1 /* 2 * IMX7 Secure Non-Volatile Storage 3 * 4 * Copyright (c) 2018, Impinj, Inc. 5 * 6 * Author: Andrey Smirnov <andrew.smirnov@gmail.com> 7 * 8 * This work is licensed under the terms of the GNU GPL, version 2 or later. 9 * See the COPYING file in the top-level directory. 10 * 11 * Bare minimum emulation code needed to support being able to shut 12 * down linux guest gracefully. 13 */ 14 15 #include "qemu/osdep.h" 16 #include "hw/misc/imx7_snvs.h" 17 #include "qemu/log.h" 18 #include "sysemu/sysemu.h" 19 20 static uint64_t imx7_snvs_read(void *opaque, hwaddr offset, unsigned size) 21 { 22 return 0; 23 } 24 25 static void imx7_snvs_write(void *opaque, hwaddr offset, 26 uint64_t v, unsigned size) 27 { 28 const uint32_t value = v; 29 const uint32_t mask = SNVS_LPCR_TOP | SNVS_LPCR_DP_EN; 30 31 if (offset == SNVS_LPCR && ((value & mask) == mask)) { 32 qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN); 33 } 34 } 35 36 static const struct MemoryRegionOps imx7_snvs_ops = { 37 .read = imx7_snvs_read, 38 .write = imx7_snvs_write, 39 .endianness = DEVICE_NATIVE_ENDIAN, 40 .impl = { 41 /* 42 * Our device would not work correctly if the guest was doing 43 * unaligned access. This might not be a limitation on the real 44 * device but in practice there is no reason for a guest to access 45 * this device unaligned. 46 */ 47 .min_access_size = 4, 48 .max_access_size = 4, 49 .unaligned = false, 50 }, 51 }; 52 53 static void imx7_snvs_init(Object *obj) 54 { 55 SysBusDevice *sd = SYS_BUS_DEVICE(obj); 56 IMX7SNVSState *s = IMX7_SNVS(obj); 57 58 memory_region_init_io(&s->mmio, obj, &imx7_snvs_ops, s, 59 TYPE_IMX7_SNVS, 0x1000); 60 61 sysbus_init_mmio(sd, &s->mmio); 62 } 63 64 static void imx7_snvs_class_init(ObjectClass *klass, void *data) 65 { 66 DeviceClass *dc = DEVICE_CLASS(klass); 67 68 dc->desc = "i.MX7 Secure Non-Volatile Storage Module"; 69 } 70 71 static const TypeInfo imx7_snvs_info = { 72 .name = TYPE_IMX7_SNVS, 73 .parent = TYPE_SYS_BUS_DEVICE, 74 .instance_size = sizeof(IMX7SNVSState), 75 .instance_init = imx7_snvs_init, 76 .class_init = imx7_snvs_class_init, 77 }; 78 79 static void imx7_snvs_register_type(void) 80 { 81 type_register_static(&imx7_snvs_info); 82 } 83 type_init(imx7_snvs_register_type) 84