On Sat, Feb 18, 2017 at 2:45 PM, Moritz Fischer <moritz.fisc...@ettus.com> wrote: > On Sat, Feb 18, 2017 at 02:10:43PM -0600, Alan Tull wrote: >> On Sat, Feb 18, 2017 at 6:45 AM, Nadathur, Sundar >> <sundar.nadat...@intel.com> wrote: >> >> > Hi all, >> > Interesting discussion. The discussion so far has brought out many >> > concerns such as OS independence. There is an existing format, well-known >> > to developers, with widespread support, and which is quite extensible: >> > Type-Length-Value triples. >> > >> > To elaborate, a TLV-based format has many advantages: >> > * It is highly extensible in many ways >> > -- You can express structures and arrays using TLVs. Our needs right >> > now may seem limited but requirements grow over time.
Device tree can express arrays. >> > -- The space of Type values can be decomposed into standard pre-defined >> > values that are in upstreamed code, and possibly experimental or >> > feature-specific values. >> > -- Forward compatibility: We can write parsers that can skip unexpected >> > type values, thus allowing old parsers to work with new additions. With >> > some tweaks, old parsers can also reject unexpected values in some ranges >> > while accepting them in other ranges. >> > * It is OS-independent. >> > * It can be easily parsed, in kernel or user space. > > Are there other users of the format? I have to admit I didn't look very > long, but couldn't find any libs / existing code at a first glance. Is there a standard you are looking at? Have you seen any use of TLV's in the Linux kernel you could point to? > >> > * It can be validated, in terms of Type values, acceptable lengths, etc. >> > >> > It is not directly human-readable but that can be easily addressed with a >> > tool that parses TLVs. >> > >> > Compared to some other proposals: >> > * Compared to DTs, TLVs are OS-independent. > > That's just alternative facts here. Just because Linux uses fdt for > devicetree blobs it is *not* OS dependent. There are several (see > last email) non-Linux users of fdt / libfdt. > > Thanks, > > Moritz It is worth repeating that libdtc is GPL/BSD with the intent of allowing proprietary code to use libdtc. So license shouldn't be a barrier. Using device tree in the header would give us a way of doing enumeration at least for Linux, not sure if that kind of info can be used in Windows in some way. Alan
