When loading a device tree using the "mach dtb" command, give firmware

a chance to make modifications (such as applying memory reservations)
by using the EFI devicetree fixup protocol.

ok jca@

3 files changed, 68 insertions, 6 deletions

diff --git a/sys/arch/armv7/stand/efiboot/conf.c b/sys/arch/armv7/stand/efiboot/conf.c
index de536fb9620..4143b4f5c46 100644
--- a/sys/arch/armv7/stand/efiboot/conf.c
+++ b/sys/arch/armv7/stand/efiboot/conf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: conf.c,v 1.35 2024/03/10 15:37:54 kettenis Exp $	*/
+/*	$OpenBSD: conf.c,v 1.36 2024/06/17 09:12:45 kettenis Exp $	*/
 
 /*
  * Copyright (c) 1996 Michael Shalayeff
@@ -42,7 +42,7 @@
 #include "efidev.h"
 #include "efipxe.h"
 
-const char version[] = "1.22";
+const char version[] = "1.23";
 int	debug = 0;
 
 struct fs_ops file_system[] = {
diff --git a/sys/arch/armv7/stand/efiboot/efiboot.c b/sys/arch/armv7/stand/efiboot/efiboot.c
index c6bf9501ebd..0e5ac7dcaa5 100644
--- a/sys/arch/armv7/stand/efiboot/efiboot.c
+++ b/sys/arch/armv7/stand/efiboot/efiboot.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: efiboot.c,v 1.40 2022/12/22 15:44:02 kettenis Exp $	*/
+/*	$OpenBSD: efiboot.c,v 1.41 2024/06/17 09:12:45 kettenis Exp $	*/
 
 /*
  * Copyright (c) 2015 YASUOKA Masahiko <yasuoka@yasuoka.net>
@@ -36,6 +36,7 @@
 
 #include "efidev.h"
 #include "efiboot.h"
+#include "efidt.h"
 #include "fdt.h"
 
 EFI_SYSTEM_TABLE	*ST;
@@ -59,6 +60,7 @@ static EFI_GUID		 blkio_guid = BLOCK_IO_PROTOCOL;
 static EFI_GUID		 devp_guid = DEVICE_PATH_PROTOCOL;
 static EFI_GUID		 gop_guid = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
 static EFI_GUID		 fdt_guid = FDT_TABLE_GUID;
+static EFI_GUID		 dt_fixup_guid = EFI_DT_FIXUP_PROTOCOL_GUID;
 
 #define efi_guidcmp(_a, _b)	memcmp((_a), (_b), sizeof(EFI_GUID))
 
@@ -1004,12 +1006,18 @@ efi_fdt(void)
 	return fdt_sys;
 }
 
+#define EXTRA_DT_SPACE	(32 * 1024)
+
 int
 fdt_load_override(char *file)
 {
+	EFI_DT_FIXUP_PROTOCOL *dt_fixup;
 	EFI_PHYSICAL_ADDRESS addr;
 	char path[MAXPATHLEN];
+	EFI_STATUS status;
 	struct stat sb;
+	size_t dt_size;
+	UINTN sz;
 	int fd;
 
 	if (file == NULL && fdt_override) {
@@ -1027,7 +1035,8 @@ fdt_load_override(char *file)
 		printf("cannot open %s\n", path);
 		return 0;
 	}
-	if (efi_memprobe_find(EFI_SIZE_TO_PAGES(sb.st_size),
+	dt_size = sb.st_size + EXTRA_DT_SPACE;
+	if (efi_memprobe_find(EFI_SIZE_TO_PAGES(dt_size),
 	    PAGE_SIZE, EfiLoaderData, &addr) != EFI_SUCCESS) {
 		printf("cannot allocate memory for %s\n", path);
 		return 0;
@@ -1037,9 +1046,18 @@ fdt_load_override(char *file)
 		return 0;
 	}
 
+	status = BS->LocateProtocol(&dt_fixup_guid, NULL, (void **)&dt_fixup);
+	if (status == EFI_SUCCESS) {
+		sz = dt_size;
+		status = dt_fixup->Fixup(dt_fixup, (void *)addr, &sz,
+		    EFI_DT_APPLY_FIXUPS | EFI_DT_RESERVE_MEMORY);
+		if (status != EFI_SUCCESS)
+			panic("DT fixup failed: 0x%lx", status);
+	}
+
 	if (!fdt_init((void *)addr)) {
 		printf("invalid device tree\n");
-		BS->FreePages(addr, EFI_SIZE_TO_PAGES(sb.st_size));
+		BS->FreePages(addr, EFI_SIZE_TO_PAGES(dt_size));
 		return 0;
 	}
 
@@ -1050,7 +1068,7 @@ fdt_load_override(char *file)
 	}
 
 	fdt_override = (void *)addr;
-	fdt_override_size = sb.st_size;
+	fdt_override_size = dt_size;
 	return 0;
 }
 
diff --git a/sys/arch/armv7/stand/efiboot/efidt.h b/sys/arch/armv7/stand/efiboot/efidt.h
new file mode 100644
index 00000000000..8a2ab0d2c34
--- /dev/null
+++ b/sys/arch/armv7/stand/efiboot/efidt.h
@@ -0,0 +1,44 @@
+/*	$OpenBSD: efidt.h,v 1.1 2024/06/17 09:12:45 kettenis Exp $	*/
+
+/*
+ * Copyright (c) 2024 Mark Kettenis <kettenis@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+
+#include <efi.h>
+#include <efiapi.h>
+
+#define EFI_DT_FIXUP_PROTOCOL_GUID		\
+  { 0xe617d64c, 0xfe08, 0x46da, \
+    { 0xf4, 0xdc, 0xbb, 0xd5, 0x87, 0x0c, 0x73, 0x00 } }
+
+INTERFACE_DECL(_EFI_DT_FIXUP_PROTOCOL);
+
+typedef EFI_STATUS
+(EFIAPI *EFI_DT_FIXUP) (
+    IN struct _EFI_DT_FIXUP_PROTOCOL	*This,
+    IN VOID				*Fdt,
+    IN OUT UINTN			*BufferSize,
+    IN UINT32				Flags
+    );
+
+#define EFI_DT_APPLY_FIXUPS	0x00000001
+#define EFI_DT_RESERVE_MEMORY	0x00000002
+
+typedef struct _EFI_DT_FIXUP_PROTOCOL {
+	UINT64			Revision;
+	EFI_DT_FIXUP		Fixup;
+} EFI_DT_FIXUP_PROTOCOL;