diff --git a/bsp/x86/bootsector.s b/bsp/x86/bootsector.s
index faa175a..5d37724 100644
--- a/bsp/x86/bootsector.s
+++ b/bsp/x86/bootsector.s
@@ -3,7 +3,7 @@
 
 CYLS = 10
 BOOTSEG =   0x07C0
-INITSEG =   0x7000
+INITSEG =   0x0050
 SYSSEG  =   0x1000
 .code16
 .section ".bstext", "ax"
@@ -21,7 +21,7 @@ main_start:
 	xorw	%sp, %sp
 
     
-#move BootSector to 0x9000(INITSEG)
+#move BootSector to INITSEG
 #
     movw $BOOTSEG, %ax
     movw %ax,   %ds
@@ -181,6 +181,8 @@ fin:
     mov $0x13,%al
     int $0x10
 #
+#Jump into INITSEG, rather than SYSSEG, because
+#We want to store e820 at $INITSEG:$E820_OFFSET. Our SYSSEG(0x1000) as real start
     ljmp $INITSEG, $lowlevel_init
     hlt
 
diff --git a/bsp/x86/lowlevel_init.s b/bsp/x86/lowlevel_init.s
index 63ff8c1..2bee9d3 100644
--- a/bsp/x86/lowlevel_init.s
+++ b/bsp/x86/lowlevel_init.s
@@ -81,7 +81,7 @@ _lowlevel_init:
     nop;
     nop;
     
-#Get memory map and store memroy table start from  0x00098004, each entry has 20bytes data but
+#Get memory map and store memroy table start from  $INITSEG:1004, each entry has 20bytes data but
 #currently we reserve 0x20 bytes for each entry
 #Each entry has :
 #First uint64_t = Base address
@@ -93,7 +93,8 @@ _lowlevel_init:
 #   Type 4: ACPI NVS memory
 #   Type 5: Area containing bad memory
 #Set register base https://wiki.osdev.org/Detecting_Memory_(x86)
-    mov $0x8004, %di
+	E820_OFFSET=0x1004
+    mov $E820_OFFSET, %di
     xor %ebx, %ebx
     mov $0x0534D4150, %edx
     mov $0xe820,%eax
@@ -107,8 +108,6 @@ get_next:
     int $0x15
     cmp $0, %ebx /*ebx=0 means no other entry*/
     jnz get_next
-#for debug
-#    hlt
 
 #Inital Serial Device 1
 #com1 at 0x3F8
@@ -185,7 +184,7 @@ fin:
     hlt
     jmp fin
 
-INITSEG = 0x7000
+INITSEG  = 0x0050
 
 idt_ptr:
     .word   0       /* limit */
diff --git a/include/common.h b/include/common.h
index 3c50421..43a6f61 100644
--- a/include/common.h
+++ b/include/common.h
@@ -25,6 +25,7 @@ extern struct bitmap_font font;
 unsigned int memtest(unsigned int start, unsigned int end);
 
 #define SYSSEG  0x1000
+#define INITSEG  0x0050
 #define MEMMAN_ADDR (char *)((0x003c0000) - (SYSSEG << 4))
 #define VRAM_ADDR (unsigned char *)((0xa0000)-(SYSSEG << 4))
 #define COL8_000000     0
@@ -43,7 +44,8 @@ unsigned int memtest(unsigned int start, unsigned int end);
 #define COL8_840084     13
 #define COL8_008484     14
 #define COL8_848484     15
-#define MEM_MAP_ADDR (char *)((0x00078004)-(SYSSEG << 4))
+#define E820_OFFSET     0x1004
+#define MEM_MAP_ADDR (char *)((INITSEG << 4)+(E820_OFFSET)-(SYSSEG << 4))
 
 struct SEGMENT_DESCRIPTOR {
 	short limit_low, base_low;