<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="ProgId" content="Word.Document"> <meta name="Generator" content="Microsoft Word 15"> <meta name="Originator" content="Microsoft Word 15"> <link rel="File-List" href="cid:filelist.xml@01D77E20.1C5E6300"><link rel="Edit-Time-Data" href="cid:editdata.mso"><style></style> </head> <body lang="EN-US" link="#0563C1" vlink="#954F72" style="tab-interval:.5in;word-wrap:break-word"> <div class="WordSection1"> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman"">Hi Jeff,<o:p></o:p></span></p> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman""><o:p> </o:p></span></p> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman"">I see.<span style="mso-spacerun:yes"> </span>I missed the file rename line in the git patch.<o:p></o:p></span></p> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman""><o:p> </o:p></span></p> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman"">I think the description needs to be expanded to clearly describe the production and consumption of this device path with this GUID.<o:p></o:p></span></p> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman""><o:p> </o:p></span></p> <ol style="margin-top:0in" start="1" type="1"> <li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman"">What component creates the UEFI handle with the Device Path Protocol and the LoadFile2 Protocol with the <span class="SpellE">initrd</span> image?<span style="mso-spacerun:yes"> </span>Is it the platform FW or the OS Loader?<span style="mso-spacerun:yes"> </span> If it is the platform FW, then how does the platform FW know which <span class="SpellE"> initrd</span> image to publish if there are multiple Linux OSes installed?<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman"">What component locates the UEFI handle with the Device Path Protocol and the LoadFile2 Protocol with the <span class="SpellE">initrd</span> image?<span style="mso-spacerun:yes"> </span>It is another stage of the OS Loader or the OS Kernel?<span style="mso-spacerun:yes"> </span>Given that these handles are only available before <span class="SpellE">ExitBootServices</span>, I think this means that the component that locates the <span class="SpellE">initrd</span> image has to do so before <span class="SpellE"> ExitBootServices</span> is called.<o:p></o:p></span></li></ol> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman""><o:p> </o:p></span></p> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman"">Thanks,<o:p></o:p></span></p> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman""><o:p> </o:p></span></p> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman"">Mike<o:p></o:p></span></p> <p class="MsoNormal"><span style="mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman""><o:p> </o:p></span></p> <div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt"> <div> <div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in"> <p class="MsoNormal"><b><span style="mso-fareast-font-family:"Times New Roman"">From:</span></b><span style="mso-fareast-font-family:"Times New Roman""> Jeff Brasen <jbrasen@nvidia.com> <br> <b>Sent:</b> Wednesday, July 21, 2021 10:26 AM<br> <b>To:</b> Kinney, Michael D <michael.d.kinney@intel.com>; Ard Biesheuvel <ardb@kernel.org><br> <b>Cc:</b> devel@edk2.groups.io; ardb+tianocore@kernel.org; Justen, Jordan L <jordan.l.justen@intel.com>; gaoliming@byosoft.com.cn; Liu, Zhiguang <zhiguang.liu@intel.com>; Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com><br> <b>Subject:</b> Re: [edk2-devel] [PATCH 1/1] MdePkg: add definition of LINUX_EFI_INITRD_MEDIA_GUID<o:p></o:p></span></p> </div> </div> <p class="MsoNormal"><o:p> </o:p></p> <div> <p class="MsoNormal"><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black">Does this look good for text to add<o:p></o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black"><o:p> </o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black">"</span><span style="mso-fareast-font-family:"Times New Roman";color:black;background:white">Linux distro boot generally relies on an initial ramdisk (initrd)</span><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black"><br> </span><span style="mso-fareast-font-family:"Times New Roman";color:black;background:white">which is provided by the loader, and which contains additional kernel</span><span style="mso-fareast-font-family:"Times New Roman";color:black"><br> <span style="background:white">modules (for storage and network, for instance), and the initial user</span><br> <span style="background:white">space startup code, i.e., the code which brings up the user space side</span><br> <span style="background:white">of the entire OS.<br> </span></span><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black"><br> In order to provide a standard method to locate this file,<o:p></o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black">the GUID defined in this file is used to describe the device path<o:p></o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black">for a LoadFile2 Protocol instance that is responsible for loading the initrd file"<o:p></o:p></span></p> </div> <div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black"><o:p> </o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black"><o:p> </o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black">Also, the patch does have<o:p></o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-family:"Segoe UI",sans-serif;mso-fareast-font-family:"Times New Roman";color:#201F1E;background:white"> {OvmfPkg => MdePkg}/Include/Guid/LinuxEfiInitrdMedia.h | 0</span><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black"><br> </span><span style="font-family:"Segoe UI",sans-serif;mso-fareast-font-family:"Times New Roman";color:#201F1E;background:white"> 3 files changed, 5 insertions(+), 1 deletion(-)</span><span style="font-family:"Segoe UI",sans-serif;mso-fareast-font-family:"Times New Roman";color:#201F1E"><br> <span style="background:white"> rename {OvmfPkg => MdePkg}/Include/Guid/LinuxEfiInitrdMedia.h (100%)</span><br> </span><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black">[snip]</span><span style="font-family:"Segoe UI",sans-serif;mso-fareast-font-family:"Times New Roman";color:#201F1E"><br> <span style="background:white">diff --git a/OvmfPkg/Include/Guid/LinuxEfiInitrdMedia.h b/MdePkg/Include/Guid/LinuxEfiInitrdMedia.h</span><br> <span style="background:white">similarity index 100%</span><br> <span style="background:white">rename from OvmfPkg/Include/Guid/LinuxEfiInitrdMedia.h</span><br> <span style="background:white">rename to MdePkg/Include/Guid/LinuxEfiInitrdMedia.h</span></span><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black"><o:p></o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black"><o:p> </o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;mso-fareast-font-family:"Times New Roman";color:black"><o:p> </o:p></span></p> </div> <div id="Signature"> <div> <p>Thanks,<o:p></o:p></p> <p>Jeff<o:p></o:p></p> </div> </div> </div> <div class="MsoNormal" align="center" style="text-align:center"><span style="mso-fareast-font-family:"Times New Roman""> <hr size="2" width="98%" align="center"> </span></div> <div id="divRplyFwdMsg"> <p class="MsoNormal" style="mso-outline-level:1"><b><span style="mso-fareast-font-family:"Times New Roman";color:black">From:</span></b><span style="mso-fareast-font-family:"Times New Roman";color:black"> Kinney, Michael D <<a href="mailto:michael.d.kinney@intel.com">michael.d.kinney@intel.com</a>><br> <b>Sent:</b> Wednesday, July 21, 2021 9:38 AM<br> <b>To:</b> Jeff Brasen <<a href="mailto:jbrasen@nvidia.com">jbrasen@nvidia.com</a>>; Ard Biesheuvel <<a href="mailto:ardb@kernel.org">ardb@kernel.org</a>>; Kinney, Michael D <<a href="mailto:michael.d.kinney@intel.com">michael.d.kinney@intel.com</a>><br> <b>Cc:</b> <a href="mailto:devel@edk2.groups.io">devel@edk2.groups.io</a> <<a href="mailto:devel@edk2.groups.io">devel@edk2.groups.io</a>>; <a href="mailto:ardb+tianocore@kernel.org">ardb+tianocore@kernel.org</a> <<a href="mailto:ardb+tianocore@kernel.org">ardb+tianocore@kernel.org</a>>; Justen, Jordan L <<a href="mailto:jordan.l.justen@intel.com">jordan.l.justen@intel.com</a>>; <a href="mailto:gaoliming@byosoft.com.cn">gaoliming@byosoft.com.cn</a> <<a href="mailto:gaoliming@byosoft.com.cn">gaoliming@byosoft.com.cn</a>>; Liu, Zhiguang <<a href="mailto:zhiguang.liu@intel.com">zhiguang.liu@intel.com</a>>; Samer El-Haj-Mahmoud <<a href="mailto:Samer.El-Haj-Mahmoud@arm.com">Samer.El-Haj-Mahmoud@arm.com</a>><br> <b>Subject:</b> RE: [edk2-devel] [PATCH 1/1] MdePkg: add definition of LINUX_EFI_INITRD_MEDIA_GUID</span><span style="mso-fareast-font-family:"Times New Roman""> <o:p></o:p></span></p> <div> <p class="MsoNormal"><span style="mso-fareast-font-family:"Times New Roman""> <o:p></o:p></span></p> </div> </div> <div> <table class="MsoNormalTable" border="1" cellspacing="3" cellpadding="0" style="mso-cellspacing:1.5pt;background:#FFEB9C;mso-yfti-tbllook:1184"> <tbody> <tr style="mso-yfti-irow:0;mso-yfti-firstrow:yes;mso-yfti-lastrow:yes"> <td style="padding:.75pt .75pt .75pt .75pt"> <p class="MsoNormal"><b><span style="font-size:7.5pt;font-family:"Verdana",sans-serif;mso-fareast-font-family:"Times New Roman";color:black">External email: Use caution opening links or attachments</span></b><span style="font-size:7.5pt;font-family:"Verdana",sans-serif;mso-fareast-font-family:"Times New Roman";color:black"> </span><span style="mso-fareast-font-family:"Times New Roman""><o:p></o:p></span></p> </td> </tr> </tbody> </table> <p class="MsoNormal"><span style="mso-fareast-font-family:"Times New Roman""><o:p> </o:p></span></p> <div> <div> <p class="xmsonormal">Hi Ard,<o:p></o:p></p> <p class="xmsonormal"> <o:p></o:p></p> <p class="xmsonormal">If this device path node is considered as part of the standard interface between the Linux kernel and <o:p></o:p></p> <p class="xmsonormal">firmware, then it does make sense for it to be in the <span class="xspelle"> MdePkg</span>. We usually try to reference a public<o:p></o:p></p> <p class="xmsonormal">specification in the include file that defines the interface.<o:p></o:p></p> <p class="xmsonormal"> <o:p></o:p></p> <p class="xmsonormal">In this case, since there is no public document, but it is part of the Linux kernel assumptions,<o:p></o:p></p> <p class="xmsonormal">can the include file for the GUID provide pointers to the Linux kernel that uses the GUID and<o:p></o:p></p> <p class="xmsonormal">describe how the GUID is produced by the FW and consumed by the Linux kernel?<o:p></o:p></p> <p class="xmsonormal"> <o:p></o:p></p> <p class="xmsonormal">I also see that this patch appears to be incomplete. There is an <span class="xspelle">OvmfPkg</span>/Include/<span class="xspelle">Guid</span>/<span class="xspelle">LinuxEfiInitrdMedia.h</span><o:p></o:p></p> <p class="xmsonormal">file in the <span class="xspelle">OvmfPkg</span>. Shouldn’t that file also be moved to the <span class="xspelle">MdePkg</span> as part of this patch?<o:p></o:p></p> <p class="xmsonormal"> <o:p></o:p></p> <p class="xmsonormal">Thanks,<o:p></o:p></p> <p class="xmsonormal"> <o:p></o:p></p> <p class="xmsonormal">Mike<o:p></o:p></p> <p class="xmsonormal"> <o:p></o:p></p> <div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt"> <div> <div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in"> <p class="xmsonormal" style="mso-outline-level:1"><b>From:</b> Jeff Brasen <<a href="mailto:jbrasen@nvidia.com">jbrasen@nvidia.com</a>> <br> <b>Sent:</b> Tuesday, July 20, 2021 9:59 AM<br> <b>To:</b> Ard Biesheuvel <<a href="mailto:ardb@kernel.org">ardb@kernel.org</a>>; Kinney, Michael D <<a href="mailto:michael.d.kinney@intel.com">michael.d.kinney@intel.com</a>><br> <b>Cc:</b> <a href="mailto:devel@edk2.groups.io">devel@edk2.groups.io</a>; <a href="mailto:ardb+tianocore@kernel.org"> ardb+tianocore@kernel.org</a>; Justen, Jordan L <<a href="mailto:jordan.l.justen@intel.com">jordan.l.justen@intel.com</a>>; <a href="mailto:gaoliming@byosoft.com.cn">gaoliming@byosoft.com.cn</a>; Liu, Zhiguang <<a href="mailto:zhiguang.liu@intel.com">zhiguang.liu@intel.com</a>>; Samer El-Haj-Mahmoud <<a href="mailto:Samer.El-Haj-Mahmoud@arm.com">Samer.El-Haj-Mahmoud@arm.com</a>><br> <b>Subject:</b> Re: [edk2-devel] [PATCH 1/1] MdePkg: add definition of LINUX_EFI_INITRD_MEDIA_GUID<o:p></o:p></p> </div> </div> <p class="xmsonormal"> <o:p></o:p></p> <div> <p class="xmsonormal"><span style="font-size:12.0pt;color:black">In my opinion MdePkg is where this should be as it is meant to be used by multiple software entities (linux kernel, grub, edk2, coreboot w/ uefi binding) and probably should be documented in some spec (Although, I am not sure which one would make sense)</span><o:p></o:p></p> </div> <div> <p class="xmsonormal"><span style="font-size:12.0pt;color:black"> </span><o:p></o:p></p> </div> <div> <p class="xmsonormal"><span style="font-size:12.0pt;color:black">I am fine with MdeModulePkg as well though.</span><o:p></o:p></p> </div> <div> <div> <p class="xmsonormal"><span style="font-size:12.0pt;color:black"> </span><o:p></o:p></p> </div> <div id="x_Signature"> <div> <p>Thanks,<o:p></o:p></p> <p>Jeff<o:p></o:p></p> </div> </div> </div> <div class="MsoNormal" align="center" style="text-align:center"><span style="mso-fareast-font-family:"Times New Roman""> <hr size="1" width="98%" align="center"> </span></div> <div id="x_divRplyFwdMsg"> <p class="xmsonormal" style="mso-outline-level:1"><b><span style="color:black">From:</span></b><span style="color:black"> Ard Biesheuvel <<a href="mailto:ardb@kernel.org">ardb@kernel.org</a>><br> <b>Sent:</b> Friday, July 16, 2021 9:56 AM<br> <b>To:</b> Kinney, Michael D <<a href="mailto:michael.d.kinney@intel.com">michael.d.kinney@intel.com</a>><br> <b>Cc:</b> Jeff Brasen <<a href="mailto:jbrasen@nvidia.com">jbrasen@nvidia.com</a>>; <a href="mailto:devel@edk2.groups.io">devel@edk2.groups.io</a> <<a href="mailto:devel@edk2.groups.io">devel@edk2.groups.io</a>>; <a href="mailto:ardb+tianocore@kernel.org">ardb+tianocore@kernel.org</a> <<a href="mailto:ardb+tianocore@kernel.org">ardb+tianocore@kernel.org</a>>; Justen, Jordan L <<a href="mailto:jordan.l.justen@intel.com">jordan.l.justen@intel.com</a>>; <a href="mailto:gaoliming@byosoft.com.cn">gaoliming@byosoft.com.cn</a> <<a href="mailto:gaoliming@byosoft.com.cn">gaoliming@byosoft.com.cn</a>>; Liu, Zhiguang <<a href="mailto:zhiguang.liu@intel.com">zhiguang.liu@intel.com</a>>; Samer El-Haj-Mahmoud <<a href="mailto:Samer.El-Haj-Mahmoud@arm.com">Samer.El-Haj-Mahmoud@arm.com</a>><br> <b>Subject:</b> Re: [edk2-devel] [PATCH 1/1] MdePkg: add definition of LINUX_EFI_INITRD_MEDIA_GUID</span> <o:p></o:p></p> <div> <p class="xmsonormal"> <o:p></o:p></p> </div> </div> <div> <div> <p class="xmsonormal">External email: Use caution opening links or attachments<br> <br> <br> On Fri, 16 Jul 2021 at 17:00, Kinney, Michael D<br> <<a href="mailto:michael.d.kinney@intel.com">michael.d.kinney@intel.com</a>> wrote:<br> ><br> > Hi Ard,<br> ><br> > I see you were involved in the OS side changes.<br> ><br> > Can you explain what is required for the FW <-> OS interface with respect to Load File Protocol and this media device path node.<br> ><br> > What happens if this media device path node is not present? What breaks?<br> ><br> > Trying to figure out if this is a required interop feature (MdePkg candidate) or an EDK II specific extension (MdeModulePkg candidate).<br> ><br> <br> Let me give some context first:<br> <br> Linux distro boot generally relies on an initial ramdisk (initrd)<br> which is provided by the loader, and which contains additional kernel<br> modules (for storage and netwerk, for instance), and the initial user<br> space startup code, ie., the code which brings up the user space side<br> of the entire OS.<br> <br> Before we introduced this media path, the only way for a EFI pre-OS<br> loader (such as GRUB) to provide this initrd was to copy it into DRAM<br> somewhere, and use a arch-specific method of passing the DRAM address<br> and size to the OS (x86 uses struct bootparam, whereas ARM uses device<br> tree). It also requires knowledge on the part of GRUB regarding which<br> parts of DRAM are suitable for holding an initrd image. For measured<br> boot scenarios, it may be an advantage not to have the initrd linger<br> in DRAM for longer that necessary, and we actually intend to measure<br> the initrd loaded via the new method right after it has been loaded<br> this way.<br> <br> To avoid extending this to other architectures such as RISC-V, I<br> decided to introduce a special vendor media path for Linux initrd<br> images, which GRUB et al can implement, which provides the initrd<br> image when the OS loader that consumes it asks for it.<br> <br> So for Linux on x86 or ARM, this is optional, given that support for<br> the old method is not going away any time soon. For RISC-V, I<br> suggested that only the new method be implemented, but I am not sure<br> what the status is there. Note that many embedded style systems don't<br> use GRUB, and may not use initrds to begin with. OTOH, U-Boot also<br> implements support for the Linux initrd vendor media path, and work is<br> ongoing to add measured boot support as well.<br> <br> In any case, I don't have a strong preference where this should live,<br> as long as it is in a generic place where all architectures can use<br> it.<br> <br> --<br> Ard.<o:p></o:p></p> </div> </div> </div> </div> </div> </div> </div> </div> </body> </html> <div width="1" style="color:white;clear:both">_._,_._,_</div> <hr> Groups.io Links:<p> You receive all messages sent to this group. <p> <a target="_blank" href="https://edk2.groups.io/g/devel/message/78039">View/Reply Online (#78039)</a> | | <a target="_blank" href="https://groups.io/mt/84231808/1813853">Mute This Topic</a> | <a href="https://edk2.groups.io/g/devel/post">New Topic</a><br> <a href="https://edk2.groups.io/g/devel/editsub/1813853">Your Subscription</a> | <a href="mailto:devel+owner@edk2.groups.io">Contact Group Owner</a> | <a href="https://edk2.groups.io/g/devel/unsub">Unsubscribe</a> [edk2-devel-archive@redhat.com]<br> <div width="1" style="color:white;clear:both">_._,_._,_</div>