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authorStefan Tauner <stefan.tauner@alumni.tuwien.ac.at>2014-12-20 16:45:31 +0000
committerStefan Tauner <stefan.tauner@alumni.tuwien.ac.at>2014-12-20 16:45:31 +0000
commit1f795e4b3d20d8a9a558c1890b79a4c3ecab703c (patch)
tree16c9266af61435d7f2603998a3730ec7be1e09ed
parentec11c56e2398a7bdd699472fffc878572fa553fa (diff)
Fix handling of write protection at register space address +2
Since r1833 we added the offset of the virtual register in several functions, which produced segfaults. This patch renames a few parameters and reorganizes/fixes various parts of the changelock_regspace2_block() function - hence the rather big diff. Thanks to Roman Lebedev for reporting this issue and testing numerous revisions of this patch. Corresponding to flashrom svn r1859. Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at> Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
-rw-r--r--chipdrivers.h1
-rw-r--r--jedec.c93
2 files changed, 53 insertions, 41 deletions
diff --git a/chipdrivers.h b/chipdrivers.h
index 8529c74..cac94f3 100644
--- a/chipdrivers.h
+++ b/chipdrivers.h
@@ -150,7 +150,6 @@ int unlock_regspace2_uniform_32k(struct flashctx *flash);
int unlock_regspace2_uniform_64k(struct flashctx *flash);
int unlock_regspace2_block_eraser_0(struct flashctx *flash);
int unlock_regspace2_block_eraser_1(struct flashctx *flash);
-int unlock_regspace2_block(const struct flashctx *flash, chipaddr off);
int printlock_regspace2_uniform_64k(struct flashctx *flash);
int printlock_regspace2_block_eraser_0(struct flashctx *flash);
int printlock_regspace2_block_eraser_1(struct flashctx *flash);
diff --git a/jedec.c b/jedec.c
index 1345b89..19babf9 100644
--- a/jedec.c
+++ b/jedec.c
@@ -589,11 +589,10 @@ static int regspace2_walk_unlockblocks(const struct flashctx *flash, const struc
#define REG2_LOCKDOWN (1 << 1)
#define REG2_MASK (REG2_RWLOCK | REG2_LOCKDOWN)
-static int printlock_regspace2_block(const struct flashctx *flash, chipaddr offset)
+static int printlock_regspace2_block(const struct flashctx *flash, chipaddr lockreg)
{
- chipaddr wrprotect = flash->virtual_registers + offset + 2;
- uint8_t state = chip_readb(flash, wrprotect);
- msg_cdbg("Lock status of block at 0x%0*" PRIxPTR " is ", PRIxPTR_WIDTH, offset);
+ uint8_t state = chip_readb(flash, lockreg);
+ msg_cdbg("Lock status of block at 0x%0*" PRIxPTR " is ", PRIxPTR_WIDTH, lockreg);
switch (state & REG2_MASK) {
case 0:
msg_cdbg("Full Access.\n");
@@ -656,67 +655,81 @@ int printlock_regspace2_block_eraser_1(struct flashctx *flash)
return regspace2_walk_unlockblocks(flash, unlockblocks, &printlock_regspace2_block);
}
-static int changelock_regspace2_block(const struct flashctx *flash, chipaddr offset, uint8_t new_bits)
-{
- chipaddr wrprotect = flash->virtual_registers + offset + 2;
- uint8_t old;
-
- if (new_bits & ~REG2_MASK) {
- msg_cerr("Invalid locking change 0x%02x requested at 0x%0*" PRIxPTR "! "
+/* Try to change the lock register at address lockreg from cur to new.
+ *
+ * - Try to unlock the lock bit if requested and it is currently set (although this is probably futile).
+ * - Try to change the read/write bits if requested.
+ * - Try to set the lockdown bit if requested.
+ * Return an error immediately if any of this fails. */
+static int changelock_regspace2_block(const struct flashctx *flash, chipaddr lockreg, uint8_t cur, uint8_t new)
+{
+ /* Only allow changes to known read/write/lockdown bits */
+ if (((cur ^ new) & ~REG2_MASK) != 0) {
+ msg_cerr("Invalid lock change from 0x%02x to 0x%02x requested at 0x%0*" PRIxPTR "!\n"
"Please report a bug at flashrom@flashrom.org\n",
- new_bits, PRIxPTR_WIDTH, offset);
+ cur, new, PRIxPTR_WIDTH, lockreg);
return -1;
}
- old = chip_readb(flash, wrprotect);
- /* Early exist if no change (of read/write/lockdown) was requested. */
- if (((old ^ new_bits) & REG2_MASK) == 0) {
- msg_cdbg2("Locking status at 0x%0*" PRIxPTR " not changed\n", PRIxPTR_WIDTH, offset);
+
+ /* Exit early if no change (of read/write/lockdown bits) was requested. */
+ if (((cur ^ new) & REG2_MASK) == 0) {
+ msg_cdbg2("Lock bits at 0x%0*" PRIxPTR " not changed.\n", PRIxPTR_WIDTH, lockreg);
return 0;
}
- /* Normally lockdowns can not be cleared. Try nevertheless if requested. */
- if ((old & REG2_LOCKDOWN) && !(new_bits & REG2_LOCKDOWN)) {
- chip_writeb(flash, old & ~REG2_LOCKDOWN, wrprotect);
- if (chip_readb(flash, wrprotect) != (old & ~REG2_LOCKDOWN)) {
- msg_cerr("Lockdown can't be removed at 0x%0*" PRIxPTR "!\n", PRIxPTR_WIDTH, offset);
+
+ /* Normally the lockdown bit can not be cleared. Try nevertheless if requested. */
+ if ((cur & REG2_LOCKDOWN) && !(new & REG2_LOCKDOWN)) {
+ chip_writeb(flash, cur & ~REG2_LOCKDOWN, lockreg);
+ cur = chip_readb(flash, lockreg);
+ if ((cur & REG2_LOCKDOWN) == REG2_LOCKDOWN) {
+ msg_cwarn("Lockdown can't be removed at 0x%0*" PRIxPTR "! New value: 0x%02x.\n",
+ PRIxPTR_WIDTH, lockreg, cur);
return -1;
}
}
- /* Change read or write lock? */
- if ((old ^ new_bits) & REG2_RWLOCK) {
+
+ /* Change read and/or write bit */
+ if ((cur ^ new) & REG2_RWLOCK) {
/* Do not lockdown yet. */
- msg_cdbg("Changing locking status at 0x%0*" PRIxPTR " to 0x%02x\n", PRIxPTR_WIDTH, offset, new_bits & REG2_RWLOCK);
- chip_writeb(flash, new_bits & REG2_RWLOCK, wrprotect);
- if (chip_readb(flash, wrprotect) != (new_bits & REG2_RWLOCK)) {
- msg_cerr("Locking status change FAILED at 0x%0*" PRIxPTR "!\n", PRIxPTR_WIDTH, offset);
+ uint8_t wanted = (cur & ~REG2_RWLOCK) | (new & REG2_RWLOCK);
+ chip_writeb(flash, wanted, lockreg);
+ cur = chip_readb(flash, lockreg);
+ if (cur != wanted) {
+ msg_cerr("Changing lock bits failed at 0x%0*" PRIxPTR "! New value: 0x%02x.\n",
+ PRIxPTR_WIDTH, lockreg, cur);
return -1;
}
+ msg_cdbg("Changed lock bits at 0x%0*" PRIxPTR " to 0x%02x.\n",
+ PRIxPTR_WIDTH, lockreg, cur);
}
- /* Enable lockdown if requested. */
- if (!(old & REG2_LOCKDOWN) && (new_bits & REG2_LOCKDOWN)) {
- msg_cdbg("Enabling lockdown at 0x%0*" PRIxPTR "\n", PRIxPTR_WIDTH, offset);
- chip_writeb(flash, new_bits, wrprotect);
- if (chip_readb(flash, wrprotect) != new_bits) {
- msg_cerr("Enabling lockdown FAILED at 0x%0*" PRIxPTR "!\n", PRIxPTR_WIDTH, offset);
+
+ /* Eventually, enable lockdown if requested. */
+ if (!(cur & REG2_LOCKDOWN) && (new & REG2_LOCKDOWN)) {
+ chip_writeb(flash, new, lockreg);
+ cur = chip_readb(flash, lockreg);
+ if (cur != new) {
+ msg_cerr("Enabling lockdown FAILED at 0x%0*" PRIxPTR "! New value: 0x%02x.\n",
+ PRIxPTR_WIDTH, lockreg, cur);
return -1;
}
+ msg_cdbg("Enabled lockdown at 0x%0*" PRIxPTR ".\n", PRIxPTR_WIDTH, lockreg);
}
return 0;
}
-int unlock_regspace2_block(const struct flashctx *flash, chipaddr off)
+static int unlock_regspace2_block_generic(const struct flashctx *flash, chipaddr lockreg)
{
- chipaddr wrprotect = flash->virtual_registers + off + 2;
- uint8_t old = chip_readb(flash, wrprotect);
+ uint8_t old = chip_readb(flash, lockreg);
/* We don't care for the lockdown bit as long as the RW locks are 0 after we're done */
- return changelock_regspace2_block(flash, off, old & ~REG2_RWLOCK);
+ return changelock_regspace2_block(flash, lockreg, old, old & ~REG2_RWLOCK);
}
static int unlock_regspace2_uniform(struct flashctx *flash, unsigned long block_size)
{
const unsigned int elems = flash->chip->total_size * 1024 / block_size;
struct unlockblock blocks[2] = {{.size = block_size, .count = elems}};
- return regspace2_walk_unlockblocks(flash, blocks, &unlock_regspace2_block);
+ return regspace2_walk_unlockblocks(flash, blocks, &unlock_regspace2_block_generic);
}
int unlock_regspace2_uniform_64k(struct flashctx *flash)
@@ -734,7 +747,7 @@ int unlock_regspace2_block_eraser_0(struct flashctx *flash)
// FIXME: this depends on the eraseblocks not to be filled up completely (i.e. to be null-terminated).
const struct unlockblock *unlockblocks =
(const struct unlockblock *)flash->chip->block_erasers[0].eraseblocks;
- return regspace2_walk_unlockblocks(flash, unlockblocks, &unlock_regspace2_block);
+ return regspace2_walk_unlockblocks(flash, unlockblocks, &unlock_regspace2_block_generic);
}
int unlock_regspace2_block_eraser_1(struct flashctx *flash)
@@ -742,6 +755,6 @@ int unlock_regspace2_block_eraser_1(struct flashctx *flash)
// FIXME: this depends on the eraseblocks not to be filled up completely (i.e. to be null-terminated).
const struct unlockblock *unlockblocks =
(const struct unlockblock *)flash->chip->block_erasers[1].eraseblocks;
- return regspace2_walk_unlockblocks(flash, unlockblocks, &unlock_regspace2_block);
+ return regspace2_walk_unlockblocks(flash, unlockblocks, &unlock_regspace2_block_generic);
}