* Only 3.5 GB RAM on Jetson TX1
@ 2017-03-23 0:13 Martin Michlmayr
[not found] ` <20170323001357.GA7546-IRMp5PtgtdoigzW5ZibpNwC/G2K4zDHf@public.gmane.org>
0 siblings, 1 reply; 5+ messages in thread
From: Martin Michlmayr @ 2017-03-23 0:13 UTC (permalink / raw)
To: linux-tegra-u79uwXL29TY76Z2rM5mHXA; +Cc: Vagrant Cascadian
Vagrant Cascadian observed that only 3.5 GB RAM are available on the
Jetson TX1 development kit.
[ 0.000000] Memory: 3501036K/3670016K available (6780K kernel code, 1020K rwdata, 2164K rodata, 3264K init, 634K bss, 168980K reserved, 0K cma-reserved)
Interestingly, even u-boot only shows 3.5 GB:
DRAM: 3.5 GiB
This is with mainline u-boot 2016.11 and R23.2 (2016.03-00633-g3ef9cdb).
However, 2015.07-rc2-g78c8468 (from R23.1.1) shows:
DRAM: 4 GiB
but that u-boot doesn't boot mainline kernels (some DT errors).
--
Martin Michlmayr
http://www.cyrius.com/
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Only 3.5 GB RAM on Jetson TX1
[not found] ` <20170323001357.GA7546-IRMp5PtgtdoigzW5ZibpNwC/G2K4zDHf@public.gmane.org>
@ 2017-03-23 16:24 ` Stephen Warren
[not found] ` <8453cf91-0b27-9968-59b8-7b697e8cd1f8-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
0 siblings, 1 reply; 5+ messages in thread
From: Stephen Warren @ 2017-03-23 16:24 UTC (permalink / raw)
To: Martin Michlmayr
Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA, Vagrant Cascadian, Tom Warren
On 03/22/2017 06:13 PM, Martin Michlmayr wrote:
> Vagrant Cascadian observed that only 3.5 GB RAM are available on the
> Jetson TX1 development kit.
>
> [ 0.000000] Memory: 3501036K/3670016K available (6780K kernel code, 1020K rwdata, 2164K rodata, 3264K init, 634K bss, 168980K reserved, 0K cma-reserved)
>
> Interestingly, even u-boot only shows 3.5 GB:
>
> DRAM: 3.5 GiB
>
> This is with mainline u-boot 2016.11 and R23.2 (2016.03-00633-g3ef9cdb).
That's expected.
A portion of the top-of-ram holds various carve-outs, such as for the
secure OS and perhaps other purposes like media buffers. Mainline U-Boot
currently hard-codes the size of this unusable RAM area to a very
conservative size. Ideally, U-Boot would query the size of the RAM from
the secure monitor, or retrieve it from information passed by an earlier
stage bootloader. However, doing so relies on using interfaces that may
not be strict ABIs, so we didn't want to make upstream U-Boot use them
at least when we first upstreamed T210 support.
> However, 2015.07-rc2-g78c8468 (from R23.1.1) shows:
>
> DRAM: 4 GiB
>
> but that u-boot doesn't boot mainline kernels (some DT errors).
Conversely, the L4T version of U-Boot is expected to work with the
specific SW stack shipped with L4T, and hence does determine the
carveout size at runtime, and hence allows access to a bit more RAM.
L4T U-Boot should boot an upstream kernel without issue. You may need to
delete a few environment variables to stop U-Boot attempting to copy
some data from the NV-bootloader-supplied DTB into the DTB that U-Boot
itself loads from "disk" and passes to the kernel.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Only 3.5 GB RAM on Jetson TX1
[not found] ` <8453cf91-0b27-9968-59b8-7b697e8cd1f8-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
@ 2017-03-23 16:33 ` Stephen Warren
2017-03-24 19:55 ` Ralf Ramsauer
1 sibling, 0 replies; 5+ messages in thread
From: Stephen Warren @ 2017-03-23 16:33 UTC (permalink / raw)
To: Martin Michlmayr
Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA, Vagrant Cascadian, Tom Warren
On 03/23/2017 10:24 AM, Stephen Warren wrote:
> On 03/22/2017 06:13 PM, Martin Michlmayr wrote:
>> Vagrant Cascadian observed that only 3.5 GB RAM are available on the
>> Jetson TX1 development kit.
>>
>> [ 0.000000] Memory: 3501036K/3670016K available (6780K kernel code,
>> 1020K rwdata, 2164K rodata, 3264K init, 634K bss, 168980K reserved, 0K
>> cma-reserved)
>>
>> Interestingly, even u-boot only shows 3.5 GB:
>>
>> DRAM: 3.5 GiB
>>
>> This is with mainline u-boot 2016.11 and R23.2 (2016.03-00633-g3ef9cdb).
>
> That's expected.
>
> A portion of the top-of-ram holds various carve-outs, such as for the
> secure OS and perhaps other purposes like media buffers. Mainline U-Boot
> currently hard-codes the size of this unusable RAM area to a very
> conservative size. Ideally, U-Boot would query the size of the RAM from
> the secure monitor, or retrieve it from information passed by an earlier
> stage bootloader. However, doing so relies on using interfaces that may
> not be strict ABIs, so we didn't want to make upstream U-Boot use them
> at least when we first upstreamed T210 support.
>
>> However, 2015.07-rc2-g78c8468 (from R23.1.1) shows:
>>
>> DRAM: 4 GiB
>>
>> but that u-boot doesn't boot mainline kernels (some DT errors).
>
> Conversely, the L4T version of U-Boot is expected to work with the
> specific SW stack shipped with L4T, and hence does determine the
> carveout size at runtime, and hence allows access to a bit more RAM.
>
> L4T U-Boot should boot an upstream kernel without issue. You may need to
> delete a few environment variables to stop U-Boot attempting to copy
> some data from the NV-bootloader-supplied DTB into the DTB that U-Boot
> itself loads from "disk" and passes to the kernel.
In particular, I'd expect clearing the following variables to solve any
DT related errors:
fdt_copy_node_paths
fdt_del_prop_paths
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Only 3.5 GB RAM on Jetson TX1
[not found] ` <8453cf91-0b27-9968-59b8-7b697e8cd1f8-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2017-03-23 16:33 ` Stephen Warren
@ 2017-03-24 19:55 ` Ralf Ramsauer
[not found] ` <b61c05f6-a088-a2c1-b512-fc7b3fca618e-ex4EvEgDZR1o7HI0AxOeTKwczVv4G7md@public.gmane.org>
1 sibling, 1 reply; 5+ messages in thread
From: Ralf Ramsauer @ 2017-03-24 19:55 UTC (permalink / raw)
To: Stephen Warren, Martin Michlmayr
Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA, Vagrant Cascadian,
Tom Warren, Claudio Scordino
Hi,
On 03/23/2017 05:24 PM, Stephen Warren wrote:
> On 03/22/2017 06:13 PM, Martin Michlmayr wrote:
>> Vagrant Cascadian observed that only 3.5 GB RAM are available on the
>> Jetson TX1 development kit.
>>
>> [ 0.000000] Memory: 3501036K/3670016K available (6780K kernel code,
>> 1020K rwdata, 2164K rodata, 3264K init, 634K bss, 168980K reserved, 0K
>> cma-reserved)
>>
>> Interestingly, even u-boot only shows 3.5 GB:
>>
>> DRAM: 3.5 GiB
>>
>> This is with mainline u-boot 2016.11 and R23.2 (2016.03-00633-g3ef9cdb).
>
> That's expected.
>
> A portion of the top-of-ram holds various carve-outs, such as for the
> secure OS and perhaps other purposes like media buffers. Mainline U-Boot
> currently hard-codes the size of this unusable RAM area to a very
> conservative size. Ideally, U-Boot would query the size of the RAM from
> the secure monitor, or retrieve it from information passed by an earlier
> stage bootloader. However, doing so relies on using interfaces that may
> not be strict ABIs, so we didn't want to make upstream U-Boot use them
> at least when we first upstreamed T210 support.
So is it just a pessimistic carve-out that not only affect the TX1, or
does the TX1 really have a secure monitor?
>
>> However, 2015.07-rc2-g78c8468 (from R23.1.1) shows:
>>
>> DRAM: 4 GiB
>>
>> but that u-boot doesn't boot mainline kernels (some DT errors).
>
> Conversely, the L4T version of U-Boot is expected to work with the
> specific SW stack shipped with L4T, and hence does determine the
> carveout size at runtime, and hence allows access to a bit more RAM.
I interpret this that *some* memory up there is in deed in use, no
matter if we use L4T or mainline Linux/U-Boot, right?
Thanks
Ralf
>
> L4T U-Boot should boot an upstream kernel without issue. You may need to
> delete a few environment variables to stop U-Boot attempting to copy
> some data from the NV-bootloader-supplied DTB into the DTB that U-Boot
> itself loads from "disk" and passes to the kernel.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-tegra" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Only 3.5 GB RAM on Jetson TX1
[not found] ` <b61c05f6-a088-a2c1-b512-fc7b3fca618e-ex4EvEgDZR1o7HI0AxOeTKwczVv4G7md@public.gmane.org>
@ 2017-03-24 20:12 ` Stephen Warren
0 siblings, 0 replies; 5+ messages in thread
From: Stephen Warren @ 2017-03-24 20:12 UTC (permalink / raw)
To: Ralf Ramsauer, Martin Michlmayr
Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA, Vagrant Cascadian,
Tom Warren, Claudio Scordino
On 03/24/2017 01:55 PM, Ralf Ramsauer wrote:
> Hi,
>
> On 03/23/2017 05:24 PM, Stephen Warren wrote:
>> On 03/22/2017 06:13 PM, Martin Michlmayr wrote:
>>> Vagrant Cascadian observed that only 3.5 GB RAM are available on the
>>> Jetson TX1 development kit.
>>>
>>> [ 0.000000] Memory: 3501036K/3670016K available (6780K kernel code,
>>> 1020K rwdata, 2164K rodata, 3264K init, 634K bss, 168980K reserved, 0K
>>> cma-reserved)
>>>
>>> Interestingly, even u-boot only shows 3.5 GB:
>>>
>>> DRAM: 3.5 GiB
>>>
>>> This is with mainline u-boot 2016.11 and R23.2 (2016.03-00633-g3ef9cdb).
>>
>> That's expected.
>>
>> A portion of the top-of-ram holds various carve-outs, such as for the
>> secure OS and perhaps other purposes like media buffers. Mainline U-Boot
>> currently hard-codes the size of this unusable RAM area to a very
>> conservative size. Ideally, U-Boot would query the size of the RAM from
>> the secure monitor, or retrieve it from information passed by an earlier
>> stage bootloader. However, doing so relies on using interfaces that may
>> not be strict ABIs, so we didn't want to make upstream U-Boot use them
>> at least when we first upstreamed T210 support.
>
> So is it just a pessimistic carve-out that not only affect the TX1, or
> does the TX1 really have a secure monitor?
There's definitely a secure monitor running. There could be a secure OS
running, although L4T doesn't install one.
>>> However, 2015.07-rc2-g78c8468 (from R23.1.1) shows:
>>>
>>> DRAM: 4 GiB
>>>
>>> but that u-boot doesn't boot mainline kernels (some DT errors).
>>
>> Conversely, the L4T version of U-Boot is expected to work with the
>> specific SW stack shipped with L4T, and hence does determine the
>> carveout size at runtime, and hence allows access to a bit more RAM.
>
> I interpret this that *some* memory up there is in deed in use, no
> matter if we use L4T or mainline Linux/U-Boot, right?
Yes.
>
> Thanks
> Ralf
>>
>> L4T U-Boot should boot an upstream kernel without issue. You may need to
>> delete a few environment variables to stop U-Boot attempting to copy
>> some data from the NV-bootloader-supplied DTB into the DTB that U-Boot
>> itself loads from "disk" and passes to the kernel.
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-tegra" in
>> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-03-23 0:13 Only 3.5 GB RAM on Jetson TX1 Martin Michlmayr
[not found] ` <20170323001357.GA7546-IRMp5PtgtdoigzW5ZibpNwC/G2K4zDHf@public.gmane.org>
2017-03-23 16:24 ` Stephen Warren
[not found] ` <8453cf91-0b27-9968-59b8-7b697e8cd1f8-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2017-03-23 16:33 ` Stephen Warren
2017-03-24 19:55 ` Ralf Ramsauer
[not found] ` <b61c05f6-a088-a2c1-b512-fc7b3fca618e-ex4EvEgDZR1o7HI0AxOeTKwczVv4G7md@public.gmane.org>
2017-03-24 20:12 ` Stephen Warren
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