Dear Dr. KC.Wang, Download qemu-4.2.0-rc4 source code, change hw/sd/sd.c at line 1560 like follows and remake
(line: 1560) if (req.arg & ACMD41_ENQUIRY_MASK) { /*if (FIELD_EX32(sd->ocr & req.arg, OCR, VDD_VOLTAGE_WINDOW)) {*/ BTW, here is my micro-kernel-os for arm platform based the contents from your books, thanks ! https://github.com/MisaZhu/micro_kernel_os Misa.Z -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1809291 Title: SD Card not working in Ubuntu 18.10 (CMD 2,3 timeout). The device worked fine in Ubuntu 18.04 and earlier versions but not in Ubuntu 18.10 Status in QEMU: Confirmed Bug description: ARM PL181 MMC card no longer working in qemu-system-arm in Ubuntu 18.10 The MMC driver code worked fine in Ubuntu 15.10 to 18.04. The command to run qemu-system-arm is qemu-system-arm -M versatilepb -m 256M -sd sdimage -kernel t.bin -serial mon:stdio During SDC initialization, SDC commands 2, 3, 9, 13, 7, 16 all timeout, which cause subsequent read/write commands 17/24 to fail also. Tried both ARM versatilepb and realview-pb-a8, realview-pbx-a9 boards: all the same. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1809291/+subscriptions