On Tue, Jul 20, 2021 at 12:33:14PM -0600, Simon Glass wrote:
Hi Tom.
On Tue, 20 Jul 2021 at 10:05, Tom Rini trini@konsulko.com wrote:
On Tue, Jul 20, 2021 at 09:57:55AM -0600, Simon Glass wrote:
Hi Tom,
On Tue, 20 Jul 2021 at 08:22, Tom Rini trini@konsulko.com wrote:
On Tue, Jul 20, 2021 at 07:29:24AM -0600, Simon Glass wrote:
U-Boot mostly uses hex for value input, largely because addresses are much easier to understand in hex.
But in some cases a hex value is requested, but it is more convenient to provide a decimal value. This may be because the value comes from another source, where its base cannot be controlled.
This series adds support for a 0m prefix to indicate a decimal number. The
I _really_ don't want to invent something here. When the setexpr thread came up before I went and did a little digging. Per https://en.wikipedia.org/wiki/Radix the general way to express a number is (x)y where x is the number and y is the base (and y is in base10, and also a subscript). I thought it was a bit cumbersome for general use and didn't bring it up at the time.
Well I don't want to invent something either...but what to do?
So for example (10)123 would mean decimal 123? I don't know how we would parse brackets separately from expressions though.
(123)10 would be "123" in decimal. Which is indeed a mouthful. But it would also be generic and (123)16 would be 0x123. So the parsing shouldn't be too hard, for most commands. But then yes, expressions become quite hard.
If we're going to add some global way to always say a number is decimal, and I'm not sure I think that's a good idea even (I kind of think it might be better on a case by case basis to maybe tweak some prints so that for example "ls mmc 0:10" tells the user it's accessing partition 16 would lead to a quick "oh that's hex, #$%@!"), I think it should follow the radix notation, or if not, some other well known example.
Can you give examples for what you are thinking for radix notation?
Well, since we don't have subscript in shell, '(number)base' would how it would be. Which I'm not convinced is better than making it clear to users that almost everything is hex input, including a few places that might surprise you such as partition numbers.
After a bit of thought and digging, I think that is a mathematical thing and confusing/unworkable on the command line.
I agree.
Should we consider 0t for decimal?
My biggest concern is that when I search for "0t prefix" the first relevant answers are the MS links where 0t is for ocTal, and not the other examples where it's decimal (base Ten, I assume).