From ce2148d90db5f2071ea3a47eea1820d3e9665a79 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Iwanicki?= <michal.iwanicki@3mdeb.com>
Date: Thu, 23 Oct 2025 10:07:11 +0200
Subject: [PATCH] flashrom.c: move `can_change_target_regions` check below wp
 unlock
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

We should check if target regions are writable after trying to unlock
them, not before.

Tested on PC Engines APU4A:

```
$ ./flashrom -p internal -c W25Q64BV/W25Q64CV/W25Q64FV --wp-status
(...)
Protection range: start=0x00400000 length=0x00400000 (upper 1/2)
Protection mode: hardware
```

Before this PR trying to write wp protected region:

```
$ ./flashrom -p internal -c W25Q64BV/W25Q64CV/W25Q64FV -l \
    <(echo -e '00300000:00500000 wp\n') -i wp -w image.bin
```

Failed with:

```
cannot fully update wp region (0x300000..0x500000) due to chip's
write-protection
```

With this change:

```
Using region: "wp".
coreboot table found at 0x7ecc2000.
Found chipset "AMD FCH".
Enabling flash write... OK.
Found Winbond flash chip "W25Q64BV/W25Q64CV/W25Q64FV" (8192 kB, SPI)
mapped at physical address 0x00000000ff800000.
Reading old flash chip contents... done.
Updating flash chip contents... Region [0x00300000 - 0x00500000] is not
sector aligned! Extending end boundaries by 0x00000fff bytes,
from 0x00500000 -> 0x00500fff
Erase/write done from 300000 to 500fff
```

Change-Id: I403d0a715d8efc03bb3f34ee73d718cc9e2aad59
Signed-off-by: Michał Iwanicki <michal.iwanicki@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/89852
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
---
 flashrom.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/flashrom.c b/flashrom.c
index f6a5be802..3ee826d6b 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -1900,13 +1900,6 @@ int prepare_flash_access(struct flashctx *const flash,
 		return 1;
 	}
 
-	if ((write_it || erase_it) && !flash->flags.force) {
-		if (!can_change_target_regions(flash)) {
-			msg_cerr("At least one target region is not fully writable. Aborting.\n");
-			return 1;
-		}
-	}
-
 	if (map_flash(flash) != 0)
 		return 1;
 
@@ -1930,6 +1923,13 @@ int prepare_flash_access(struct flashctx *const flash,
 	if (ret && bp_func)
 		bp_func(flash);
 
+	if ((write_it || erase_it) && !flash->flags.force) {
+		if (!can_change_target_regions(flash)) {
+			msg_cerr("At least one target region is not fully writable. Aborting.\n");
+			return 1;
+		}
+	}
+
 	flash->address_high_byte = -1;
 	flash->in_4ba_mode = false;