cr50: add rollback information to the sysinfo command output

With enabling INFO1 map based rollback protection it is important to
be able to tell the state of the flash map and the currently installed
images' infomap header field.

The new function counts number of zero words in the info map and zero
bits in both RW headers, and returns them in a string printed out by
the sysinfo command.

BRANCH=cr50
BUG=b:35774863
TEST=built images with different manifest info field contents and
     verified that the string printed by the sysinfo command makes sense.

Change-Id: If633a6c678dc34197b2dad116b6180b2d549e089
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/450905
Reviewed-by: Nagendra Modadugu <ngm@google.com>
Reviewed-by: Mary Ruthven <mruthven@chromium.org>

1 files changed, 40 insertions, 0 deletions

diff --git a/chip/g/system.c b/chip/g/system.c
index c9dc325688..e92899a58c 100644
--- a/chip/g/system.c
+++ b/chip/g/system.c
@@ -621,3 +621,43 @@ void system_update_rollback_mask(void)
 	ccprintf("updated %d info map words\n", updated_words_count);
 #endif  /*  CR50_DEV ^^^^^^^^ NOT defined. */
 }
+
+void system_get_rollback_bits(char *value, size_t value_size)
+{
+	int info_count;
+	int i;
+	struct {
+		int count;
+		const struct SignedHeader *h;
+	} headers[] = {
+		{.h = (const struct SignedHeader *)
+		 get_program_memory_addr(SYSTEM_IMAGE_RW)},
+
+		{.h = (const struct SignedHeader *)
+		 get_program_memory_addr(SYSTEM_IMAGE_RW_B)},
+	};
+
+	flash_info_read_enable(INFO_RW_MAP_OFFSET, INFO_RW_MAP_SIZE);
+	for (i = 0; i < INFO_MAX; i++) {
+		uint32_t w;
+
+		flash_physical_info_read_word(INFO_RW_MAP_OFFSET +
+					      i * sizeof(uint32_t),
+					      &w);
+		if (w)
+			break;
+	}
+	info_count = i;
+
+	for (i = 0; i < ARRAY_SIZE(headers); i++) {
+		int j;
+
+		for (j = 0; j < INFO_MAX; j++)
+			if (headers[i].h->infomap[j/32] & (1 << (j%32)))
+				break;
+		headers[i].count = j;
+	}
+
+	snprintf(value, value_size, "%d/%d/%d", info_count,
+		 headers[0].count, headers[1].count);
+}