* Re: Linux on sparc v7
2012-05-21 14:14 Linux on sparc v7 Daniel Hellstrom
@ 2012-05-21 16:16 ` Sam Ravnborg
2012-05-22 6:28 ` Daniel Hellstrom
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Sam Ravnborg @ 2012-05-21 16:16 UTC (permalink / raw)
To: sparclinux
On Mon, May 21, 2012 at 04:14:20PM +0200, Daniel Hellstrom wrote:
> Hello Dave,
>
> I am trying to catch up on what has been happening lately with the sparc
> port. Have the latest patches removed support for SPARC V7 CPUs?
Yes. The sun4c were the only users of v7 so today we tell gcc to generate v8
code. This imply support for muldiv & friends.
From the sparc Makefile:
KBUILD_CFLAGS += -mcpu=v8
As a side-note - we require support for the "flush" instruction now.
I assume LEON support this.
> The LEON VHDL model supports both V7 and V8 CPUs,
> FPU and non-FPU in any combination.
I do not have any overview on the FPU side of things.
Sam
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: Linux on sparc v7
2012-05-21 14:14 Linux on sparc v7 Daniel Hellstrom
2012-05-21 16:16 ` Sam Ravnborg
@ 2012-05-22 6:28 ` Daniel Hellstrom
2012-05-22 6:31 ` Julian Calaby
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Daniel Hellstrom @ 2012-05-22 6:28 UTC (permalink / raw)
To: sparclinux
On 05/21/2012 06:16 PM, Sam Ravnborg wrote:
> On Mon, May 21, 2012 at 04:14:20PM +0200, Daniel Hellstrom wrote:
>> Hello Dave,
>>
>> I am trying to catch up on what has been happening lately with the sparc
>> port. Have the latest patches removed support for SPARC V7 CPUs?
> Yes. The sun4c were the only users of v7 so today we tell gcc to generate v8
> code. This imply support for muldiv& friends.
>
> > From the sparc Makefile:
>
> KBUILD_CFLAGS += -mcpu=v8
Does this mean that if we change it to mcpu=v7 or mcpu=cypress (or removing mcpu=v8) the kernel can still be run on a V7 CPU? Or have software routines for making V8 mul/div operations on a V7 CPU
been removed so that V7 CPUs can't run Linux regardless of compiler option?
> As a side-note - we require support for the "flush" instruction now.
> I assume LEON support this.
Yes, flush invalidates all of the instruction cache.
>> The LEON VHDL model supports both V7 and V8 CPUs,
>> FPU and non-FPU in any combination.
> I do not have any overview on the FPU side of things.
Thanks,
Daniel
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: Linux on sparc v7
2012-05-21 14:14 Linux on sparc v7 Daniel Hellstrom
2012-05-21 16:16 ` Sam Ravnborg
2012-05-22 6:28 ` Daniel Hellstrom
@ 2012-05-22 6:31 ` Julian Calaby
2012-05-22 15:20 ` David Miller
2012-05-23 12:27 ` Daniel Hellstrom
4 siblings, 0 replies; 6+ messages in thread
From: Julian Calaby @ 2012-05-22 6:31 UTC (permalink / raw)
To: sparclinux
Hi,
On Tue, May 22, 2012 at 4:28 PM, Daniel Hellstrom <daniel@gaisler.com> wrote:
> On 05/21/2012 06:16 PM, Sam Ravnborg wrote:
>>
>> On Mon, May 21, 2012 at 04:14:20PM +0200, Daniel Hellstrom wrote:
>>>
>>> Hello Dave,
>>>
>>> I am trying to catch up on what has been happening lately with the sparc
>>> port. Have the latest patches removed support for SPARC V7 CPUs?
>>
>> Yes. The sun4c were the only users of v7 so today we tell gcc to generate
>> v8
>> code. This imply support for muldiv& friends.
>>
>>
>> > From the sparc Makefile:
>>
>> KBUILD_CFLAGS += -mcpu=v8
>
>
> Does this mean that if we change it to mcpu=v7 or mcpu=cypress (or removing
> mcpu=v8) the kernel can still be run on a V7 CPU? Or have software routines
> for making V8 mul/div operations on a V7 CPU been removed so that V7 CPUs
> can't run Linux regardless of compiler option?
As I understand it, all support for v7 CPUs, including the mul/div
routines has been annihilated.
So from 3.5 onwards, Linux required a v8 CPU or newer.
Thanks,
--
Julian Calaby
Email: julian.calaby@gmail.com
Profile: http://www.google.com/profiles/julian.calaby/
.Plan: http://sites.google.com/site/juliancalaby/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Linux on sparc v7
2012-05-21 14:14 Linux on sparc v7 Daniel Hellstrom
` (2 preceding siblings ...)
2012-05-22 6:31 ` Julian Calaby
@ 2012-05-22 15:20 ` David Miller
2012-05-23 12:27 ` Daniel Hellstrom
4 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2012-05-22 15:20 UTC (permalink / raw)
To: sparclinux
From: Daniel Hellstrom <daniel@gaisler.com>
Date: Tue, 22 May 2012 08:28:24 +0200
> On 05/21/2012 06:16 PM, Sam Ravnborg wrote:
>> On Mon, May 21, 2012 at 04:14:20PM +0200, Daniel Hellstrom wrote:
>>> Hello Dave,
>>>
>>> I am trying to catch up on what has been happening lately with the
>>> sparc
>>> port. Have the latest patches removed support for SPARC V7 CPUs?
>> Yes. The sun4c were the only users of v7 so today we tell gcc to
>> generate v8
>> code. This imply support for muldiv& friends.
>>
>> > From the sparc Makefile:
>>
>> KBUILD_CFLAGS += -mcpu=v8
>
> Does this mean that if we change it to mcpu=v7 or mcpu=cypress (or
> removing mcpu=v8) the kernel can still be run on a V7 CPU? Or have
> software routines for making V8 mul/div operations on a V7 CPU been
> removed so that V7 CPUs can't run Linux regardless of compiler option?
The kernel will never run on a v7 cpu ever again, as we've removed
support for the sun4c architecture completely.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: Linux on sparc v7
2012-05-21 14:14 Linux on sparc v7 Daniel Hellstrom
` (3 preceding siblings ...)
2012-05-22 15:20 ` David Miller
@ 2012-05-23 12:27 ` Daniel Hellstrom
4 siblings, 0 replies; 6+ messages in thread
From: Daniel Hellstrom @ 2012-05-23 12:27 UTC (permalink / raw)
To: sparclinux
On 05/22/2012 08:28 AM, Daniel Hellstrom wrote:
> On 05/21/2012 06:16 PM, Sam Ravnborg wrote:
>> On Mon, May 21, 2012 at 04:14:20PM +0200, Daniel Hellstrom wrote:
>>> Hello Dave,
>>>
>>> I am trying to catch up on what has been happening lately with the sparc
>>> port. Have the latest patches removed support for SPARC V7 CPUs?
>> Yes. The sun4c were the only users of v7 so today we tell gcc to generate v8
>> code. This imply support for muldiv& friends.
>>
>> > From the sparc Makefile:
>>
>> KBUILD_CFLAGS += -mcpu=v8
>
> Does this mean that if we change it to mcpu=v7 or mcpu=cypress (or removing mcpu=v8) the kernel can still be run on a V7 CPU? Or have software routines for making V8 mul/div operations on a V7 CPU
> been removed so that V7 CPUs can't run Linux regardless of compiler option?
>
>> As a side-note - we require support for the "flush" instruction now.
>> I assume LEON support this.
> Yes, flush invalidates all of the instruction cache.
Note that it will also flush the LEON data cache. Flushing on a LEON is normally done:
* I-cache, write anywhere using ASI=0x15
* D-cache, write anywhere using ASI=0x16
Daniel
>
>>> The LEON VHDL model supports both V7 and V8 CPUs,
>>> FPU and non-FPU in any combination.
>> I do not have any overview on the FPU side of things.
> Thanks,
> Daniel
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^ permalink raw reply [flat|nested] 6+ messages in thread