[efi] Implement the EFI_PXE_BASE_CODE_PROTOCOL

Many UEFI NBPs expect to find an EFI_PXE_BASE_CODE_PROTOCOL installed in addition to the EFI_SIMPLE_NETWORK_PROTOCOL. Most NBPs use the EFI_PXE_BASE_CODE_PROTOCOL only to retrieve the cached DHCP packets. This implementation has been tested with grub.efi, shim.efi, syslinux.efi, and wdsmgfw.efi. Some methods (such as Discover() and Arp()) are not used by any known NBP and so have not (yet) been implemented. Usage notes for the tested bootstraps are: - grub.efi uses EFI_PXE_BASE_CODE_PROTOCOL only to retrieve the cached DHCP packet, and uses no other methods. - shim.efi uses EFI_PXE_BASE_CODE_PROTOCOL to retrieve the cached DHCP packet and to retrieve the next NBP via the Mtftp() method. If shim.efi was downloaded via HTTP (or other non-TFTP protocol) then shim.efi will blindly call Mtftp() with an HTTP URI as the filename: this allows the next NBP (e.g. grubx64.efi) to also be transparently retrieved by HTTP. shim.efi can also use the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL to retrieve files previously loaded by "imgfetch" or similar commands in iPXE. The current implementation of shim.efi will use the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL only if it does not find an EFI_PXE_BASE_CODE_PROTOCOL; this patch therefore prevents this usage of our EFI_SIMPLE_FILE_SYSTEM_PROTOCOL. This logic could be trivially reversed in shim.efi if needed. - syslinux.efi uses EFI_PXE_BASE_CODE_PROTOCOL only to retrieve the cached DHCP packet. Versions 6.03 and earlier have a bug which may cause syslinux.efi to attach to the wrong NIC if there are multiple NICs in the system (or if the UEFI firmware supports IPv6). - wdsmgfw.efi (ab)uses EFI_PXE_BASE_CODE_PROTOCOL to retrieve the cached DHCP packets, and to send and retrieve UDP packets via the UdpWrite() and UdpRead() methods. (This was presumably done in order to minimise the amount of benefit obtainable by switching to UEFI, by replicating all of the design mistakes present in the original PXE specification.) The EFI_DOWNGRADE_UX configuration option remains available for now, until this implementation has received more widespread testing. Signed-off-by: Michael Brown <mcb30@ipxe.org>
ipxe · Sep 2, 2015 · 3376fa5 · 3376fa5
1 parent 53d2d9e
commit 3376fa5
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diff --git a/src/image/efi_image.c b/src/image/efi_image.c
@@ -29,6 +29,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/efi/efi_utils.h>
 #include <ipxe/efi/efi_strings.h>
 #include <ipxe/efi/efi_wrap.h>
+#include <ipxe/efi/efi_pxe.h>
 #include <ipxe/image.h>
 #include <ipxe/init.h>
 #include <ipxe/features.h>
@@ -159,6 +160,13 @@ static int efi_image_exec ( struct image *image ) {
 		goto err_file_install;
 	}
 
+	/* Install PXE base code protocol */
+	if ( ( rc = efi_pxe_install ( snpdev->handle, snpdev->netdev ) ) != 0 ){
+		DBGC ( image, "EFIIMAGE %p could not install PXE protocol: "
+		       "%s\n", image, strerror ( rc ) );
+		goto err_pxe_install;
+	}
+
 	/* Install iPXE download protocol */
 	if ( ( rc = efi_download_install ( snpdev->handle ) ) != 0 ) {
 		DBGC ( image, "EFIIMAGE %p could not install iPXE download "
@@ -266,6 +274,8 @@ static int efi_image_exec ( struct image *image ) {
  err_image_path:
 	efi_download_uninstall ( snpdev->handle );
  err_download_install:
+	efi_pxe_uninstall ( snpdev->handle );
+ err_pxe_install:
 	efi_file_uninstall ( snpdev->handle );
  err_file_install:
  err_no_snpdev:

diff --git a/src/include/ipxe/efi/efi_pxe.h b/src/include/ipxe/efi/efi_pxe.h
@@ -0,0 +1,17 @@
+#ifndef _IPXE_EFI_PXE_H
+#define _IPXE_EFI_PXE_H
+
+/** @file
+ *
+ * EFI PXE base code protocol
+ */
+
+#include <ipxe/efi/efi.h>
+#include <ipxe/netdevice.h>
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+extern int efi_pxe_install ( EFI_HANDLE handle, struct net_device *netdev );
+extern void efi_pxe_uninstall ( EFI_HANDLE handle );
+
+#endif /* _IPXE_EFI_PXE_H */
diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
@@ -339,6 +339,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #define ERRFILE_vmbus		      ( ERRFILE_OTHER | 0x00470000 )
 #define ERRFILE_efi_time	      ( ERRFILE_OTHER | 0x00480000 )
 #define ERRFILE_efi_watchdog	      ( ERRFILE_OTHER | 0x00490000 )
+#define ERRFILE_efi_pxe		      ( ERRFILE_OTHER | 0x004a0000 )
 
 /** @} */