I am going to write a simple operating system. An error have been occurred while switch from 16 bits' real mode to 32 bits' protected mode.
After loading the GDT register and setting the GDT, the protected mode has been turned on successfully. I'd like to jump to 0x0 address in memory but failed and the information of GDT shows that there are thousands of GDT describer.
'''
lgdt (gdt_48 - _start + 0x7c00)
movw $0x1, %ax
lmsw %ax // switch protect mode on
jmp $0x8, $0x0 // jmp 0:0
gdt:
.word 0, 0, 0, 0
.word 0x07ff
.word 0x0000
.word 0x9a00
.word 0x00c0
.word 0x07ff
.word 0x0000
.word 0x9200
.word 0x00c0
gdt_48:
.word 0x7ff // 2048/8=256
.word gdt, 0
'''
Here is debug info:
