hw/ip/rom_ctrl/data/rom_ctrl.hjson

// Copyright lowRISC contributors.
// Licensed under the Apache License, Version 2.0, see LICENSE for details.
// SPDX-License-Identifier: Apache-2.0
{
  name: "rom_ctrl"
  clocking: [{clock: "clk_i", reset: "rst_ni"}],
  regwidth: "32"
  bus_interfaces: [
    { protocol: "tlul", direction: "device", name: "regs" }
    { protocol: "tlul", direction: "device", name: "rom" },
  ],
  param_list: [
    { name:    "BootRomInitFile",
      type:    "",
      default: '""',
      desc:    "Contents of mask ROM"
      local:   "false",
      expose:  "true"
    }

    { name:      "RndCnstScrNonce",
      type:      "bit [63:0]",
      desc:      "Fixed nonce used for address / data scrambling"
      randcount: "64",
      randtype:  "data"
    }

    { name:      "RndCnstScrKey",
      type:      "bit [127:0]",
      desc:      "Randomised constant used as a scrambling key for ROM data"
      randcount: "128",
      randtype:  "data"
    }
  ]
  alert_list: [
    { name: "fatal"
      desc: "A fatal error. Fatal alerts are non-recoverable and will be asserted until a hard reset."
    }
  ],
  inter_signal_list: [
    // Interface to memory configuration
    { name:    "rom_cfg",
      package: "prim_rom_pkg",
      struct:  "rom_cfg",
      act:     "rcv"
      type:    "uni",
    },

    // Power manager interface
    { name:    "pwrmgr_data"
      package: "rom_ctrl_pkg"
      struct:  "pwrmgr_data"
      act:     "req"
      type:    "uni"
    },

    // Keymgr interface
    { name:    "keymgr_data"
      package: "rom_ctrl_pkg"
      struct:  "keymgr_data"
      act:     "req"
      type:    "uni"
    },

    // KMAC interface
    { name:    "kmac_data"
      package: "kmac_pkg"
      struct:  "app"
      act:     "req"
      type:    "req_rsp"
    },
  ],
  regwidth: "32"
  registers: {
    regs: [
      { name: "FATAL_ALERT_CAUSE",
        desc: '''
          The cause of a fatal alert.

          The bits of this register correspond to errors that can cause a fatal
          alert. Software can read these bits to see what went wrong. Once set,
          these bits cannot be cleared.
        '''
        swaccess: "ro",
        hwaccess: "hwo",
        fields: [
          { bits: "0",
            name: "checker_error",
            resval: 0,
            desc: "Set on a fatal error detected by the ROM checker."
          }
          { bits: "1",
            name: "integrity_error",
            resval: 0,
            desc: "Set on an integrity error from the register interface."
          }
        ]
      }

      {
        multireg: {
          cname: "ROM_CTRL",
          name: "DIGEST",
          desc: "The digest computed from the contents of ROM"
          count: "8"
          swaccess: "ro"
          hwaccess: "hrw"
          fields: [
            {
              bits: "31:0"
              name: "DIGEST"
              desc: "32 bits of the digest"
            }
          ]
          // Disable CSR checks for digest registers, since their values will
          // change under the feet of the CSR package as the ROM checker computes
          // a digest. These values are checked instead by the rom_ctrl TB.
          tags: ["excl:CsrAllTests:CsrExclCheck"]
        }
      }
      {
        multireg: {
          cname: "ROM_CTRL",
          name: "EXP_DIGEST",
          desc: "The expected digest, stored in the top words of ROM"
          count: "8"
          swaccess: "ro"
          hwaccess: "hrw"
          fields: [
            {
              bits: "31:0"
              name: "DIGEST"
              desc: "32 bits of the digest"
            }
          ]
          // As with DIGEST, these values are checked by the rom_ctrl TB.
          tags: ["excl:CsrAllTests:CsrExclCheck"]
        }
      }
    ],

    rom: [
      // ROM size (given as `items` below) must be a power of two.
      //
      // NOTE: This number is replicated in ../util/scramble_image.py: keep the
      // two in sync.
      { window: {
          name: "ROM"
          items: "4096" // 16 KiB
          swaccess: "ro",
          desc: '''ROM data'''
        }
      }
    ]
  }
}