diff --git a/kernel/kernel.cpp b/kernel/kernel.cpp
index 5c870ad..25b7456 100644
--- a/kernel/kernel.cpp
+++ b/kernel/kernel.cpp
@@ -3,6 +3,13 @@
 
 #include <opensbi/opensbi.h>
 #include <opensbi/extensions/legacy.h>
+#include <opensbi/extensions/base.h>
+#include <opensbi/extensions/timer.h>
+#include <opensbi/extensions/ipi.h>
+#include <opensbi/extensions/rfence.h>
+#include <opensbi/extensions/hsm.h>
+#include <opensbi/extensions/srst.h>
+#include <opensbi/extensions/pmu.h>
 
 #define read_csr(csr) \
     ({ \
@@ -32,13 +39,13 @@
 typedef unsigned long sbi_word;
 
 void fmt(const char *f, ...) {
-    using drivers::opensbi::legacy::console_putchar;
+    namespace legacy = drivers::opensbi::legacy;
 
     va_list va;
     va_start(va, f);
     while(*f) {
         if(*f != '{') {
-            console_putchar(*(f++));
+            legacy::console_putchar(*(f++));
             continue;
         }
         f++;
@@ -54,7 +61,7 @@ void fmt(const char *f, ...) {
         for(int i = 0; i < 16; ++i) {
             const char *digits = "0123456789abcdef";
             int d = (v >> (60 - i * 4)) & 0xF;
-            console_putchar(digits[d]);
+            legacy::console_putchar(digits[d]);
         }
     }
     va_end(va);
@@ -192,7 +199,8 @@ void switch_task(void *ctx, continuation_t c) {
 extern "C" void isr();
 
 extern "C" void handle_isr(isr_frame_t *frame) {
-    using drivers::opensbi::legacy::console_putchar;
+    namespace legacy = drivers::opensbi::legacy;
+    namespace timer = drivers::opensbi::timer;
 
     unsigned long cause = read_csr("scause");
     unsigned long code = cause & ~(1UL << 63);
@@ -203,20 +211,22 @@ extern "C" void handle_isr(isr_frame_t *frame) {
         }else if(code == 5) { // Timer interrupt.
             //clear_csr_bits("sie", sie_s_timer);
             unsigned long time = read_csr("time");
-            drivers::opensbi::ecall(0x54494D45, 0, time + 100000);
-            save_stack(switch_task, current_task);
+            //drivers::opensbi::ecall(0x54494D45, 0, time + 100000);
+            timer::set_timer(time + 10000000);
+            //set_timer(time + 100000);
+            //save_stack(switch_task, current_task);
         }else{
             fmt("it's an unhandled interrupt, code: {}\n", code);
         }
     }else{
         if(code == 8) { // Syscall.
-            console_putchar(frame->a[0]);
+            legacy::console_putchar(frame->a[0]);
         }else{
             unsigned long sepc = read_csr("sepc");
             fmt("it's an exception at {}\n", sepc);
             const char *s = exception_strings[cause];
             while(*s)
-                console_putchar(*(s++));
+                legacy::console_putchar(*(s++));
             while(1)
                 ;
         }
@@ -266,10 +276,56 @@ extern "C" void kmain(unsigned long hart, void *dtb) {
     (void)hart;
     (void)dtb;
 
-    using drivers::opensbi::legacy::console_putchar;
+    namespace legacy = drivers::opensbi::legacy;
+    namespace base = drivers::opensbi::base;
+    namespace timer = drivers::opensbi::timer;
+    namespace ipi = drivers::opensbi::ipi;
 
     fmt("test\n");
 
+    auto ret = base::get_spec_version();
+    if(ret.error) {
+        fmt("get_spec_version failed\n");
+    } else {
+        fmt("spec version: {}\n", ret.value);
+    }
+
+    ret = base::get_impl_id();
+    if(ret.error) {
+        fmt("get_impl_id failed\n");
+    } else {
+        fmt("impl id: {}\n", ret.value);
+    }
+
+    ret = base::get_impl_version();
+    if(ret.error) {
+        fmt("get_impl_version failed\n");
+    } else {
+        fmt("impl version: {}\n", ret.value);
+    }
+
+    ret = base::get_mvendor_id();
+    if(ret.error) {
+        fmt("get_mvendor_id failed\n");
+    } else {
+        fmt("vendor id: {}\n", ret.value);
+    }
+
+    ret = base::get_march_id();
+    if(ret.error) {
+        fmt("get_march_id failed\n");
+    } else {
+        fmt("arch id: {}\n", ret.value);
+    }
+
+    ret = base::get_mimp_id();
+    if(ret.error) {
+        fmt("get_mimp_id failed\n");
+    } else {
+        fmt("imp id: {}\n", ret.value);
+    }
+
+
     fmt("uintmax: {} bits\n", sizeof(uintmax_t) * 8);
     fmt("HART: {}, DTB: {}\n", hart, dtb);
 
@@ -279,7 +335,7 @@ extern "C" void kmain(unsigned long hart, void *dtb) {
     *cfg = 0x10;
     *dat = 0xFF;
 
-    while(1);
+    //while(1);
 
     cli();
 
@@ -292,9 +348,28 @@ extern "C" void kmain(unsigned long hart, void *dtb) {
     set_csr_bits("sie", sie_s_software | sie_s_timer);
 
     // Self-IPI.
-    drivers::opensbi::ecall(0x735049, 0, 1 << hart, 0);
+    ipi::send_ipi({ 1UL << hart, 0 });
 
     sti();
+    unsigned long timea = read_csr("time");
+    ret = timer::set_timer(timea + 100000);
+
+    drivers::opensbi::rfence::remote_fence_i({0, 0});
+    //ret = drivers::opensbi::hsm::hart_stop();
+    using drivers::opensbi::srst::ResetType;
+    using drivers::opensbi::srst::ResetReason;
+    // ret = drivers::opensbi::srst::system_reset(ResetType::WARM_REBOOT, ResetReason::SYSTEM_FAILURE);
+
+    namespace pmu = drivers::opensbi::pmu;
+    ret = pmu::num_counters();
+
+    fmt("Number of counters: {}\n", ret.value);
+    for(int i = 0; i < ret.value; i++) {
+        ret = pmu::counter_get_info(i);
+        fmt("{} err: {}\n", i, ret.error);
+        fmt("{} val: {}\n", i, ret.value);
+    }
+    while(1);
     cli();
 
     unsigned long time;
@@ -325,17 +400,21 @@ extern "C" void kmain(unsigned long hart, void *dtb) {
     s = "paging works!\n";
     s += 512UL * 1024 * 1024 * 1024;
     while(*s)
-        console_putchar(*(s++));
+        legacy::console_putchar(*(s++));
 
     create_task(&task1, task1_main);
     create_task(&task2, task2_main);
 
     time = read_csr("time");
-    drivers::opensbi::ecall(0x54494D45, 0, time + 100000);
+    //set_timer(time + 100000);
+    //drivers::opensbi::ecall(0x54494D45, 0, time + 100000);
+    //timer::set_timer(time + 100000);
 
-    save_stack(switch_task, 0);
+    //save_stack(switch_task, 0);
 
-    drivers::opensbi::ecall(8, 0, 0);
+    namespace hsm = drivers::opensbi::hsm;
+    hsm::hart_stop();
+    // drivers::opensbi::ecall(8, 0, 0);
 
     while(1);
 }