diff mbox series

[RFC] docs: add some notes on the sbsa-ref machine

Message ID 20201103104710.27150-1-alex.bennee@linaro.org
State New
Headers show
Series [RFC] docs: add some notes on the sbsa-ref machine | expand

Commit Message

Alex Bennée Nov. 3, 2020, 10:47 a.m. UTC
We should at least document what this machine is about.

Cc: Graeme Gregory <graeme@nuviainc.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Hongbo Zhang <hongbo.zhang@linaro.org>
Cc: Shashi Mallela <shashi.mallela@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 docs/system/arm/sbsa.rst   | 30 ++++++++++++++++++++++++++++++
 docs/system/target-arm.rst |  1 +
 2 files changed, 31 insertions(+)
 create mode 100644 docs/system/arm/sbsa.rst

Comments

Graeme Gregory Nov. 3, 2020, 10:57 a.m. UTC | #1
On Tue, Nov 03, 2020 at 10:47:10AM +0000, Alex Bennée wrote:
> We should at least document what this machine is about.

> 

Looks good to me.

Reviewed-by: Graeme Gregory <graeme@nuviainc.com>


> Cc: Graeme Gregory <graeme@nuviainc.com>

> Cc: Leif Lindholm <leif@nuviainc.com>

> Cc: Hongbo Zhang <hongbo.zhang@linaro.org>

> Cc: Shashi Mallela <shashi.mallela@linaro.org>

> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

> ---

>  docs/system/arm/sbsa.rst   | 30 ++++++++++++++++++++++++++++++

>  docs/system/target-arm.rst |  1 +

>  2 files changed, 31 insertions(+)

>  create mode 100644 docs/system/arm/sbsa.rst

> 

> diff --git a/docs/system/arm/sbsa.rst b/docs/system/arm/sbsa.rst

> new file mode 100644

> index 0000000000..a47c9360de

> --- /dev/null

> +++ b/docs/system/arm/sbsa.rst

> @@ -0,0 +1,30 @@

> +Arm Server Base System Architecture Reference board (``sbsa-ref``)

> +==================================================================

> +

> +While the `virt` board is a generic board platform that doesn't match

> +any real hardware the `sbsa-ref` board intends to look like real

> +hardware. The `Server Base System Architecture

> +<https://developer.arm.com/documentation/den0029/latest>` defines a

> +minimum base line of hardware support and importantly how the firmware

> +reports that to any operating system. It is a static system that

> +reports a very minimal DT to the firmware for command line input to

> +the firmware. As a result it must have a firmware specifically built

> +to expect a certain hardware layout (as you would in a real machine).

> +

> +It is intended to be a machine for developing firmware and testing

> +standards compliance with operating systems.

> +

> +Supported devices

> +"""""""""""""""""

> +

> +The sbsa-ref board supports:

> +

> +  - A configurable number of Cortex-A57 cpus

> +  - GIC version 3

> +  - System bus AHCI controller.

> +  - System bus EHCI controller.

> +  - CDROM and hard disc on AHCI bus.

> +  - E1000E ethernet card on PCIE bus.

> +  - VGA display adaptor on PCIE bus.

> +  - A generic SBSA watchdog device

> +

> diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst

> index fdcf25c237..9636f3fd00 100644

> --- a/docs/system/target-arm.rst

> +++ b/docs/system/target-arm.rst

> @@ -79,6 +79,7 @@ undocumented; you can get a complete list by running

>     arm/mps2

>     arm/musca

>     arm/realview

> +   arm/sbsa-ref

>     arm/versatile

>     arm/vexpress

>     arm/aspeed

> -- 

> 2.20.1

>
Leif Lindholm Nov. 3, 2020, 11:23 a.m. UTC | #2
On Tue, Nov 03, 2020 at 10:47:10 +0000, Alex Bennée wrote:
> We should at least document what this machine is about.


Thanks!
(comments below)

> Cc: Graeme Gregory <graeme@nuviainc.com>

> Cc: Leif Lindholm <leif@nuviainc.com>

> Cc: Hongbo Zhang <hongbo.zhang@linaro.org>

> Cc: Shashi Mallela <shashi.mallela@linaro.org>

> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

> ---

>  docs/system/arm/sbsa.rst   | 30 ++++++++++++++++++++++++++++++

>  docs/system/target-arm.rst |  1 +

>  2 files changed, 31 insertions(+)

>  create mode 100644 docs/system/arm/sbsa.rst

> 

> diff --git a/docs/system/arm/sbsa.rst b/docs/system/arm/sbsa.rst

> new file mode 100644

> index 0000000000..a47c9360de

> --- /dev/null

> +++ b/docs/system/arm/sbsa.rst

> @@ -0,0 +1,30 @@

> +Arm Server Base System Architecture Reference board (``sbsa-ref``)

> +==================================================================

> +

> +While the `virt` board is a generic board platform that doesn't match

> +any real hardware the `sbsa-ref` board intends to look like real

> +hardware. The `Server Base System Architecture

> +<https://developer.arm.com/documentation/den0029/latest>` defines a

> +minimum base line of hardware support and importantly how the firmware

> +reports that to any operating system. It is a static system that

> +reports a very minimal DT to the firmware for command line input to

> +the firmware.


I think you mean the right thing, but ...
"a very minimal DT to the firmware for non-discoverable information
 about components affected by the qemu command line"
 (i.e. cpus and memory)

> As a result it must have a firmware specifically built

> +to expect a certain hardware layout (as you would in a real machine).

> +

> +It is intended to be a machine for developing firmware and testing

> +standards compliance with operating systems.

> +

> +Supported devices

> +"""""""""""""""""

> +

> +The sbsa-ref board supports:

> +

> +  - A configurable number of Cortex-A57 cpus

> +  - GIC version 3


The intent was always for sbsa-ref to be tracking SBSA development, so
I wonder whether we should be documenting specific versions of cpu and
gic (and then keep remembering to update the docs).
My short-term plan was to swap the a57 for "max", but
documentation-wise, could we just say "number of aarch64 cpus"?
Could we refer to the gic as "latest supported emulated"?

/
    Leif

> +  - System bus AHCI controller.

> +  - System bus EHCI controller.

> +  - CDROM and hard disc on AHCI bus.

> +  - E1000E ethernet card on PCIE bus.

> +  - VGA display adaptor on PCIE bus.

> +  - A generic SBSA watchdog device

> +

> diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst

> index fdcf25c237..9636f3fd00 100644

> --- a/docs/system/target-arm.rst

> +++ b/docs/system/target-arm.rst

> @@ -79,6 +79,7 @@ undocumented; you can get a complete list by running

>     arm/mps2

>     arm/musca

>     arm/realview

> +   arm/sbsa-ref

>     arm/versatile

>     arm/vexpress

>     arm/aspeed

> -- 

> 2.20.1

>
Peter Maydell Nov. 3, 2020, noon UTC | #3
On Tue, 3 Nov 2020 at 10:47, Alex Bennée <alex.bennee@linaro.org> wrote:
>

> We should at least document what this machine is about.


typo and grammar nits only:

> +Supported devices

> +"""""""""""""""""

> +

> +The sbsa-ref board supports:

> +

> +  - A configurable number of Cortex-A57 cpus


"CPUs"

(Also if you take Leif's suggestion, "AArch64" not "aarch64".)

> +  - GIC version 3

> +  - System bus AHCI controller.

> +  - System bus EHCI controller.


Can we be consistent about either ending with a full stop or not
in this list? I think the usual style is not to.

> +  - CDROM and hard disc on AHCI bus.

> +  - E1000E ethernet card on PCIE bus.

> +  - VGA display adaptor on PCIE bus.


"PCIe"

> +  - A generic SBSA watchdog device


thanks
-- PMM
Alex Bennée Nov. 4, 2020, 4:54 p.m. UTC | #4
Leif Lindholm <leif@nuviainc.com> writes:

> On Tue, Nov 03, 2020 at 10:47:10 +0000, Alex Bennée wrote:

>> We should at least document what this machine is about.

>

> Thanks!

> (comments below)

>

>> Cc: Graeme Gregory <graeme@nuviainc.com>

>> Cc: Leif Lindholm <leif@nuviainc.com>

>> Cc: Hongbo Zhang <hongbo.zhang@linaro.org>

>> Cc: Shashi Mallela <shashi.mallela@linaro.org>

>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

>> ---

>>  docs/system/arm/sbsa.rst   | 30 ++++++++++++++++++++++++++++++

>>  docs/system/target-arm.rst |  1 +

>>  2 files changed, 31 insertions(+)

>>  create mode 100644 docs/system/arm/sbsa.rst

>> 

>> diff --git a/docs/system/arm/sbsa.rst b/docs/system/arm/sbsa.rst

>> new file mode 100644

>> index 0000000000..a47c9360de

>> --- /dev/null

>> +++ b/docs/system/arm/sbsa.rst

>> @@ -0,0 +1,30 @@

>> +Arm Server Base System Architecture Reference board (``sbsa-ref``)

>> +==================================================================

>> +

>> +While the `virt` board is a generic board platform that doesn't match

>> +any real hardware the `sbsa-ref` board intends to look like real

>> +hardware. The `Server Base System Architecture

>> +<https://developer.arm.com/documentation/den0029/latest>` defines a

>> +minimum base line of hardware support and importantly how the firmware

>> +reports that to any operating system. It is a static system that

>> +reports a very minimal DT to the firmware for command line input to

>> +the firmware.

>

> I think you mean the right thing, but ...

> "a very minimal DT to the firmware for non-discoverable information

>  about components affected by the qemu command line"

>  (i.e. cpus and memory)

>

>> As a result it must have a firmware specifically built

>> +to expect a certain hardware layout (as you would in a real machine).

>> +

>> +It is intended to be a machine for developing firmware and testing

>> +standards compliance with operating systems.

>> +

>> +Supported devices

>> +"""""""""""""""""

>> +

>> +The sbsa-ref board supports:

>> +

>> +  - A configurable number of Cortex-A57 cpus

>> +  - GIC version 3

>

> The intent was always for sbsa-ref to be tracking SBSA development, so

> I wonder whether we should be documenting specific versions of cpu and

> gic (and then keep remembering to update the docs).

> My short-term plan was to swap the a57 for "max", but

> documentation-wise, could we just say "number of aarch64 cpus"?

> Could we refer to the gic as "latest supported emulated"?


I'm not sure we want a movable feast... shouldn't we at least provide
compatibility for older variations? -cpu max is useful but you can get
new features coming out of the blue.

-- 
Alex Bennée
diff mbox series

Patch

diff --git a/docs/system/arm/sbsa.rst b/docs/system/arm/sbsa.rst
new file mode 100644
index 0000000000..a47c9360de
--- /dev/null
+++ b/docs/system/arm/sbsa.rst
@@ -0,0 +1,30 @@ 
+Arm Server Base System Architecture Reference board (``sbsa-ref``)
+==================================================================
+
+While the `virt` board is a generic board platform that doesn't match
+any real hardware the `sbsa-ref` board intends to look like real
+hardware. The `Server Base System Architecture
+<https://developer.arm.com/documentation/den0029/latest>` defines a
+minimum base line of hardware support and importantly how the firmware
+reports that to any operating system. It is a static system that
+reports a very minimal DT to the firmware for command line input to
+the firmware. As a result it must have a firmware specifically built
+to expect a certain hardware layout (as you would in a real machine).
+
+It is intended to be a machine for developing firmware and testing
+standards compliance with operating systems.
+
+Supported devices
+"""""""""""""""""
+
+The sbsa-ref board supports:
+
+  - A configurable number of Cortex-A57 cpus
+  - GIC version 3
+  - System bus AHCI controller.
+  - System bus EHCI controller.
+  - CDROM and hard disc on AHCI bus.
+  - E1000E ethernet card on PCIE bus.
+  - VGA display adaptor on PCIE bus.
+  - A generic SBSA watchdog device
+
diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
index fdcf25c237..9636f3fd00 100644
--- a/docs/system/target-arm.rst
+++ b/docs/system/target-arm.rst
@@ -79,6 +79,7 @@  undocumented; you can get a complete list by running
    arm/mps2
    arm/musca
    arm/realview
+   arm/sbsa-ref
    arm/versatile
    arm/vexpress
    arm/aspeed