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Re: What's exact meaning of CYGARC_HAL_SAVE_GP() function?Thanks
- From: Jonathan Larmour <jifl at eCosCentric dot com>
- To: Qiang Huang <jameshq at liverpool dot ac dot uk>
- Cc: Ecos-Discuss <ecos-discuss at sources dot redhat dot com>
- Date: Mon, 10 Feb 2003 23:20:36 +0000
- Subject: Re: [ECOS] What's exact meaning of CYGARC_HAL_SAVE_GP() function?Thanks
- References: <BDEPKKELILOKGOAOMONOIEGICBAA.jameshq@liv.ac.uk>
Qiang Huang wrote:
> Hi all:
> For Virtual Vector support what's the exact usage(meaning) of
> CYGARC_HAL_SAVE_GP() function? Thanks a lot
Some architectures, possibly only MIPS admittedly, have a GP register as
part of the ABI. This will differ between the app and RedBoot in memory
and is used as a base register for various memory accesses. So it needs to
be saved and later restored on entering and exiting redboot (or GDB stub
or whatever monitor) on entry and exit of a virtual vector handler.
Jifl
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