From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-x232.google.com (mail-io0-x232.google.com [IPv6:2607:f8b0:4001:c06::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 774BB1A1E0B for ; Tue, 27 Sep 2016 04:52:06 -0700 (PDT) Received: by mail-io0-x232.google.com with SMTP id 92so11938051iol.2 for ; Tue, 27 Sep 2016 04:52:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=bH2dVrF0Mvfg34E/MNY0OV1IiYcZ2vHv2h1kh/6IHYs=; b=fK7uhoHt9fr0coYZNC7Of1SHWyOZ6a1UbUOeyDIuWR7TrC3h1CzPqtSG0s7k/PURLa czrpmvI9NEe+pyz/kN3of8SEGT/gQBp+d4Pak1gZmkcUaZwQWIxOY6DU0JKghA3OP/5B wbggX2PuULqfczA2eyRgX1OdknVdA3lfSuR1TSPtYsbZEL/CDwOHBGmw9S+uSgVAQa4X ksVu3HA7gGoumfdfL/9rqzlq9B0PEbHqD+HrzcE3WWlBGxaeiRSLfnqKOJJKnwy2jVkx X+9HKViZ+UB404R34euwHW7MonKsG+1kx9tnzdHvIXTXUd1GnHe5TQrhZty/FGYxxrnW yuxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=bH2dVrF0Mvfg34E/MNY0OV1IiYcZ2vHv2h1kh/6IHYs=; b=CIKf5RftlTPrV30m1MTL8F+JEhIYLCbXskwuIYyhVsyW0Nb8RyhCgoFDt2HIC4b0U2 ZDu7mJGVarz3VncQmgjQ+3lmhaL/nPEkEb8KAT7h5FIAeQX1UCZsCbUBOFyfazoD0Ybs D4roKQyfU2Wh8iVcrWGWV6vVvzK0AXoE6mANzrPJoy1m1zKQfMb5XPXbi/5LwXwn1xws H/cbtSmIjgdGDi0bgEqLeIxnlLyS8lSyzC2xe/fHSyecYBfL1w59uam3s7JfmwCEYcvL swzPXg45cImP05QpyYylZgFYAe7UOr7UKG/mqXLKR1aia07dJnEAt1KP/RAyp3bED8kd MARg== X-Gm-Message-State: AE9vXwP1eU+/AtFDY1Kzn9CTQS2fajQAjvex4LULB8/H6vWI4Vv6/q99kJ16gg7oi86+T7bvatcmp+Lp81P/Kg== X-Received: by 10.107.168.225 with SMTP id e94mr32183026ioj.111.1474977125421; Tue, 27 Sep 2016 04:52:05 -0700 (PDT) MIME-Version: 1.0 References: <765021a6-cea7-ba5f-58cf-5e8fce05bbf2@redhat.com> <87d54199-6065-47e4-b3f8-04fd6f93220f@redhat.com> In-Reply-To: <87d54199-6065-47e4-b3f8-04fd6f93220f@redhat.com> From: GN Keshava Date: Tue, 27 Sep 2016 11:51:54 +0000 Message-ID: To: Laszlo Ersek Cc: "edk2-devel@lists.01.org" X-Content-Filtered-By: Mailman/MimeDel 2.1.21 Subject: Re: How to open a file by it's full path in UEFI X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Sep 2016 11:52:06 -0000 Content-Type: text/plain; charset=UTF-8 Thank you Laszlo. I'll check it out. :) Thanks again. Regards, Keshava On Tue, 27 Sep 2016 at 16:47 Laszlo Ersek wrote: > On 09/27/16 12:46, GN Keshava wrote: > > Hi Laszlo, > > > > Thank you for the answer. It was helpful. > > > > Considering option #1, can you give some more details (a small example > > or any reference link would be helpful), how I can use Shell APIs in my > > C file (which will compile to my .efi app)? > > Hmmm, I don't have hands-on experience with this, but you might want to > try the ShellOpenFileByName() function, from > "ShellPkg/Include/Library/ShellLib.h". > > You can find examples for UEFI applications that use the Shell library > with: > > git grep -w ShellLib -- '*inf' > > or just grep the tree for ShellOpenFileByName(). > > See also "AppPkg/ReadMe.txt". > > > Considering option #2, How I can find device path programatically from > > my C file? > > The EFI_SHELL_PROTOCOL.GetDevicePathFromMap() member function seems > relevant -- it is specified in the UEFI Shell spec --, but I would > definitely try ShellOpenFileByName() first. > > Thanks > Laszlo > > > Thanks again for the help. :) > > With regards, > > Keshava > > > > On Tue, 27 Sep 2016 at 15:19 Laszlo Ersek > > wrote: > > > > On 09/27/16 11:25, GN Keshava wrote: > > > Hi Laszlo, > > > > > > Thanks for the reply. I meant I have complete file path. I believe > the > > > "device path" is different. Is it possible to obtain DevicePath > > using my > > > full file path? > > > > The pathname you seem to have (as "complete") is specific to a given > > simple FS, so system-wide it cannot be considered complete (there > can be > > multiple filesystems). > > > > In your original email I missed that you started with "FS1:". > Andrew's > > answer covers that case. > > > > In summary, you can do three things: > > - have a pathname that starts with FSx: (which is a shell-specific > > mapping), and use Andrew's recommendation, > > - have a complete UEFI device path, and then use what I recommended, > > - have no information for selecting the filesystem (from the many > > possible), and use your current iteration. > > > > Options #1 and #2 actually correspond to each other, considering > > "expressive power" / information content (as long as you are in the > > shell); please see the MAP shell command. > > > > Thanks > > Laszlo > > > > > On Tue, 27 Sep 2016 at 14:46 Laszlo Ersek > > > > >> wrote: > > > > > > On 09/27/16 11:03, GN Keshava wrote: > > > > Hi all, > > > > > > > > > > > > I'm trying to open a file from my UEFI application. The path > of > > > file is > > > > > > > > fs1:/myfolder/myfile.txt > > > > > > > > The code : > > > > > > > > efiStatus = bs->LocateHandleBuffer(ByProtocol, > > > > &sfspGuid, > > > > NULL, > > > > &handleCount, > > > > &handles); > > > > > > > > for (index = 0; index < (int)handleCount; ++ index) > > > > { > > > > EFI_SIMPLE_FILE_SYSTEM_PROTOCOL* fs = NULL; > > > > > > > > efiStatus = bs->HandleProtocol( > > > > handles[index], > > > > &sfspGuid, > > > > (void**)&fs); > > > > > > > > EFI_FILE_PROTOCOL* root = NULL; > > > > ... > > > > efiStatus = fs->OpenVolume(fs, &root); > > > > > > > > EFI_FILE_PROTOCOL* token = NULL; > > > > > > > > efiStatus = root->Open( > > > > root, > > > > &token, > > > > L"myfolder\\myfile.txt", > > > > EFI_FILE_MODE_READ, > > > > EFI_FILE_READ_ONLY | EFI_FILE_HIDDEN | > EFI_FILE_SYSTEM); > > > > } > > > > > > > > But using this method, I can only go through all the file > system > > > handles > > > > and open each volume and try opening my file. > > > > > > > > But I want to give full path to my file and open it in it's > > volume. > > > > > > > > How can I acheive this? > > > > Thanks. > > > > > > If you have a complete device path, you can use > > gBS->LocateDevicePath() > > > with gEfiSimpleFileSystemProtocolGuid, to locate the handle > > with the > > > most specific device path (--> the longest device path prefix) > > with the > > > simple FS protocol installed on it. Then you can check if the > > remaining > > > device path (returned by the service) consist of nothing but > > one File > > > Path Media Device Path node. If so, you can open the simple FS > > protocol > > > on the handle found, then use that to open the file by > pathname. > > > > > > Laszlo > > > > > > >