diff --git a/Makefile b/Makefile
index 99db2da..f2b989e 100644
--- a/Makefile
+++ b/Makefile
@@ -72,6 +72,7 @@ CFLAGS += $(shell $(CC) -fno-stack-protector -E -x c /dev/null >/dev/null 2>&1 &
 LDFLAGS = -z max-page-size=4096
 
 linker = ./linker/k210.ld
+# linker = ./linker/xv6.ld
 
 # LDFLAGS = -Wl,--build-id=none -nostartfiles -nostdlib -static -fno-stack-protector
 # LIBS				:= -lgcc
diff --git a/doc/s_extern_interrupt.md b/doc/s_extern_interrupt.md
index 42a388b..51b6b67 100644
--- a/doc/s_extern_interrupt.md
+++ b/doc/s_extern_interrupt.md
@@ -76,7 +76,7 @@ supervisor_external_handler() {
 ...
 
 // 使用 SBI 调用注册 S 态外部中断处理函数
-sbi_set_extern_interrupt((uint64)supervisor_external_handler - 0xffffffff00000000);
+sbi_set_extern_interrupt((uint64)supervisor_external_handler);
 ```
 
 这样做看起来很简单，是因为 luojia 在 RustSBI 中针对 K210 这个平台做的特定的功能，如果是 OpenSBI 就达不到这种效果。这么做的原理我这里直接引用吴一凡学长的笔记：  
diff --git a/kernel/entry_k210.S b/kernel/entry_k210.S
index 4dd1dc9..f5d2378 100644
--- a/kernel/entry_k210.S
+++ b/kernel/entry_k210.S
@@ -3,16 +3,21 @@
 _start:
     add t0, a0, 1
     slli t0, t0, 14
-    lui sp, %hi(boot_stack)
+    // lui sp, %hi(boot_stack)
+	la sp, boot_stack
     add sp, sp, t0
 
     // add by retrhelo, write tp reg 
-    //csrr t1, mhartid 
-    //mv tp, t1
+    // csrr t1, mhartid 
+    // mv tp, t1
 
-    lui t0, %hi(main)
-    addi t0, t0, %lo(main)
-    jr t0
+    // lui t0, %hi(main)
+    // addi t0, t0, %lo(main)
+    // jr t0
+    call main
+
+loop:
+    j loop
 
     .section .bss.stack
     .align 12
diff --git a/kernel/include/param.h b/kernel/include/param.h
index 7d338b1..c1be2cc 100644
--- a/kernel/include/param.h
+++ b/kernel/include/param.h
@@ -1,4 +1,4 @@
-#define NPROC        64  // maximum number of processes
+#define NPROC        16  // maximum number of processes
 #define NCPU          8  // maximum number of CPUs
 #define NOFILE       16  // open files per process
 #define NFILE       100  // open files per system
diff --git a/kernel/include/riscv.h b/kernel/include/riscv.h
index 4e5efbf..7eee34a 100644
--- a/kernel/include/riscv.h
+++ b/kernel/include/riscv.h
@@ -319,7 +319,6 @@ sfence_vma()
 {
   // the zero, zero means flush all TLB entries.
   // asm volatile("sfence.vma zero, zero");
-  // asm volatile("sfence.vm");
   asm volatile("sfence.vma");
 }
 
diff --git a/kernel/include/syscall.h b/kernel/include/syscall.h
index bc5f356..4dd9473 100644
--- a/kernel/include/syscall.h
+++ b/kernel/include/syscall.h
@@ -20,3 +20,4 @@
 #define SYS_link   19
 #define SYS_mkdir  20
 #define SYS_close  21
+#define SYS_test 22
diff --git a/kernel/kalloc.c b/kernel/kalloc.c
index b664e1a..18c9f36 100644
--- a/kernel/kalloc.c
+++ b/kernel/kalloc.c
@@ -28,8 +28,8 @@ void
 kinit()
 {
   initlock(&kmem.lock, "kmem");
-  printf("kernel_end: %p, phystop: %p\n", kernel_end - 0xffffffff00000000, (void*)PHYSTOP);
-  freerange(kernel_end - 0xffffffff00000000, (void*)PHYSTOP);
+  printf("kernel_end: %p, phystop: %p\n", kernel_end, (void*)PHYSTOP);
+  freerange(kernel_end, (void*)PHYSTOP);
   printf("kinit\n");
 }
 
@@ -51,7 +51,7 @@ kfree(void *pa)
 {
   struct run *r;
   
-  if(((uint64)pa % PGSIZE) != 0 || (char*)pa < kernel_end - 0xffffffff00000000 || (uint64)pa >= PHYSTOP)
+  if(((uint64)pa % PGSIZE) != 0 || (char*)pa < kernel_end || (uint64)pa >= PHYSTOP)
     panic("kfree");
 
   // Fill with junk to catch dangling refs.
diff --git a/kernel/main.c b/kernel/main.c
index 8ac0a08..ba4b50c 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -34,19 +34,19 @@ main(unsigned long hartid, unsigned long dtb_pa)
     timerinit();     // set up timer interrupt handler
     procinit();
     device_init(dtb_pa, hartid);
-    fpioa_pin_init();
-    sdcard_init();
+    // fpioa_pin_init();
+    // sdcard_init();
     //plicinit();      // set up interrupt controller
     //plicinithart();  // ask PLIC for device interrupts
-    binit();         // buffer cache
-    iinit();         // inode cache
-    fileinit();      // file table
+    // binit();         // buffer cache
+    // iinit();         // inode cache
+    // fileinit();      // file table
     //virtio_disk_init(); // emulated hard disk
-    userinit();      // first user process
+    // userinit();      // first user process
+    test_proc_init();   // test porc init
 
     // test_kalloc();    // test kalloc
-    test_vm(hartid);       // test kernel pagetable
-    // test_proc_init();   // test porc init
+    // test_vm(hartid);       // test kernel pagetable
     // test_sdcard();
 
     printf("hart 0 init done\n");
diff --git a/kernel/proc.c b/kernel/proc.c
index 0b15ecd..3372d7d 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -24,45 +24,6 @@ static void freeproc(struct proc *p);
 extern char trampoline[]; // trampoline.S
 
 void reg_info(void) {
-  // struct proc *p = myproc();
-  // printf("trapframe {\n");
-  // printf("  kernel_satp: %p\n", p->trapframe->kernel_satp);
-  // printf("  kernel_sp: %p\n", p->trapframe->kernel_sp);
-  // printf("  kernel_trap: %p\n", p->trapframe->kernel_trap);
-  // printf("  kernel_hartid: %p\n", p->trapframe->kernel_hartid);
-  // printf("  epc: %p\n", p->trapframe->epc);
-  // printf("  ra: %p\n", p->trapframe->ra);
-  // printf("  sp: %p\n", p->trapframe->sp);
-  // printf("  gp: %p\n", p->trapframe->gp);
-  // printf("  tp: %p\n", p->trapframe->tp);
-  // printf("  t0: %p\n", p->trapframe->t0);
-  // printf("  t1: %p\n", p->trapframe->t1);
-  // printf("  t2: %p\n", p->trapframe->t2);
-  // printf("  s0: %p\n", p->trapframe->s0);
-  // printf("  s1: %p\n", p->trapframe->s1);
-  // printf("  a0: %p\n", p->trapframe->a0);
-  // printf("  a1: %p\n", p->trapframe->a1);
-  // printf("  a2: %p\n", p->trapframe->a2);
-  // printf("  a3: %p\n", p->trapframe->a3);
-  // printf("  a4: %p\n", p->trapframe->a4);
-  // printf("  a5: %p\n", p->trapframe->a5);
-  // printf("  a6: %p\n", p->trapframe->a6);
-  // printf("  a7: %p\n", p->trapframe->a7);
-  // printf("  s2: %p\n", p->trapframe->s2);
-  // printf("  s3: %p\n", p->trapframe->s3);
-  // printf("  s4: %p\n", p->trapframe->s4);
-  // printf("  s5: %p\n", p->trapframe->s5);
-  // printf("  s6: %p\n", p->trapframe->s6);
-  // printf("  s7: %p\n", p->trapframe->s7);
-  // printf("  s8: %p\n", p->trapframe->s8);
-  // printf("  s9: %p\n", p->trapframe->s9);
-  // printf("  s10: %p\n", p->trapframe->s10);
-  // printf("  s11: %p\n", p->trapframe->s11);
-  // printf("  t3: %p\n", p->trapframe->t3);
-  // printf("  t4: %p\n", p->trapframe->t4);
-  // printf("  t5: %p\n", p->trapframe->t5);
-  // printf("  t6: %p\n", p->trapframe->t6);
-  // printf("}\n");
   printf("register info: {\n");
   printf("sstatus: %p\n", r_sstatus());
   printf("sip: %p\n", r_sip());
@@ -268,74 +229,55 @@ uchar initcode[] = {
   0x00, 0x00, 0x00, 0x00
 };
 
-
-uchar proc_test_code_1[] = {
-  0x13, 0x05, 0x10, 0x04, 0x93, 0x05, 0x00, 0x00, 0x13, 0x06, 0x00, 0x00, 0x93, 0x06, 0x00, 0x00,
-  0x93, 0x08, 0x10, 0x00, 0x73, 0x00, 0x00, 0x00, 0xef, 0x00, 0x00, 0x00
+uchar printhello[] = {
+    0x13, 0x00, 0x00, 0x00,     // nop
+    0x13, 0x00, 0x00, 0x00,     // nop 
+    0x13, 0x00, 0x00, 0x00,     // nop 
+    // <start>
+    0x17, 0x05, 0x00, 0x00,     // auipc a0, 0x0 
+    0x13, 0x05, 0x05, 0x00,     // mv a0, a0 
+    0x93, 0x08, 0x60, 0x01,     // li a7, 22 
+    0x73, 0x00, 0x00, 0x00,     // ecall 
+    0xef, 0xf0, 0x1f, 0xff,     // jal ra, <start>
+    // <loop>
+    0xef, 0x00, 0x00, 0x00,     // jal ra, <loop>
 };
 
-uchar proc_test_code_2[] = {
-  0x13, 0x05, 0x20, 0x04, 0x93, 0x05, 0x00, 0x00, 0x13, 0x06, 0x00, 0x00, 0x93, 0x06, 0x00, 0x00,
-  0x93, 0x08, 0x10, 0x00, 0x73, 0x00, 0x00, 0x00, 0xef, 0x00, 0x00, 0x00
-};
-
-uchar proc_test_code_3[] = {
-  0x13, 0x05, 0x30, 0x04, 0x93, 0x05, 0x00, 0x00, 0x13, 0x06, 0x00, 0x00, 0x93, 0x06, 0x00, 0x00,
-  0x93, 0x08, 0x10, 0x00, 0x73, 0x00, 0x00, 0x00, 0xef, 0x00, 0x00, 0x00
-};
-
-uchar proc_test_code_4[] = {
-  0x13, 0x05, 0x40, 0x04, 0x93, 0x05, 0x00, 0x00, 0x13, 0x06, 0x00, 0x00, 0x93, 0x06, 0x00, 0x00,
-  0x93, 0x08, 0x10, 0x00, 0x73, 0x00, 0x00, 0x00, 0xef, 0x00, 0x00, 0x00
-};
 
 void test_proc_init() {
-  struct proc *p1;
+  struct proc *p;
 
-  p1 = allocproc();
-  uvminit(p1->pagetable, proc_test_code_1, sizeof(proc_test_code_1));
-  // initproc = p1;
-  p1->sz = PGSIZE;
-  p1->trapframe->epc = 0;      // user program counter
-  p1->trapframe->sp = PGSIZE;  // user stack pointer
-  safestrcpy(p1->name, "proc_test_code_1", sizeof(p1->name));
-  p1->cwd = namei("/test");
-  p1->state = RUNNABLE;
-  release(&p1->lock);
-  printf("[test_proc_init]allocproc: %p\n", p1);
+    p = allocproc();
+    initproc = p;
 
-  // struct proc *p2;
-  // p2 = allocproc();
-  // uvminit(p2->pagetable, proc_test_code_2, sizeof(proc_test_code_2));
-  // p2->sz = PGSIZE;
-  // p2->trapframe->epc = 0;      // user program counter
-  // p2->trapframe->sp = PGSIZE;  // user stack pointer
-  // safestrcpy(p2->name, "proc_test_code_2", sizeof(p2->name));
-  // p2->cwd = namei("/test");
-  // p2->state = RUNNABLE;
-  // release(&p2->lock);
+    uvminit(p->pagetable, (uchar*)printhello, sizeof(printhello));
+    p->sz = PGSIZE;
 
-  // struct proc *p3;
-  // p3 = allocproc();
-  // uvminit(p3->pagetable, proc_test_code_3, sizeof(proc_test_code_3));
-  // p3->sz = PGSIZE;
-  // p3->trapframe->epc = 0;      // user program counter
-  // p3->trapframe->sp = PGSIZE;  // user stack pointer
-  // safestrcpy(p3->name, "proc_test_code_3", sizeof(p3->name));
-  // p3->cwd = namei("/test");
-  // p3->state = RUNNABLE;
-  // release(&p3->lock);
+    p->trapframe->epc = 0x0;
+    p->trapframe->sp = PGSIZE;
 
-  // struct proc *p4;
-  // p4 = allocproc();
-  // uvminit(p4->pagetable, proc_test_code_4, sizeof(proc_test_code_4));
-  // p4->sz = PGSIZE;
-  // p4->trapframe->epc = 0;      // user program counter
-  // p4->trapframe->sp = PGSIZE;  // user stack pointer
-  // safestrcpy(p4->name, "proc_test_code_4", sizeof(p4->name));
-  // p4->cwd = namei("/test");
-  // p4->state = RUNNABLE;
-  // release(&p4->lock);
+    safestrcpy(p->name, "test_code_0", sizeof(p->name));
+
+    p->state = RUNNABLE;
+
+    release(&p->lock);
+
+	struct proc *p1;
+
+    p1 = allocproc();
+    printf("return from allocproc()\n");
+
+    uvminit(p1->pagetable, (uchar*)printhello, sizeof(printhello));
+    p1->sz = PGSIZE;
+
+    p1->trapframe->epc = 0x0;
+    p1->trapframe->sp = PGSIZE;
+
+    safestrcpy(p1->name, "test_code_1", sizeof(p1->name));
+
+    p1->state = RUNNABLE;
+
+    release(&p1->lock);
 
   printf("[test_proc]test_proc init done\n");
 }
@@ -352,7 +294,7 @@ userinit(void)
   // allocate one user page and copy init's instructions
   // and data into it.
   // uvminit(p->pagetable, initcode, sizeof(initcode));
-  uvminit(p->pagetable, proc_test_code_1, sizeof(proc_test_code_1));
+  uvminit(p->pagetable, initcode, sizeof(initcode));
   p->sz = PGSIZE;
 
   // prepare for the very first "return" from kernel to user.
diff --git a/kernel/syscall.c b/kernel/syscall.c
index 073d4e5..4aeb51b 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -106,6 +106,7 @@ extern uint64 sys_unlink(void);
 extern uint64 sys_wait(void);
 extern uint64 sys_write(void);
 extern uint64 sys_uptime(void);
+extern uint64 sys_test(void);
 
 static uint64 (*syscalls[])(void) = {
 [SYS_fork]    sys_fork,
@@ -129,6 +130,7 @@ static uint64 (*syscalls[])(void) = {
 [SYS_link]    sys_link,
 [SYS_mkdir]   sys_mkdir,
 [SYS_close]   sys_close,
+[SYS_test]    sys_test,
 };
 
 void
@@ -146,3 +148,9 @@ syscall(void)
     p->trapframe->a0 = -1;
   }
 }
+
+uint64 
+sys_test(void) {
+    printf("%d: hello world\n", myproc()->pid);
+    return 0;
+}
\ No newline at end of file
diff --git a/kernel/test.c b/kernel/test.c
index a15f2d0..dd7e190 100644
--- a/kernel/test.c
+++ b/kernel/test.c
@@ -11,7 +11,7 @@
 #include "include/sbi.h"
 #include "include/sdcard.h"
 
-extern uint64 etext_addr;
+extern uint64 etext;
 extern struct proc *initproc;
 void test_kalloc() {
     char *mem = kalloc();
@@ -70,11 +70,11 @@ void test_vm(unsigned long hart_id) {
   printf("[test_vm](kvmpa) va: %p, pa: %p\n", KERNBASE + 0x1000, kvmpa(KERNBASE + 0x1000));
   printf("[test_vm](kvmpa) va: %p, pa: %p\n", KERNBASE + 0x2000, kvmpa(KERNBASE + 0x2000));
   printf("[test_vm](kvmpa) va: %p, pa: %p\n", KERNBASE + 0x3000, kvmpa(KERNBASE + 0x3000));
-  printf("[test_vm]etext_addr:\n");
-  printf("[test_vm](kvmpa) va: %p, pa: %p\n", etext_addr, kvmpa(etext_addr));
-  printf("[test_vm](kvmpa) va: %p, pa: %p\n", etext_addr + 0x1000, kvmpa(etext_addr + 0x1000));
-  printf("[test_vm](kvmpa) va: %p, pa: %p\n", etext_addr + 0x2000, kvmpa(etext_addr + 0x2000));
-  printf("[test_vm](kvmpa) va: %p, pa: %p\n", etext_addr + 0x3000, kvmpa(etext_addr + 0x3000));
+  printf("[test_vm]etext:\n");
+  printf("[test_vm](kvmpa) va: %p, pa: %p\n", etext, kvmpa(etext));
+  printf("[test_vm](kvmpa) va: %p, pa: %p\n", etext + 0x1000, kvmpa(etext + 0x1000));
+  printf("[test_vm](kvmpa) va: %p, pa: %p\n", etext + 0x2000, kvmpa(etext + 0x2000));
+  printf("[test_vm](kvmpa) va: %p, pa: %p\n", etext + 0x3000, kvmpa(etext + 0x3000));
   printf("[test_vm]trampoline:\n");
   printf("[test_vm](kvmpa) va: %p, pa: %p\n", TRAMPOLINE, kvmpa(TRAMPOLINE));
   printf("[test_vm](kvmpa) va: %p, pa: %p\n", TRAMPOLINE + PGSIZE - 1, kvmpa(TRAMPOLINE + PGSIZE - 1));
diff --git a/kernel/trampoline.S b/kernel/trampoline.S
index 057ef17..cb696a2 100644
--- a/kernel/trampoline.S
+++ b/kernel/trampoline.S
@@ -78,7 +78,7 @@ uservec:
         csrw satp, t1
 
         # sfence.vma zero, zero
-        sfence.vm
+        sfence.vma
 
         # a0 is no longer valid, since the kernel page
         # table does not specially map p->tf.
@@ -100,8 +100,7 @@ userret:
         csrw satp, a1
 
         # sfence.vma zero, zero
-        sfence.vm
-        # sfence.vma
+        sfence.vma
         
         # put the saved user a0 in sscratch, so we
         # can swap it with our a0 (TRAPFRAME) in the last step.
@@ -143,10 +142,6 @@ userret:
 	# restore user a0, and save TRAPFRAME in sscratch
         csrrw a0, sscratch, a0
 
-        lui t0, %hi(reg_info)
-        addi t0, t0, %lo(reg_info)
-        jr t0
-
         # return to user mode and user pc.
         # usertrapret() set up sstatus and sepc.
         sret
diff --git a/kernel/trap.c b/kernel/trap.c
index 555af60..7372370 100644
--- a/kernel/trap.c
+++ b/kernel/trap.c
@@ -19,11 +19,6 @@ void kernelvec();
 
 extern int devintr();
 
-void userret_log() {
-  printf("run in userret\n");
-  while (1) {}
-  
-}
 void
 trapinit(void)
 {
@@ -48,7 +43,7 @@ trapinithart(void)
 void
 usertrap(void)
 {
-  printf("run in usertrap\n");
+  // printf("run in usertrap\n");
   int which_dev = 0;
 
   if((r_sstatus() & SSTATUS_SPP) != 0)
@@ -133,19 +128,14 @@ usertrapret(void)
   w_sepc(p->trapframe->epc);
 
   // tell trampoline.S the user page table to switch to.
-  printf("[usertrapret]p->pagetable: %p\n", p->pagetable);
+  // printf("[usertrapret]p->pagetable: %p\n", p->pagetable);
   uint64 satp = MAKE_SATP(p->pagetable);
 
-  // reg_info();
   // jump to trampoline.S at the top of memory, which 
   // switches to the user page table, restores user registers,
   // and switches to user mode with sret.
   uint64 fn = TRAMPOLINE + (userret - trampoline);
-  printf("[usertrapret]fn va: %p, pa: %p\n", fn, kvmpa(fn));
-  printf("[usertrapret]useret: %p\n", ((uint64)userret & 0xffffffff));
-  // ((void (*)(uint64,uint64))fn)(TRAPFRAME, satp);
-  // use physical address `userret` instead of virtual address `fn`
-  ((void (*)(uint64,uint64))((uint64)userret & 0xffffffff))(TRAPFRAME, satp);
+  ((void (*)(uint64,uint64))fn)(TRAPFRAME, satp);
 }
 
 // interrupts and exceptions from kernel code go here via kernelvec,
@@ -234,7 +224,8 @@ devintr()
     // software interrupt from a supervisor-mode timer interrupt,
 
     if(cpuid() == 0){
-      clockintr();
+      // clockintr();
+      printf("[devintr]clockintr\n");
     }
     
     // acknowledge the software interrupt by clearing
@@ -278,6 +269,6 @@ void device_init(unsigned long pa, uint64 hartid) {
   uint32 *hart0_m_int_enable_hi = (uint32*)(PLIC_MENABLE(hartid) + 0x04);
   *(hart0_m_int_enable_hi) = (1 << 0x1);
   // *(uint32*)0x0c002004 = (1 << 0x1);
-  sbi_set_extern_interrupt((uint64)supervisor_external_handler - 0xffffffff00000000);
+  sbi_set_extern_interrupt((uint64)supervisor_external_handler);
   printf("device init\n");
 }
\ No newline at end of file
diff --git a/kernel/vm.c b/kernel/vm.c
index 51ed30f..7c98933 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -12,9 +12,7 @@
 pagetable_t kernel_pagetable;
 
 extern char etext[];  // kernel.ld sets this to end of kernel code.
-uint64 etext_addr = (uint64)etext - 0xffffffff00000000;
 extern char trampoline[]; // trampoline.S
-uint64 trampoline_addr = (uint64)trampoline - 0xffffffff00000000;
 /*
  * create a direct-map page table for the kernel.
  */
@@ -37,15 +35,14 @@ kvminit()
 
   // PLIC
   kvmmap(PLIC, PLIC, 0x400000, PTE_R | PTE_W);
-  // printf("kernel_base: %p, etext: %p, etext - kernel_base: %p\n", KERNBASE, etext_addr, etext_addr - KERNBASE);
   // map kernel text executable and read-only.
-  kvmmap(KERNBASE, KERNBASE, etext_addr - KERNBASE, PTE_R | PTE_X);
+  kvmmap(KERNBASE, KERNBASE, (uint64)etext - KERNBASE, PTE_R | PTE_X);
   // map kernel data and the physical RAM we'll make use of.
-  kvmmap(etext_addr, etext_addr, PHYSTOP - etext_addr, PTE_R | PTE_W);
+  kvmmap((uint64)etext, (uint64)etext, PHYSTOP - (uint64)etext, PTE_R | PTE_W);
 
   // map the trampoline for trap entry/exit to
   // the highest virtual address in the kernel.
-  kvmmap(TRAMPOLINE, trampoline_addr, PGSIZE, PTE_R | PTE_X);
+  kvmmap(TRAMPOLINE, (uint64)trampoline, PGSIZE, PTE_R | PTE_X);
   // kvmmap(TRAMPOLINE, (uint64)trampoline, PGSIZE, PTE_R | PTE_X);
 
   printf("kvminit\n");
@@ -228,8 +225,7 @@ uvminit(pagetable_t pagetable, uchar *src, uint sz)
   mem = kalloc();
   printf("[uvminit]kalloc: %p\n", mem);
   memset(mem, 0, PGSIZE);
-  // int map_res = mappages(pagetable, 0, PGSIZE, (uint64)mem, PTE_W|PTE_R|PTE_X|PTE_U);
-  // printf("[vminit]map result: %d, va: %p, pa: %p\n", map_res, PGSIZE - 1, walkaddr(pagetable, PGSIZE - 1) + PGSIZE - 1);
+  mappages(pagetable, 0, PGSIZE, (uint64)mem, PTE_W|PTE_R|PTE_X|PTE_U);
   memmove(mem, src, sz);
   for (int i = 0; i < sz; i ++) {
     printf("[uvminit]mem: %p, %x\n", mem + i, mem[i]);
diff --git a/linker/k210.ld b/linker/k210.ld
index adadc4d..d2102b7 100644
--- a/linker/k210.ld
+++ b/linker/k210.ld
@@ -1,7 +1,7 @@
 OUTPUT_ARCH(riscv)
 ENTRY(_start)
 
-BASE_ADDRESS = 0xffffffff80020000;
+BASE_ADDRESS = 0x80020000;
 
 SECTIONS
 {