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Re: [Xen-devel] assembly language use in xen

I doubt the AT&T syntax is the most significant hurdle. The entry stubs are hidden away in macros in include/asm-x86/x86_32/asm_defns.h, and instantiated at the top of arch/x86/i8259.c. They get poked into the IDT in the first for() loop in init_IRQ().

 -- Keir

On 24/12/2008 12:54, "Furquan Shaikh" <furquan.m.shaikh@xxxxxxxxx> wrote:

Hello Keir,
Thanks a lot for the information.
I am having a tough time understanding the interrupt handling part in Xen as AT&T syntax is new for me.
Could you please give me a brief overview of the flow of control when control is transferred to Xen after interrupt?
Your guidance would be a lot of help for me.

Thanking you


On Wed, Dec 24, 2008 at 5:16 PM, Keir Fraser <keir.fraser@xxxxxxxxxxxxx> wrote:
On 24/12/2008 11:29, "Furquan Shaikh" <furquan.m.shaikh@xxxxxxxxx <http://furquan.m.shaikh@xxxxxxxxx> > wrote:

Is .text 1 the same as .section???

.text 1 occurs in entry.S

Please tell me what it means?

It specifies a numeric subsection. It's still part of the text section, but it will presumably be placed after the normal part of the text section. It's being used here to place rarely used code out of line. It also means that straight-line flow of control skips to the next instance of .previous, without needing an extra JMP instruction. Tricky code. :-)

 -- Keir

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