\n");
-            vga_writestring("echo       <msg>   \032Print message.\036\n");
-            vga_writestring("ls                 \032List all files.\036\n");
-            vga_writestring("cat <name> <util>  \032Edit a file.\036\n");
-            vga_writestring("read       <name>  \032Read a file.\036\n");
-            vga_writestring("mkdir      <name>  \032Make a directory.\036\n");
-            vga_writestring("del rm     <name>  \032Delete a file.\036\n");
-            vga_writestring("sysinfo            \032Print system info.\036\n");
-            vga_writestring("proc               \032Lists all running processes.\036\n");
-            vga_writestring("reset              \032Reset OS.\036\n");
+            vga_writestring("help ? h              \032Print shell help info.\036\n");
+            vga_writestring("version               \032Print os version.\036\n");
+            vga_writestring("echo       <msg>      \032Print message.\036\n");
+            vga_writestring("ls                    \032List all files.\036\n");
+            vga_writestring("cat <name> <util>     \032Edit a file.\036\n");
+            vga_writestring("read       <name>     \032Read a file.\036\n");
+            vga_writestring("mkdir      <name>     \032Make a directory.\036\n");
+            vga_writestring("del rm     <name>     \032Delete a file.\036\n");
+            vga_writestring("sysinfo               \032Print system info.\036\n");
+            vga_writestring("proc [kill<pid>|list] \032Lists all running processes.\036\n");
+            vga_writestring("reset                 \032Reset OS.\036\n");
         } else printf("\033[Shell]: Unknown command '%s'.\036\n", argv[0]);
     }
 }
diff --git a/util/common.c b/util/common.c
index a358442..28da1c4 100644
--- a/util/common.c
+++ b/util/common.c
@@ -5,6 +5,73 @@
 
 static char num_str_buf[BUF_SIZE];
 
+long int strtol(const char *str,char **endptr,int base){
+    const char *s;
+    unsigned long acc;
+    char c;
+    unsigned long cutoff;
+    int neg, any, cutlim;
+    s = str;
+    do {
+        c = *s++;
+    } while (isspace((unsigned char)c));
+    if (c == '-') {
+        neg = 1;
+        c = *s++;
+    } else {
+        neg = 0;
+        if (c == '+')
+            c = *s++;
+    }
+    if ((base == 0 || base == 16) &&
+        c == '0' && (*s == 'x' || *s == 'X') &&
+        ((s[1] >= '0' && s[1] <= '9') ||
+         (s[1] >= 'A' && s[1] <= 'F') ||
+         (s[1] >= 'a' && s[1] <= 'f'))) {
+        c = s[1];
+        s += 2;
+        base = 16;
+    }
+    if (base == 0)
+        base = c == '0' ? 8 : 10;
+    acc = any = 0;
+    if (base < 2 || base > 36)
+        goto noconv;
+
+    cutoff = neg ? (unsigned long)-(LONG_MIN + LONG_MAX) + LONG_MAX
+                 : LONG_MAX;
+    cutlim = cutoff % base;
+    cutoff /= base;
+    for ( ; ; c = *s++) {
+        if (c >= '0' && c <= '9')
+            c -= '0';
+        else if (c >= 'A' && c <= 'Z')
+            c -= 'A' - 10;
+        else if (c >= 'a' && c <= 'z')
+            c -= 'a' - 10;
+        else
+            break;
+        if (c >= base)
+            break;
+        if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
+            any = -1;
+        else {
+            any = 1;
+            acc *= base;
+            acc += c;
+        }
+    }
+    if (any < 0) {
+        acc = neg ? LONG_MIN : LONG_MAX;
+    } else if (!any) {
+        noconv:
+    } else if (neg)
+        acc = -acc;
+    if (endptr != NULL)
+        *endptr = (char *)(any ? s - 1 : str);
+    return (acc);
+}
+
 size_t strnlen(const char *s, size_t maxlen) {
     const char *es = s;
     while (*es && maxlen) {