qemu

FORK: QEMU emulator
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imx7_snvs.c (2282B)

      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/module.h"
     18 #include "sysemu/runstate.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)