util/amdfwtool: Add amdfwread utility

Amdfwtool creates AMD firmware images however there is currently no way
to get information from an existing image. This commit adds amdfwread to
support that functionality. At the moment only reading PSP soft fuse
flags is supported. Example usage: `amdfwread --soft-fuse bios.bin`,
example output: `Soft-fuse:0x400000030000041`.

BUG=b:202397678
TEST=Ran amdfwread and verified that it correctly reads the soft fuse
bits, verified that built AMD FW still boots on DUT

Signed-off-by: Robert Zieba <robertzieba@google.com>
Change-Id: I15fa07c9cad8e4640e9c40e5539b0dab44424850
Reviewed-on: https://review.coreboot.org/c/coreboot/+/62795
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Rob Barnes <robbarnes@google.com>

6 files changed, 286 insertions, 38 deletions

diff --git a/util/amdfwtool/.gitignore b/util/amdfwtool/.gitignore
index cac1859b43..e688fcfa68 100644
--- a/util/amdfwtool/.gitignore
+++ b/util/amdfwtool/.gitignore
@@ -1 +1,2 @@
 amdfwtool
+amdfwread
diff --git a/util/amdfwtool/Makefile b/util/amdfwtool/Makefile
index 7b7793535a..bdc3dc3432 100644
--- a/util/amdfwtool/Makefile
+++ b/util/amdfwtool/Makefile
@@ -2,27 +2,33 @@
 
 HOSTCC ?= cc
 
-SRC = amdfwtool.c data_parse.c
-OBJ = $(SRC:%.c=%.o)
-TARGET = amdfwtool
+READ_SRC = amdfwread.c
+READ_OBJ = $(READ_SRC:%.c=%.o)
+TOOL_SRC = amdfwtool.c data_parse.c
+TOOL_OBJ = $(TOOL_SRC:%.c=%.o)
+HEADER=amdfwtool.h
+TARGETS = amdfwread amdfwtool
 WERROR=-Werror
 CFLAGS=-O2 -Wall -Wextra -Wshadow ${WERROR}
 
-all: $(TARGET)
+all: $(TARGETS)
 
-$(TARGET): $(OBJ)
-	$(CC) $(OBJ) $(LDFLAGS) -o $@
+amdfwread: $(READ_OBJ)
+	$(CC) $(READ_OBJ) $(LDFLAGS) -o $@
+
+amdfwtool: $(TOOL_OBJ)
+	$(CC) $(TOOL_OBJ) $(LDFLAGS) -o $@
 
 %.o: %.c $(HEADER)
 	$(CC) $(CFLAGS) -c -o $@ $<
 
 clean:
-	@rm -f $(TARGET) $(OBJ)
+	@rm -f $(TARGETS) $(READ_OBJ) $(TOOL_OBJ)
 
 distclean: clean
 
 help:
-	@echo "${TARGET}: Create AMD Firmware combination"
+	@echo "${TARGETS}: Tools to create and read from AMD firmware combinations"
 	@echo "Targets: all, clean, distclean, help"
 	@echo "To disable warnings as errors, run make as:"
 	@echo "  make all WERROR=\"\""
diff --git a/util/amdfwtool/amdfwread.c b/util/amdfwtool/amdfwread.c
new file mode 100644
index 0000000000..1a95c5c267
--- /dev/null
+++ b/util/amdfwtool/amdfwread.c
@@ -0,0 +1,237 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#include <getopt.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "amdfwtool.h"
+
+/* An address can be relative to the image/file start but it can also be the address when
+ * the image is mapped at 0xff000000. Used to ensure that we only attempt to read within
+ * the limits of the file. */
+#define FILE_REL_MASK 0xffffff
+
+#define ERR(...) fprintf(stderr, __VA_ARGS__)
+
+/* Possible locations for the header */
+const uint32_t fw_header_offsets[] = {
+	0xfa0000,
+	0xe20000,
+	0xc20000,
+	0x820000,
+	0x020000,
+};
+
+/* Converts addresses to be relative to the start of the file */
+static uint64_t relative_offset(const psp_directory_header *header, uint32_t header_offset,
+	const psp_directory_entry *entry, size_t entry_index)
+{
+	amd_addr_mode mode = header->additional_info_fields.address_mode;
+	if (mode == AMD_ADDR_REL_BIOS) {
+		/* Entry address mode override directory mode with this value */
+		mode = entry->address_mode;
+	}
+
+	switch (mode) {
+	case AMD_ADDR_REL_BIOS:
+		return entry->addr + header_offset;
+
+	case AMD_ADDR_REL_SLOT:
+		return entry->addr + header_offset + sizeof(psp_directory_header) +
+			entry_index * sizeof(psp_directory_entry);
+
+	default:
+		break;
+	}
+
+	return entry->addr & FILE_REL_MASK;
+}
+
+static int read_fw_header(FILE *fw, uint32_t offset, embedded_firmware *fw_header)
+{
+	if (fseek(fw, offset, SEEK_SET) != 0) {
+		ERR("Failed to seek to fw header offset 0x%x\n", offset);
+		return 1;
+	}
+
+	if (fread(fw_header, sizeof(embedded_firmware), 1, fw) != 1) {
+		ERR("Failed to read fw header at 0x%x\n", offset);
+		return 1;
+	}
+
+	return fw_header->signature != EMBEDDED_FW_SIGNATURE;
+}
+
+static int read_psp_directory(FILE *fw, uint32_t offset, uint32_t expected_cookie,
+			psp_directory_header *header, psp_directory_entry **entries,
+			size_t *num_entries)
+{
+	offset &= FILE_REL_MASK;
+
+	if (fseek(fw, offset, SEEK_SET) != 0) {
+		ERR("Failed to seek to PSP header at 0x%x\n", offset);
+		return 1;
+	}
+
+	if (fread(header, sizeof(psp_directory_header), 1, fw) != 1) {
+		ERR("Failed to read PSP header cookie\n");
+		return 1;
+	}
+
+	/* Ensure that we have a PSP directory */
+	if (header->cookie != expected_cookie) {
+		ERR("Invalid PSP header cookie value found: 0x%x, expected: 0x%x\n",
+			expected_cookie, header->cookie);
+		return 1;
+	}
+
+	/* Read the entries */
+	*num_entries = header->num_entries;
+	*entries = malloc(sizeof(psp_directory_entry) * header->num_entries);
+	if (fread(*entries, sizeof(psp_directory_entry), header->num_entries, fw)
+		!= header->num_entries) {
+		ERR("Failed to read %d PSP entries\n", header->num_entries);
+		return 1;
+	}
+
+	return 0;
+}
+
+static int read_soft_fuse(FILE *fw, const embedded_firmware *fw_header)
+{
+	psp_directory_entry *current_entries = NULL;
+	size_t num_current_entries = 0;
+
+	uint32_t psp_offset = 0;
+	/* 0xffffffff indicates that the offset is in new_psp_directory */
+	if (fw_header->psp_directory != 0xffffffff)
+		psp_offset = fw_header->psp_directory;
+	else
+		psp_offset = fw_header->new_psp_directory;
+
+	psp_directory_header header;
+	if (read_psp_directory(fw, psp_offset, PSP_COOKIE, &header,
+		       &current_entries, &num_current_entries) != 0)
+		return 1;
+
+	while (1) {
+		uint32_t l2_dir_offset = 0;
+
+		for (size_t i = 0; i < num_current_entries; i++) {
+			uint32_t type = current_entries[i].type;
+			if (type == AMD_PSP_FUSE_CHAIN) {
+				uint64_t mode = current_entries[i].address_mode;
+				uint64_t addr = current_entries[i].addr;
+				uint64_t fuse = mode << 62 | addr;
+
+				printf("Soft-fuse:0x%lx\n", fuse);
+				return 0;
+			} else if (type == AMD_FW_L2_PTR) {
+				/* There's a second level PSP directory to read */
+				if (l2_dir_offset != 0)
+					return 1;
+
+				l2_dir_offset = relative_offset(&header, psp_offset,
+								&current_entries[i], i);
+			}
+		}
+
+		free(current_entries);
+
+		/* Didn't find an L2 PSP directory so we can stop */
+		if (l2_dir_offset == 0)
+			break;
+
+		/* Read the L2 PSP directory */
+		if (read_psp_directory(fw, l2_dir_offset, PSPL2_COOKIE, &header,
+			       &current_entries, &num_current_entries) != 0)
+			break;
+	}
+
+	return 1;
+}
+
+enum {
+	AMDFW_OPT_HELP = 'h',
+
+	/* When bit 31 is set, options are a bitfield of info to print from the
+	   firmware image. */
+	AMDFW_OPT_SOFT_FUSE = 0xF0000001,
+};
+
+static char const optstring[] = {AMDFW_OPT_HELP};
+
+static struct option long_options[] = {
+	{"help", no_argument, 0, AMDFW_OPT_HELP},
+	{"soft-fuse", no_argument, 0, AMDFW_OPT_SOFT_FUSE},
+};
+
+static void print_usage(void)
+{
+	printf("amdfwread: Examine AMD firmware images\n");
+	printf("Usage: amdfwread [options] <file>\n");
+	printf("--soft-fuse                Print soft fuse value\n");
+}
+
+int main(int argc, char **argv)
+{
+	char *fw_file = NULL;
+
+	int selected_functions = 0;
+	int index = 0;
+	while (1) {
+		int opt = getopt_long(argc, argv, optstring, long_options, &index);
+
+		if (opt == -1) {
+			index++;
+			if (index >= argc) {
+				/* Print usage if we didn't get any arguments */
+				print_usage();
+				return 0;
+			}
+
+			fw_file = argv[index];
+			break;
+		}
+
+		if (opt == AMDFW_OPT_HELP) {
+			print_usage();
+			return 0;
+		}
+
+		selected_functions |= opt;
+	}
+
+	FILE *fw = fopen(fw_file, "rb");
+	if (!fw) {
+		ERR("Failed to open FW file %s\n", fw_file);
+		return 1;
+	}
+
+	/* Find the FW header by checking each possible location */
+	embedded_firmware fw_header;
+	int found_header = 0;
+	for (size_t i = 0; i < ARRAY_SIZE(fw_header_offsets); i++) {
+		if (read_fw_header(fw, fw_header_offsets[i], &fw_header) == 0) {
+			found_header = 1;
+			break;
+		}
+	}
+
+	if (!found_header) {
+		ERR("Failed to find FW header\n");
+		fclose(fw);
+		return 1;
+	}
+
+	if (selected_functions & AMDFW_OPT_SOFT_FUSE) {
+		if (read_soft_fuse(fw, &fw_header) != 0) {
+			fclose(fw);
+			return 1;
+		}
+	}
+
+	fclose(fw);
+	return 0;
+}
diff --git a/util/amdfwtool/amdfwtool.c b/util/amdfwtool/amdfwtool.c
index c58d1e9fc0..abc0a9eb9d 100644
--- a/util/amdfwtool/amdfwtool.c
+++ b/util/amdfwtool/amdfwtool.c
@@ -358,18 +358,13 @@ typedef struct _context {
 	uint32_t current_table;
 } context;
 
-#define ADDRESS_MODE_0_PHY		0
-#define ADDRESS_MODE_1_REL_BIOS		1
-#define ADDRESS_MODE_2_REL_TAB		2
-#define ADDRESS_MODE_3_REL_SLOT		3
-
 #define RUN_BASE(ctx) (0xFFFFFFFF - (ctx).rom_size + 1)
 #define RUN_OFFSET_MODE(ctx, offset, mode) \
-		((mode) == ADDRESS_MODE_0_PHY ? RUN_BASE(ctx) + (offset) :	\
-		((mode) == ADDRESS_MODE_1_REL_BIOS ? (offset) :	\
-		((mode) == ADDRESS_MODE_2_REL_TAB ? (offset) - ctx.current_table : (offset))))
+		((mode) == AMD_ADDR_PHYSICAL ? RUN_BASE(ctx) + (offset) :	\
+		((mode) == AMD_ADDR_REL_BIOS ? (offset) :	\
+		((mode) == AMD_ADDR_REL_TAB ? (offset) - ctx.current_table : (offset))))
 #define RUN_OFFSET(ctx, offset) RUN_OFFSET_MODE((ctx), (offset), (ctx).address_mode)
-#define RUN_TO_OFFSET(ctx, run) ((ctx).address_mode == ADDRESS_MODE_0_PHY ?	\
+#define RUN_TO_OFFSET(ctx, run) ((ctx).address_mode == AMD_ADDR_PHYSICAL ?	\
 				(run) - RUN_BASE(ctx) : (run)) /* TODO: */
 #define RUN_CURRENT(ctx) RUN_OFFSET((ctx), (ctx).current)
 /* The mode in entry can not be higher than the header's.
@@ -385,7 +380,7 @@ typedef struct _context {
 /* Only set the address mode in entry if the table is mode 2. */
 #define SET_ADDR_MODE(table, mode) \
 		((table)->header.additional_info_fields.address_mode ==	\
-		ADDRESS_MODE_2_REL_TAB ? (mode) : 0)
+		AMD_ADDR_REL_TAB ? (mode) : 0)
 #define SET_ADDR_MODE_BY_TABLE(table) \
 		SET_ADDR_MODE((table), (table)->header.additional_info_fields.address_mode)
 
@@ -696,7 +691,7 @@ static void integrate_psp_ab(context *ctx, psp_directory_table *pspdir,
 	pspdir->entries[count].subprog = 0;
 	pspdir->entries[count].rsvd = 0;
 	if (ish != NULL) {
-		ish->pl2_location = BUFF_TO_RUN_MODE(*ctx, pspdir2, ADDRESS_MODE_1_REL_BIOS);
+		ish->pl2_location = BUFF_TO_RUN_MODE(*ctx, pspdir2, AMD_ADDR_REL_BIOS);
 		ish->boot_priority = ab == AMD_FW_RECOVERYAB_A ? 0xFFFFFFFF : 1;
 		ish->update_retry_count = 2;
 		ish->glitch_retry_count = 0;
@@ -704,15 +699,15 @@ static void integrate_psp_ab(context *ctx, psp_directory_table *pspdir,
 		ish->checksum = fletcher32(&ish->boot_priority,
 				sizeof(ish_directory_table) - sizeof(uint32_t));
 		pspdir->entries[count].addr =
-				BUFF_TO_RUN_MODE(*ctx, ish, ADDRESS_MODE_1_REL_BIOS);
+				BUFF_TO_RUN_MODE(*ctx, ish, AMD_ADDR_REL_BIOS);
 		pspdir->entries[count].address_mode =
-				SET_ADDR_MODE(pspdir, ADDRESS_MODE_1_REL_BIOS);
+				SET_ADDR_MODE(pspdir, AMD_ADDR_REL_BIOS);
 		pspdir->entries[count].size = TABLE_ALIGNMENT;
 	} else {
 		pspdir->entries[count].addr =
-				BUFF_TO_RUN_MODE(*ctx, pspdir2, ADDRESS_MODE_1_REL_BIOS);
+				BUFF_TO_RUN_MODE(*ctx, pspdir2, AMD_ADDR_REL_BIOS);
 		pspdir->entries[count].address_mode =
-				SET_ADDR_MODE(pspdir, ADDRESS_MODE_1_REL_BIOS);
+				SET_ADDR_MODE(pspdir, AMD_ADDR_REL_BIOS);
 		pspdir->entries[count].size = pspdir2->header.num_entries *
 				sizeof(psp_directory_entry) +
 				sizeof(psp_directory_header);
@@ -814,9 +809,9 @@ static void integrate_psp_firmwares(context *ctx,
 			pspdir->entries[count].size = ALIGN(bytes,
 							ERASE_ALIGNMENT);
 			pspdir->entries[count].addr =
-				RUN_CURRENT_MODE(*ctx, ADDRESS_MODE_1_REL_BIOS);
+				RUN_CURRENT_MODE(*ctx, AMD_ADDR_REL_BIOS);
 			pspdir->entries[count].address_mode =
-				SET_ADDR_MODE(pspdir, ADDRESS_MODE_1_REL_BIOS);
+				SET_ADDR_MODE(pspdir, AMD_ADDR_REL_BIOS);
 
 			ctx->current = ALIGN(ctx->current + bytes,
 							BLOB_ERASE_ALIGNMENT);
@@ -871,9 +866,9 @@ static void integrate_psp_firmwares(context *ctx,
 					* sizeof(psp_directory_entry);
 
 		pspdir->entries[count].addr =
-				BUFF_TO_RUN_MODE(*ctx, pspdir2, ADDRESS_MODE_1_REL_BIOS);
+				BUFF_TO_RUN_MODE(*ctx, pspdir2, AMD_ADDR_REL_BIOS);
 		pspdir->entries[count].address_mode =
-				SET_ADDR_MODE(pspdir, ADDRESS_MODE_1_REL_BIOS);
+				SET_ADDR_MODE(pspdir, AMD_ADDR_REL_BIOS);
 		count++;
 	}
 
@@ -1092,14 +1087,14 @@ static void integrate_bios_firmwares(context *ctx,
 				/* If source is given, use that and its size */
 				biosdir->entries[count].source = fw_table[i].src;
 				biosdir->entries[count].address_mode =
-						SET_ADDR_MODE(biosdir, ADDRESS_MODE_1_REL_BIOS);
+						SET_ADDR_MODE(biosdir, AMD_ADDR_REL_BIOS);
 				biosdir->entries[count].size = fw_table[i].size;
 			} else {
 				/* Else reserve size bytes within amdfw.rom */
 				ctx->current = ALIGN(ctx->current, ERASE_ALIGNMENT);
 				biosdir->entries[count].source = RUN_CURRENT(*ctx);
 				biosdir->entries[count].address_mode =
-						SET_ADDR_MODE(biosdir, ADDRESS_MODE_1_REL_BIOS);
+						SET_ADDR_MODE(biosdir, AMD_ADDR_REL_BIOS);
 				biosdir->entries[count].size = ALIGN(
 						fw_table[i].size, ERASE_ALIGNMENT);
 				memset(BUFF_CURRENT(*ctx), 0xff,
@@ -1113,7 +1108,7 @@ static void integrate_bios_firmwares(context *ctx,
 			if (level == BDT_LVL1 && locate_bdt2_bios(biosdir2, &source, &size)) {
 				biosdir->entries[count].source = source;
 				biosdir->entries[count].address_mode =
-						SET_ADDR_MODE(biosdir, ADDRESS_MODE_1_REL_BIOS);
+						SET_ADDR_MODE(biosdir, AMD_ADDR_REL_BIOS);
 				biosdir->entries[count].size = size;
 				break;
 			}
@@ -1121,7 +1116,7 @@ static void integrate_bios_firmwares(context *ctx,
 			/* level 2, or level 1 and no copy found in level 2 */
 			biosdir->entries[count].source = fw_table[i].src;
 			biosdir->entries[count].address_mode =
-						SET_ADDR_MODE(biosdir, ADDRESS_MODE_1_REL_BIOS);
+						SET_ADDR_MODE(biosdir, AMD_ADDR_REL_BIOS);
 			biosdir->entries[count].dest = fw_table[i].dest;
 			biosdir->entries[count].size = fw_table[i].size;
 
@@ -1136,9 +1131,9 @@ static void integrate_bios_firmwares(context *ctx,
 			}
 
 			biosdir->entries[count].source =
-				RUN_CURRENT_MODE(*ctx, ADDRESS_MODE_1_REL_BIOS);
+				RUN_CURRENT_MODE(*ctx, AMD_ADDR_REL_BIOS);
 			biosdir->entries[count].address_mode =
-				SET_ADDR_MODE(biosdir, ADDRESS_MODE_1_REL_BIOS);
+				SET_ADDR_MODE(biosdir, AMD_ADDR_REL_BIOS);
 
 			ctx->current = ALIGN(ctx->current + bytes, 0x100U);
 			break;
@@ -1180,7 +1175,7 @@ static void integrate_bios_firmwares(context *ctx,
 		biosdir->entries[count].source =
 					BUFF_TO_RUN(*ctx, biosdir2);
 		biosdir->entries[count].address_mode =
-					SET_ADDR_MODE(biosdir, ADDRESS_MODE_1_REL_BIOS);
+					SET_ADDR_MODE(biosdir, AMD_ADDR_REL_BIOS);
 		biosdir->entries[count].subprog = 0;
 		biosdir->entries[count].inst = 0;
 		biosdir->entries[count].copy = 0;
@@ -1861,13 +1856,13 @@ int main(int argc, char **argv)
 	}
 
 	if (cb_config.need_ish)
-		ctx.address_mode = ADDRESS_MODE_2_REL_TAB;
+		ctx.address_mode = AMD_ADDR_REL_TAB;
 	else if (cb_config.second_gen)
-		ctx.address_mode = ADDRESS_MODE_1_REL_BIOS;
+		ctx.address_mode = AMD_ADDR_REL_BIOS;
 	else
-		ctx.address_mode = ADDRESS_MODE_0_PHY;
+		ctx.address_mode = AMD_ADDR_PHYSICAL;
 	printf("    AMDFWTOOL  Using firmware directory location of %s address: 0x%08x\n",
-			ctx.address_mode == ADDRESS_MODE_0_PHY ? "absolute" : "relative",
+			ctx.address_mode == AMD_ADDR_PHYSICAL ? "absolute" : "relative",
 			RUN_CURRENT(ctx));
 
 	integrate_firmwares(&ctx, amd_romsig, amd_fw_table);
diff --git a/util/amdfwtool/amdfwtool.h b/util/amdfwtool/amdfwtool.h
index 0bef43a6cd..d40e60d237 100644
--- a/util/amdfwtool/amdfwtool.h
+++ b/util/amdfwtool/amdfwtool.h
@@ -83,6 +83,13 @@ typedef enum _amd_bios_type {
 	AMD_BIOS_SKIP
 } amd_bios_type;
 
+typedef enum _amd_addr_mode {
+	AMD_ADDR_PHYSICAL = 0,	/* Physical address */
+	AMD_ADDR_REL_BIOS,	/* Relative to beginning of image */
+	AMD_ADDR_REL_TAB,	/* Relative to table */
+	AMD_ADDR_REL_SLOT,	/* Relative to slot */
+} amd_addr_mode;
+
 struct second_gen_efs { /* todo: expand for Server products */
 	int gen:1; /* Client products only use bit 0 */
 	int reserved:31;
@@ -293,5 +300,6 @@ uint8_t process_config(FILE *config, amd_cb_config *cb_config, uint8_t print_dep
 #define LINE_EOF (1)
 #define LINE_TOO_LONG (2)
 
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
 #endif	/* _AMD_FW_TOOL_H_ */
diff --git a/util/testing/Makefile.inc b/util/testing/Makefile.inc
index 5c9e4d85a9..5a81e3bf28 100644
--- a/util/testing/Makefile.inc
+++ b/util/testing/Makefile.inc
@@ -50,6 +50,7 @@ junit.xml:
 	echo
 
 TOOLLIST= \
+amdfwread \
 amdfwtool \
 cbfstool \
 cbmem \