SD card size constraint conceptually wrong
This bug has been copied automatically from: https://bugs.launchpad.net/qemu/+bug/1910586
Reported by '-' on 2021-01-07 :
The patch discussed here: https://www.mail-archive.com/qemu-devel@nongnu.org/msg720833.html introduces an artificial size constraint for SD cards that has no relation to reality. I'm trying to use an _actual_ **physical** SD card, and qemu tells me its size is "invalid". Something here appears to be conceptually wrong. -------------------------------------------------- # fdisk -l /dev/sdg Disk /dev/sdg: 14.84 GiB, 15931539456 bytes, 31116288 sectors Disk model: USB SD Reader Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x7a0c8bb0 Device Boot Start End Sectors Size Id Type /dev/sdg1 2048 524287 522240 255M c W95 FAT32 (LBA) /dev/sdg2 524288 31116287 30592000 14.6G 83 Linux # qemu-system-aarch64 -M raspi3 -m 1G -kernel vmlinuz-5.4.79-v8 -dtb bcm2837-rpi-3-b-plus.dtb -append console=ttyAMA0\ root=/dev/mmcblk0p2\ rw -nographic -serial mon:stdio -drive file=/dev/sdg,format=raw qemu-system-aarch64: Invalid SD card size: 14.8 GiB SD card size has to be a power of 2, e.g. 16 GiB. You can resize disk images with 'qemu-img resize <imagefile> <new-size>' (note that this will lose data if you make the image smaller than it currently is). -------------------------------------------------- The same invocation with a dump of the actual image resized to match qemu's odd expectations works fine. This is on QEMU 5.2.0, as evidenced by the following: -------------------------------------------------- # qemu-system-aarch64 -version QEMU emulator version 5.2.0 Copyright (c) 2003-2020 Fabrice Bellard and the QEMU Project developers -------------------------------------------------- Is there a simple workaround that disables this rather arbitrary constraint?