(+ Charles, Leif)

On 29 August 2016 at 08:45, Heyi Guo <heyi.guo@linaro.org> wrote:

Hi folks,

I have some questions about ARM SBSA v3.0 and SBBR v1.0. Could anyone please provide the answers or some ideas?

1. In SBSA it says that I/O virtualization property should be expressed by system firmware data. Then how to express this information by ACPI? Is only IORT table related? Or is there any examples?

2. In SBSA Section 4.1.3, page 14 as below, does the term "memory" here also include peripheral memory mapped IO spaces? Does the term "access" include both "read" and "write"? If write is also included, I'm afraid there might be some critical configuration registers which will cause unpredicted behavior or even system hang due to unintended random write.

'

​Populated or not' means it could be memory, MMIO or nothing at all.

If a write to a system register causes a deadlock as a side effect, that is fine. This section simply stipulates that the write *itself* should complete in finite time.

​

3. In SBBR, EFI_LOAD_FILE2_PROTOCOL is a required protocol. However,it is not used for boot in UEFI, and is mainly used for loading PCIe option ROM in EDK2 implementation. So why is this protocol required while PCIe is not mandatory for ARM server?

​My guess is that this is an oversight. ​If PCIe is not mandatory, then this protocol should not be mandatory either.

4. In SBBR, for IPv6 related protocols, it is said that they are optional on platforms that do not support networking. The question is, on platforms that *do* support networking, do IPv6 protocols become mandatory? Or is it allowed for only supporting IPv4 protocols?

​Charles, Leif?​