Eric -
For #1, this seems like a VFR compiler error, since the Form Browser does not
place the container value in each element of the array (if the array is UINT16)
For #2, please refer to section 29.2.5.4.8, where it says:
"Storage The set questions are stored as a Buffer with one byte for each
Container."
Then also see 29.2.5.4.1: "Question values are a data type listed in Section
29.2.5.7.4." For an ordered list, the value is a Buffer (not one byte in a
buffer) See also the Callback for CHANGING/CHANGED where the Ordered List value
should be a buffer. The defaults 29.2.5.8 says "Defaults are pre-defined
question values." Options say they "give ...description of a particular
question value" (29.2.5.5)
This means that the Value of the question is the entire buffer, not just one
byte.
Consider this case: I want to set the default boot order to 5,6,7,8,0,2,4. I
understand that it is useful to see the value as one byte, and this might work
best for one-of, but not for default. In any case, either the Form Browser
needs to be changed or the specification needs to be changed for the
ordered-list case.
Tim
From: Dong, Eric [mailto:eric.d...@intel.com]
Sent: Monday, August 25, 2014 2:40 PM
To: edk2-devel@lists.sourceforge.net
Subject: Re: [edk2] HII ORDERED_LIST support
Tim,
Add my comments below.
From: Tim Lewis [mailto:tim.le...@insyde.com]
Sent: Friday, August 22, 2014 12:40 AM
To: edk2-devel@lists.sourceforge.net<mailto:edk2-devel@lists.sourceforge.net>
Subject: [edk2] HII ORDERED_LIST support
In DriverSampleDxe, the boot order item is listed in storage as:
UINT16 BootOrder[8];
And here is the ordered list which manipulates this item:
orderedlist
varid = MyIfrNVData.BootOrder,
prompt = STRING_TOKEN(0x006D),
help = STRING_TOKEN(0x0059),
option text = STRING_TOKEN(0x006F), value = 2, flags =
RESET_REQUIRED;
option text = STRING_TOKEN(0x006E), value = 1, flags =
RESET_REQUIRED;
option text = STRING_TOKEN(0x0070), value = 3, flags =
RESET_REQUIRED;
suppressif ideqval MyIfrNVData.BootOrderLarge == 0;
option text = STRING_TOKEN(0x0071), value = 4, flags =
RESET_REQUIRED;
endif
endlist;
This leads to a number of questions:
1) The BootOrder is defined as UINT16, but the UEFI specification clearly
states that an orderedlist will work on a buffer with one byte per container.
(See 29.2.5.4.8 where it says, "The set questions are stored as a Buffer with
one byte for each Container."
[[[Eric]]] Truly spec has this description but vfrcompile and browser not do
this check, also current code may already has samples which already violate
this rule, so I need more discussion to provide a good proposal for this case.
[TIM] I am not worried about the actual struct members. BootOrder is 16 bytes
(8 x sizeof(UINT16). So that means that MaxContainers will be 16, right? The
VFR spec says: "NOTE: maxcontainers is optional, and the default value depends
on the variable size defined by varid in vfrQuestionHeader" So it seems that,
even though the code will work, using UINT8
BootOrder[16] would be easier to understand than UINT16 BootOrder[8]"
[[[Eric]]] Base on current implementation, the maxcontainer value is the array
size. So for "UINT16 BootOrder[8]", the maxcontainer = 8 and for "UINT8
BootOrder[16]", the maxcontainer = 16. I think we need to add check for the
code first, only support one byte for each container.
2) The option values are all integers. But the storage type of an ordered
list is a BUFFER. To me this implies (I haven't looked this up) that the value
an option is being used as the option for a single container. That makes sense,
but it is not the behavior described in the UEFI specification. Also, there
seems to be no way to create a value for a question of type buffer.
[[[Eric]]] no catch what's your mean is.
[TIM] For example, for "oneof" the value storage size is UINT8/UINT16/UINT32 or
UINT64. The value storage size for "checkbox" is BOOLEAN. But what is the value
storage size of "orderedlist" When I read the UEFI specification, the "value
storage size" of orderedlist is maxcontainers x sizeof(UINT8). So, if
maxcontainers is 16, then 16 bytes. BUT: the size of the value in an "option"
inside the "orderedlist" in these examples is sizeof(UINT8), not maxcontainers
x sizeof(UINT8).
According to the UEFI specification, as I read it today, the value in a
ONE_OF_OPTION is the value for the entire value storage, not just one byte of
the value storage. So every container in the ordered list value should be set
to 2 when the first "ONE_OF_OPTION" (in the example above) is selected by the
user.
[[[Eric]]] I can't find this information from the spec, which page in UEFI spec
2.4b describe it?
But I do not believe this is what the EDK2 Form browser does today. I believe
that it only changes a single container to the value 2 (not the whole buffer).
3) Likewise, there seems to be no way to provide a default for an ordered
list.
[[[Eric]]] yes, ordered list opcode just base on the current option order to
set the default value. For your above example, the default value is 2,1,3,4.
[TIM] If I put a "default = 2" in the example above, will it set one container
to "2" or all containers to "2" Again, this is a problem with the way the
specification describes values for ordered list opcodes. It is fairly clear
that the EDK2 form browser takes a different approach than the current
specification.
Here is an example display:
Boot Order: [boot order 1] [boot order 2][boot order 3][boot order 4][boot
order 5][boot order 6][boot order 7][boot order 8]
Each [boot order x] is a container. If the user goes to [boot order 2] and uses
one of the ONE_OF_OPTION pre-defined values, does it change only [boot order 2]
or all [boot order x]? Now, what does the UEFI specification say should happen?
[[[Eric]]] what's your mean of "uses one of the ONE_OF_OPTION pre-defined
values"? for ordered list opcode, we can only change the order of the options,
can't only select one option, I don't know your means about this sample?
Tim
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