[ECOS] Question about fixed vector table(ARM).

HuangQiang jameshq@liverpool.ac.uk
Thu May 16 01:56:00 GMT 2002


Thank you very much. I still have one question about the fixed vector table.
In ARM vectors.s file takes care of the vector table(from 0x00) setup and
fixed vector table(from 0x20) setup. While branch to the vector it first
branch to the vector table(from 0x00) and then directed to fixed vector
table(from 0x20) then to the actual services routine. Why this fixed vector
table is needed here? Can't we just setup the vector table (from 0x00) and
branch to the services routine indirection of fixed vector table?

Thank you very much.

best regards!

james

-----Original Message-----
From: jlarmour@cambridge.redhat.com [mailto:jlarmour@cambridge.redhat.com]On
Behalf Of Jonathan Larmour
Sent: 14 May 2002 22:24
To: HuangQiang
Cc: eCos
Subject: Re: [ECOS] Does the fixed_vector section have anything to do with
the virtual vector table?


HuangQiang wrote:
>
> Hi all:
> Question as subject. Thank you for your reply.

Not at all. Virtual vectors are "soft" vectors - purely there for things
that software requires. They're nothing to do with hardware devices. That's
why, for example, the virtual vector table layout is the same for every
ecos target.

Jifl
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