Li-Ta Lo ollie@lanl.gov writes:
Eric,
Why we use two differenct segment lay out for pre-C and C part ?
For the code that runs from ram and the code that runs directly from the rom chip.
In entry32.inc it is 0x08 for code and 0x10 for data but in c_start we use 0x10 for code and 0x18 for data.
Good question but it is probably a decent thing that will keep up from making too many assumptions that they have the same gdt.
I don't believe this is something that has changed recently.
Eric
On Tue, 2004-11-02 at 16:23, Eric W. Biederman wrote:
Li-Ta Lo ollie@lanl.gov writes:
Eric,
Why we use two differenct segment lay out for pre-C and C part ?
For the code that runs from ram and the code that runs directly from the rom chip.
In entry32.inc it is 0x08 for code and 0x10 for data but in c_start we use 0x10 for code and 0x18 for data.
Good question but it is probably a decent thing that will keep up from making too many assumptions that they have the same gdt.
I don't believe this is something that has changed recently.
It is there for a long time. I just want to know why.
Ollie
Eric
Li-Ta Lo ollie@lanl.gov writes:
On Tue, 2004-11-02 at 16:23, Eric W. Biederman wrote:
Li-Ta Lo ollie@lanl.gov writes:
Eric,
Why we use two differenct segment lay out for pre-C and C part ?
For the code that runs from ram and the code that runs directly from the rom chip.
In entry32.inc it is 0x08 for code and 0x10 for data but in c_start we use 0x10 for code and 0x18 for data.
Good question but it is probably a decent thing that will keep up from making too many assumptions that they have the same gdt.
I don't believe this is something that has changed recently.
It is there for a long time. I just want to know why.
To be clear I think it was because we were confusing which gdt was which at some point. With different segment values we cannot have that confusion. And if you are actually mucking with segments I think not confusing the two is important.
Eric
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Li-Ta Lo