Thank you for detailed answer. Laszlo. Regards, Keshava
On Thu, 29 Sep 2016 at 13:01 Laszlo Ersek <[email protected]> wrote: > CC Jaben > > On 09/29/16 08:01, GN Keshava wrote: > > Hi, > > > > There is fprintf function in Stdio library. But how to use it? The first > > argument is "FILE" type. But I have "EFI_FILE_PROTOCOL* File" which I got > > from "EFIOpenFile" function. How to map to "FILE" type? > > > > Sorry if this is silly. A newbie here. Didn't get much idea in internet > > search. :) > > (1) You're trying to mix edk2 APIs with standard C library APIs. Don't > do that. > > I think what you are missing is the fact that using edk2, you can write > a UEFI application *either* against edk2 APIs (protocols and libraries), > *or* against standard C APIs (using the stdlib implementation of edk2). > In some cases it is okay to call edk2 APIs directly, from stdlib > applications, but in general I'd advise against that. > > I told you to read "AppPkg/ReadMe.txt"; that file explains what is > necessary for what "flavor" of UEFI application. It even mentions two > example programs, "Main" and "Hello", which don't do anything but > highlight the differences. > > For another (quite self-contained) example, > "AppPkg/Applications/OrderedCollectionTest" is an application that I > wrote myself; it uses fopen() and fprintf(). This is a unit tester for > an MdePkg library that I also wrote, so it actually exemplifies how you > can use both stdlib and an edk2 library, as long as they don't step on > each other's toes. > > (2) You can write formatted output to files using only edk2 APIs as > well, but for that, you first have to format the text into memory > buffers with PrintLib functions, then write the buffers to files with > the ShellLib APIs or with direct protocol calls. > > (3) The standard C lib implementation in edk2 is only available for use > by UEFI applications (no other module types; that is, no drivers). > What's more, those applications have to be started from the shell (you > can't boot them directly from the boot manager, for example). This is > also documented in AppPkg/ReadMe.txt. > > Thanks > Laszlo > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
