To access/read the lock bits, we use the same mode to read the chip id

This patch looks into the write situation for the Intel 28F001BX-{B,T}.
Looks like they're just a 82802ab page write.

Unlock_28f004s5 has been changed to read all the lock bits and if at
least one of the block lock bits are set, clear them all. If the master
lock bit is set, we can't do anything about it, so we return.

Corresponding to flashrom svn r965.

Signed-off-by: Sean Nelson <audiohacked@gmail.com>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>

1 files changed, 49 insertions, 0 deletions

diff --git a/82802ab.c b/82802ab.c
index 1316939..3aa76b4 100644
--- a/82802ab.c
+++ b/82802ab.c
@@ -205,3 +205,52 @@ int write_82802ab(struct flashchip *flash, uint8_t *buf)
 
 	return 0;
 }
+
+int unlock_28f004s5(struct flashrom *flash)
+{
+	chipaddr bios = flash->virtual_memory;
+	uint8_t mcfg, bcfg, need_unlock = 0, can_unlock = 0;
+
+	/* Clear status register */
+	chip_writeb(0x50, bios);
+
+	/* Read identifier codes */
+	chip_writeb(0x90, bios);
+
+	/* Read master lock-bit */
+	mcfg = chip_readb(bios + 0x3);
+	msg_cinfo("master lock is ");
+	if (mcfg) {
+		msg_cdbg("locked!\n");
+	} else {
+		msg_cdbg("unlocked!\n");
+		can_unlock = 1;
+	}
+	
+	/* Read block lock-bits */
+	for (i = 0; i < flash->total_size * 1024; i+= (64 * 1024)) {
+		bcfg = chip_readb(bios + i + 2); // read block lock config
+		msg_cdbg("block lock at %06x is %slocked!\n", i, bcfg ? "" : "un");
+		if (bcfg) {
+			need_unlock = 1;
+		}
+	}
+
+	/* Reset chip */
+	chip_writeb(0xFF, bios);
+
+	/* Unlock: clear block lock-bits, if needed */
+	if (can_unlock && need_unlock) {
+		chip_writeb(0x60, bios);
+		chip_writeb(0xD0, bios);
+		chip_writeb(0xFF, bios);
+	}
+
+	/* Error: master locked or a block is locked */
+	if (!can_unlock && need_unlock) {
+		msg_cerr("At least one block is locked and lockdown is active!\n");
+		return -1;
+	}
+
+	return 0;
+}