“Persistent”-> EfiPersistentMemory (14)
“Reserved” -> EfiReservedMemoryType(0)
On Thursday, July 20, 2017 10:56 AM, Soccer Liu <soccer_liu(a)yahoo.com> wrote:
I am sorry for not being more clear.
In ACPI spec 2.6, the Table 15-317 has all the UEFI Memory Types and mapping to ACPI
address range types.
Here are the actual types that I referred to:
“Persistent”-> EfiPersistentMemory (14)“Reserved” -> Reserved type 15
Apparently, only my private kernel works as expected when dealing with Reserved type (15)
but cannot boot with any EfiPersistentMemory device. I did see a EfiPersistentMemory
device working with Ubuntu OS. I am suspecting it's my environment issues (kconfig
flags or others), I am curious about anyone has any idea on how to debug this kind of
"does not boot issue" or anyone has seen EfiPersistentMemory like this?
On Thursday, July 20, 2017 6:03 AM, Dan Williams <dan.j.williams(a)intel.com>
On Wed, Jul 19, 2017 at 5:04 PM, Soccer Liu <soccer_liu(a)yahoo.com> wrote:
I am trying to debug an issue related to my private built kernel's (4.11 from
upstream with ACPI/NFIT/NVDIMM enabled) interaction with a persistent memory device's
We have a way to emulate a software based NVDIMM device into a guest, which is running my
private built kernel. When the host set this emulated NVDIMM device as Reserved type, I
was able to see a pmem0 block device exposed and everything seems to function
correctly.however, when it's exposed as a Persistent Memory type, the kernel does not
boot and it has a black screen and no usefully logging could help root cause this.
My questions are:
1. Is this a known issue for 4.11? 2. Is there any patches NIFT/NVDIMM beyond 4.11
that's needed to get Persistent Memory type supported? 3. In this case, is there
anyway to debug this further?
When you say Persistent Memory Type, which type are you referring. The
spec compliant one is E820-type-7 or EFI- type-15. Linux also
understands E820-type-12 which went upstream before the official types
E820-Type-12 is the problematic one, the others are equivalent to
All that said we have had functional support for all these types since
the 4.2 kernel, no kernel changes should be needed.
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