[edk2] BOOTX64.EFI is what?

[T***@zhaoxin.com]

Hello, experts:
I found : Mdepkg\include\uefi\UefiSpec.h has some definitions:
//
// EFI File location to boot from on removable media devices
//
#define EFI_REMOVABLE_MEDIA_FILE_NAME_IA32 L"\\EFI\\BOOT\\BOOTIA32.EFI<file:///\\EFI\BOOT\BOOTIA32.EFI>"
#define EFI_REMOVABLE_MEDIA_FILE_NAME_IA64 L"\\EFI\\BOOT\\BOOTIA64.EFI<file:///\\EFI\BOOT\BOOTIA64.EFI>"
#define EFI_REMOVABLE_MEDIA_FILE_NAME_X64 L"\\EFI\\BOOT\\BOOTX64.EFI<file:///\\EFI\BOOT\BOOTX64.EFI>"
#define EFI_REMOVABLE_MEDIA_FILE_NAME_ARM L"\\EFI\\BOOT\\BOOTARM.EFI<file:///\\EFI\BOOT\BOOTARM.EFI>"

So, my question is:

1. BOOTX64.EFI is what? Is an OS loader?

For example:

Win7’s boot loader should locate at \\EFI\\Microsoft\\Boot\\bootmgfw.efi<file:///\\EFI\Microsoft\Boot\bootmgfw.efi> .

Best wishes,

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[Richardson, Brian]

The \EFI\BOOT\BOOTxxxx.EFI filenames are defined as a default boot file name for removable media. It’s also used as the name of the fallback bootloader on the OS media. Look at the boot partition on an OS install media (USB, CD, DVD) and you’ll see a \EFI\BOOT\BOOTxxxx.EFI file. The boot file can be any UEFI application (UEFI Shell, OS Loader, test utility, boot manager).

An OS specific loader (bootmgfw.efi, grub.efi, 
) will be placed by the OS installer. Those files live in directories with names reserved by the UEFI Forum (\EFI\Microsoft\, \EFI\RedHat, 
) to avoid conflicts. The OS installer will also create a UEFI boot variable in NVRAM (BOOT0001, BOOT0002, 
) with a path to that loader and set it as the top boot order entry.

Thanks ... br
---
Brian Richardson -- ***@intel.com -- Twitter: intel_brian

From: ***@zhaoxin.com [mailto:***@zhaoxin.com]
Sent: Thursday, June 04, 2015 11:14 PM
To: edk2-***@lists.sourceforge.net
Subject: [edk2] BOOTX64.EFI is what?

Hello, experts:
I found : Mdepkg\include\uefi\UefiSpec.h has some definitions:
//
// EFI File location to boot from on removable media devices
//
#define EFI_REMOVABLE_MEDIA_FILE_NAME_IA32 L"\\EFI\\BOOT\\BOOTIA32.EFI<file:///\\EFI\BOOT\BOOTIA32.EFI>"
#define EFI_REMOVABLE_MEDIA_FILE_NAME_IA64 L"\\EFI\\BOOT\\BOOTIA64.EFI<file:///\\EFI\BOOT\BOOTIA64.EFI>"
#define EFI_REMOVABLE_MEDIA_FILE_NAME_X64 L"\\EFI\\BOOT\\BOOTX64.EFI<file:///\\EFI\BOOT\BOOTX64.EFI>"
#define EFI_REMOVABLE_MEDIA_FILE_NAME_ARM L"\\EFI\\BOOT\\BOOTARM.EFI<file:///\\EFI\BOOT\BOOTARM.EFI>"

So, my question is:

1. BOOTX64.EFI is what? Is an OS loader?

For example:

Win7’s boot loader should locate at \\EFI\\Microsoft\\Boot\\bootmgfw.efi<file:///\\EFI\Microsoft\Boot\bootmgfw.efi> .

Best wishes,
本邮件仅针对指定的收件人发送并可胜含有保密或䞓有内容。任䜕非指定收件人所䞺之查阅、蜬发或䜿甚本信息是䞍被允讞的。
劂果悚误收到本邮件请立即告知发件人并删陀本邮件及所有附件。谢谢
The information transmitted in this e-mail is intended only for the addressee and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of this information by persons or entities other than the intended recipient is prohibited. If you received this e-mail in error, please notify the sender immediately, and delete this e-mail and any attachments. Thank you.

[Blibbet]

IMO, it would be useful if the UEFI Forum's ESP Vendor Subdirectory
Registry included the names of their driver/service/app .efi files, and
pointers to their CRL for certificate checks. Especially the boot
loaders/managers and tools that sysadmins might be needed to configure a
system to use. Right now, the registry is IMO not that useful. In
machine readable form, perhaps SPDX or some similar metadata format, so
UEFI users can better verify files on ESP files, most of which are on
ACL-free FAT file systems.

It'll also help the Microsoft Windows defender team build a list of
files to delete. :-)

On 06/05/2015 08:18 AM, Richardson, Brian wrote:
...

An OS specific loader (bootmgfw.efi, grub.efi, …) will be placed by

the OS installer. Those files live in directories with names reserved by
the UEFI Forum (\EFI\Microsoft\, \EFI\RedHat, …) to avoid conflicts. The
OS installer will also create a UEFI boot variable in NVRAM (BOOT0001,
BOOT0002, …) with a path to that loader and set it as the top boot order
entry.


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