# Any way to disable SPI reads from flash? **URL:** \ **Category:** Router\ **Created:** [December 25, 2015, 12:53pm UTC](https://forum.gl-inet.com/t/any-way-to-disable-spi-reads-from-flash/1270 "2015-12-25T12:53:40Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![lbattraw](https://forum-assets.gl-inet.com/letter_avatar_proxy/v4/letter/l/e47c2d/32.png) [@lbattraw](https://forum.gl-inet.com/u/lbattraw)\ **Post date:** [December 25, 2015, 12:53pm UTC](https://forum.gl-inet.com/t/any-way-to-disable-spi-reads-from-flash/1270/1 "2015-12-25T12:53:40Z")
Hi, I’ve been trying to find a way to take advantage of more of the GPIO pins and have run into problems disabling the SPI flash. I am running from a SD card using extroot but I can’t find a way to make the kernel understand that it needs to access the SD card, not the SPI flash. As soon as I unmap the GPIOs used for SPI (By echoing the device to unmap to the unmap “file” in /sys) I start seeing errors about failures to read from the SPI flash device, which generally causes a kernel panic. I’ve tried unmounting the squashfs device beforehand or mounting the SD card over that device (The SD card has a full copy of the system), but it never seems to work. I’m guessing this is due to the way the read-only flash filesystem is overlaid onto the active FS on the SD card but I haven’t found a way to remove or replace that mapping once the overlay is set up. Any ideas? -Larry ---
**Author:** ![bruce](https://forum-assets.gl-inet.com/user_avatar/forum.gl-inet.com/bruce/32/35649_2.png) [@bruce](https://forum.gl-inet.com/u/bruce)\ **Post date:** [October 29, 2025, 2:34am UTC](https://forum.gl-inet.com/t/any-way-to-disable-spi-reads-from-flash/1270/2 "2025-10-29T02:34:55Z")