Change in flashrom[master]: Add support for generic SPI RES matching.

[Nico Huber (Code Review)]

Hello Carl-Daniel Hailfinger,

I'd like you to do a code review. Please visit

https://review.coreboot.org/25114

to review the following change.

Change subject: Add support for generic SPI RES matching.
......................................................................

Add support for generic SPI RES matching.

Support generic 1-byte SPI RES matching (low match quality) and enable
read support by guessing the chip size from the ID.
Support generic 2-byte SPI RES matching (high match quality).

Change-Id: Ie82d57740ee620c03861d2ebe812490431f4fb34
Signed-off-by: Carl-Daniel Hailfinger 
Signed-off-by: Stefan Tauner 
---
M chipdrivers.h
M flashchips.c
M flashrom.c
M spi25.c
4 files changed, 84 insertions(+), 13 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/14/25114/1

diff --git a/chipdrivers.h b/chipdrivers.h
index 0c78b0d..5626db5 100644
--- a/chipdrivers.h
+++ b/chipdrivers.h
@@ -33,6 +33,7 @@
 int probe_spi_rems(struct flashctx *flash);
 int probe_spi_res1(struct flashctx *flash);
 int probe_spi_res2(struct flashctx *flash);
+int probe_spi_automagic_res1(struct flashctx *flash);
 int spi_write_enable(struct flashctx *flash);
 int spi_write_disable(struct flashctx *flash);
 int spi_block_erase_20(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
diff --git a/flashchips.c b/flashchips.c
index 789f17f..2a38ee6 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -9662,6 +9662,24 @@

{
    	.vendor		= "Generic",
+		.name		= "unknown SPI chip (RES1)",
+		.bustype	= BUS_SPI,
+		.manufacture_id	= GENERIC_MANUF_ID,
+		.model_id	= GENERIC_DEVICE_ID,
+		.total_size	= 0,
+		.page_size	= 256,
+		.tested		= TEST_BAD_PREW,
+		.probe		= probe_spi_automagic_res1,
+		.probe_timing	= TIMING_ZERO,
+		.block_erasers	= {},
+		.unlock		= spi_disable_blockprotect,
+		.write		= NULL,
+		.read		= spi_chip_read,
+		.voltage	= {},
+	},
+
+	{
+		.vendor		= "Generic",
    	.name		= "unknown SPI chip (REMS)",
    	.bustype	= BUS_SPI,
    	.manufacture_id	= GENERIC_MANUF_ID,
@@ -9673,5 +9691,18 @@
    	.write		= NULL,
    },

+	{
+		.vendor		= "Generic",
+		.name		= "unknown SPI chip (RES2)",
+		.bustype	= BUS_SPI,
+		.manufacture_id	= GENERIC_MANUF_ID,
+		.model_id	= GENERIC_DEVICE_ID,
+		.total_size	= 0,
+		.page_size	= 256,
+		.tested		= TEST_BAD_PREW,
+		.probe		= probe_spi_res2,
+		.write		= NULL,
+	},
+
    { NULL 	}
 };
diff --git a/flashrom.c b/flashrom.c
index 44a3eba..c39abf6 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -1029,7 +1029,9 @@
    	if (startchip == 0)
    		break;
    	/* Not the first flash chip detected on this bus, but not a generic match either. */
-		if ((flash->chip->model_id != GENERIC_DEVICE_ID) && (flash->chip->model_id != SFDP_DEVICE_ID))
+		if ((flash->chip->manufacture_id != GENERIC_MANUF_ID) &&
+		    (flash->chip->model_id != GENERIC_DEVICE_ID) &&
+		    (flash->chip->model_id != SFDP_DEVICE_ID))
    		break;
    	/* Not the first flash chip detected on this bus, and it's just a generic match. Ignore it. */
 notfound:
diff --git a/spi25.c b/spi25.c
index 914b821..7d9e948 100644
--- a/spi25.c
+++ b/spi25.c
@@ -232,6 +232,7 @@

int probe_spi_res1(struct flashctx *flash)
 {
+	const struct flashchip *chip = flash->chip;
    static const unsigned char allff[] = {0xff, 0xff, 0xff};
    static const unsigned char all00[] = {0x00, 0x00, 0x00};
    unsigned char readarr[3];
@@ -265,18 +266,23 @@

msg_cdbg("%s: id 0x%x\n", __func__, id2);

-	if (id2 != flash->chip->model_id)
-		return 0;
+	if (id2 == flash->chip->model_id) {
+		/* Print the status register to tell the user about possible write protection. */
+		spi_prettyprint_status_register(flash);

-	/* Print the status register to tell the
-	 * user about possible write protection.
-	 */
-	spi_prettyprint_status_register(flash);
-	return 1;
+		return 1;
+	}
+
+	/* Test if there is any device ID. */
+	if (GENERIC_MANUF_ID == chip->manufacture_id && id2 == chip->model_id)
+		return 1;
+
+	return 0;
 }

int probe_spi_res2(struct flashctx *flash)
 {
+	const struct flashchip *chip = flash->chip;
    unsigned char readarr[2];
    uint32_t id1, id2;

@@ -289,13 +295,44 @@

msg_cdbg("%s: id1 0x%x, id2 0x%x\n", __func__, id1, id2);

-	if (id1 != flash->chip->manufacture_id || id2 != flash->chip->model_id)
+	if (id1 == chip->manufacture_id && id2 == chip->model_id) {
+		/* Print the status register to tell the
+		 * user about possible write protection.
+		 */
+		spi_prettyprint_status_register(flash);
+
+		return 1;
+	}
+
+	/* Test if this is a pure vendor match. */
+	if (id1 == chip->manufacture_id && GENERIC_DEVICE_ID == chip->model_id)
+		return 1;
+
+	/* Test if there is any vendor ID and if this is indeed a two-byte RES. */
+	if (GENERIC_MANUF_ID == chip->manufacture_id && id1 != 0xff && id1 != id2)
+		return 1;
+
+	return 0;
+}
+
+int probe_spi_automagic_res1(struct flashctx *flash)
+{
+	unsigned char readarr[1];
+	unsigned int total_size;
+	uint32_t id1;
+
+	if (spi_res(flash, readarr, 1))
    	return 0;

-	/* Print the status register to tell the
-	 * user about possible write protection.
-	 */
-	spi_prettyprint_status_register(flash);
+	id1 = readarr[0];
+	msg_cdbg("%s: id1 0x%02x\n", __func__, id1);
+	if (id1 < 0x10 || id1 > 0x17) {
+		msg_cdbg("RES ID out of bounds!\n");
+		return 0;
+	}
+	total_size = (2 << id1) / 1024;
+	flash->chip->total_size = total_size;
+	flash->chip->tested = TEST_OK_PR | TEST_BAD_ERASE | TEST_BAD_WRITE;
    return 1;
 }