Re: [Qemu-discuss] How to check cpu running mode?

[krishnaLee]

Jakob:
I need more help,just now,I'm trigger a page fault in 64-bit mode,see this 
picture:
https://github.com/krishna116/test/blob/master/test-qemu-in-64bit-mode.png


so I can write some system mode code accroding to this information,
but my follow code seems can't get the right answer, is my algorithm wrong?


//this is my algorithm in 64-bit mode:
#define CS_L_BIT 0x1<<(32+22-1)
//CS_selector_index=0x7;                     //0x38>>3
//GDTR_base=0x7E90000;                       //0x7e9f598&~0xffff
int64* segment_descriptor_address=(int64*)(int64) (*(0x7E90000+0x7*8*2));  
//GDTR_base+CS_selector_index* sizeof(Segment_Descriptor*2)
if((*segment_descriptor_address)&CS_L_BIT)
{
//it is 64bit mode
}else
{
//it is Compatibility mode
}



thank you,
krishna