ifdfake - Create an IFD with just a section layout

This new tool called `ifdfake` just creates an empty Intel Firmware
Descriptor (IFD) and writes the IFD signature plus the section layout
given on the command line.

    usage: ifdfake [(-b|-m|-g|-p) <start>:<end>]... <output file>

       -b | --bios       <start>:<end>   BIOS region
       -m | --me         <start>:<end>   Intel ME region
       -g | --gbe        <start>:<end>   Gigabit Ethernet region
       -p | --platform   <start>:<end>   Platform Data region
       -h | --help                       print this help

    <start> and <end> bounds are given in Bytes, the <end> bound is inclusive.
    All regions must be multiples of 4K in size and 4K aligned.
    The descriptor region always resides in the first 4K.

    An IFD created with ifdfake won't work as a replacement for a real IFD.
    Never try to flash such an IFD to your board!

The output of ifdfake can be utilized to build an image with just the
later added sections (like coreboot itself) being valid. The resulting
image can then be partially written to a machines flash ROM to just
update coreboot (i.e. the BIOS section).

Change-Id: I925b47cab5c6d490a79d684bdd7a7a45ac442640
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/3523
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 208 insertions, 0 deletions

diff --git a/util/ifdfake/ifdfake.c b/util/ifdfake/ifdfake.c
new file mode 100644
index 0000000000..8eb34a9972
--- /dev/null
+++ b/util/ifdfake/ifdfake.c
@@ -0,0 +1,208 @@
+/*
+ * ifdfake - Create an Intel Firmware Descriptor with just a section layout
+ *
+ * Copyright (C) 2013 secunet Security Networks AG
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+
+#define FDBAR_OFFSET 0x10
+#define FRBA_OFFSET 0x40
+
+typedef struct {
+	uint32_t base, limit, size;
+} region_t;
+
+static void write_image(const region_t regions[], const char *const image)
+{
+	FILE *const f = fopen(image, "w");
+	if (!f) {
+		perror("Could not open file");
+		exit(EXIT_FAILURE);
+	}
+
+	if (fseek(f, 0x1000 - 1, SEEK_SET)) {
+		perror("Failed to seek to end of descriptor");
+		exit(EXIT_FAILURE);
+	}
+	char zero = '\0';
+	if (fwrite(&zero, 1, 1, f) != 1) {
+		fprintf(stderr, "Failed to write at end of descriptor.\n");
+		exit(EXIT_FAILURE);
+	}
+
+	if (fseek(f, FDBAR_OFFSET, SEEK_SET)) {
+		perror("Failed to seek to fdbar");
+		exit(EXIT_FAILURE);
+	}
+
+	struct {
+		uint32_t flvalsig;
+		uint32_t flmap0;
+	} fdbar;
+	memset(&fdbar, 0x00, sizeof(fdbar));
+	fdbar.flvalsig = 0x0ff0a55a;
+	fdbar.flmap0 = (FRBA_OFFSET >> 4) << 16;
+	if (fwrite(&fdbar, sizeof(fdbar), 1, f) != 1) {
+		fprintf(stderr, "Failed to write fdbar.\n");
+		exit(EXIT_FAILURE);
+	}
+
+	int i;
+	uint32_t frba[5];
+	for (i = 0; i < 5; ++i) {
+		if (regions[i].size)
+			frba[i] = ((regions[i].limit & 0xfff000) << (16 - 12)) |
+				  ((regions[i].base & 0xfff000) >> 12);
+		else
+			frba[i] = 0x00000fff;
+	}
+
+	if (fseek(f, FRBA_OFFSET, SEEK_SET)) {
+		perror("Failed to seek to frba");
+		exit(EXIT_FAILURE);
+	}
+	if (fwrite(frba, sizeof(frba), 1, f) != 1) {
+		fprintf(stderr, "Failed to write frba.\n");
+		exit(EXIT_FAILURE);
+	}
+
+	fclose(f);
+}
+
+static int parse_region(const char *_arg, region_t *const region)
+{
+	char *const start = strdup(_arg);
+	if (!start) {
+		fprintf(stderr, "Out of memory.\n");
+		exit(EXIT_FAILURE);
+	}
+
+	char *const colon = strchr(start, ':');
+	if (!colon) {
+		free(start);
+		return -1;
+	}
+	*colon = '\0';
+
+	char *const end = colon + 1;
+
+	errno = 0;
+	region->base = strtoul(start, NULL, 0);
+	region->limit = strtoul(end, NULL, 0);
+	region->size = region->limit - region->base + 1;
+
+	free(start);
+	if (errno) {
+		perror("Failed to parse region");
+		return -1;
+	} else {
+		return 0;
+	}
+}
+
+static void print_usage(const char *name)
+{
+	printf("usage: %s [(-b|-m|-g|-p) <start>:<end>]... <output file>\n", name);
+	printf("\n"
+	       "   -b | --bios       <start>:<end>   BIOS region\n"
+	       "   -m | --me         <start>:<end>   Intel ME region\n"
+	       "   -g | --gbe        <start>:<end>   Gigabit Ethernet region\n"
+	       "   -p | --platform   <start>:<end>   Platform Data region\n"
+	       "   -h | --help                       print this help\n\n"
+	       "<start> and <end> bounds are given in bytes, the <end> bound is inclusive.\n"
+	       "All regions must be multiples of 4K in size and 4K aligned.\n"
+	       "The descriptor region always resides in the first 4K.\n\n"
+	       "An IFD created with ifdfake won't work as a replacement for a real IFD.\n"
+	       "Never try to flash such an IFD to your board!\n\n");
+}
+
+int main(int argc, char *argv[])
+{
+	int opt, option_index = 0, idx;
+	region_t regions[5];
+
+	memset(regions, 0x00, sizeof(regions));
+
+	static struct option long_options[] = {
+		{"bios", 1, NULL, 'b'},
+		{"me", 1, NULL, 'm'},
+		{"gbe", 1, NULL, 'g'},
+		{"platform", 1, NULL, 'p'},
+		{"help", 0, NULL, 'h'},
+		{0, 0, 0, 0}
+	};
+
+	while ((opt = getopt_long(argc, argv, "b:m:g:p:h?",
+				  long_options, &option_index)) != EOF) {
+		switch (opt) {
+		case 'b': case 'm': case 'g': case 'p':
+			switch (opt) {
+				case 'b': idx = 1; break;
+				case 'm': idx = 2; break;
+				case 'g': idx = 3; break;
+				case 'p': idx = 4; break;
+				default:  idx = 0; break; /* can't happen */
+			}
+			if (parse_region(optarg, &regions[idx])) {
+				print_usage(argv[0]);
+				exit(EXIT_FAILURE);
+			}
+			break;
+		case 'h':
+		case '?':
+		default:
+			print_usage(argv[0]);
+			exit(EXIT_SUCCESS);
+			break;
+		}
+	}
+
+	if (optind + 1 != argc) {
+		fprintf(stderr, "No output file given.\n\n");
+		print_usage(argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	regions[0].base   = 0x00000000;
+	regions[0].limit  = 0x00000fff;
+	regions[0].size   = 0x00001000;
+	for (idx = 1; idx < 5; ++idx) {
+		if (regions[idx].size) {
+			if (regions[idx].base & 0xfff)
+				fprintf(stderr, "Region %d is "
+					"not 4K aligned.\n", idx);
+			else if (regions[idx].size & 0xfff)
+				fprintf(stderr, "Region %d size is "
+					"no multiple of 4K.\n", idx);
+			else if (regions[idx].limit <= regions[idx].base)
+				fprintf(stderr, "Region %d is empty.\n", idx);
+			else
+				continue;
+			print_usage(argv[0]);
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	write_image(regions, argv[optind]);
+
+	return 0;
+}