1/*
2 * Generic simulator target with no MMU or devices. This emulation is
3 * compatible with the libgloss qemu-hosted.ld linker script for using
4 * QEMU as an instruction set simulator.
5 *
6 * Copyright (c) 2018-2019 Mentor Graphics
7 *
8 * Copyright (c) 2016 Marek Vasut <marek.vasut@gmail.com>
9 *
10 * Based on LabX device code
11 *
12 * Copyright (c) 2012 Chris Wulff <crwulff@gmail.com>
13 *
14 * This library is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU Lesser General Public
16 * License as published by the Free Software Foundation; either
17 * version 2.1 of the License, or (at your option) any later version.
18 *
19 * This library is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * Lesser General Public License for more details.
23 *
24 * You should have received a copy of the GNU Lesser General Public
25 * License along with this library; if not, see
26 * <http://www.gnu.org/licenses/lgpl-2.1.html>
27 */
28
29#include "qemu/osdep.h"
30#include "qapi/error.h"
31#include "qemu-common.h"
32#include "cpu.h"
33
34#include "hw/sysbus.h"
35#include "hw/char/serial.h"
36#include "hw/boards.h"
37#include "exec/memory.h"
38#include "exec/address-spaces.h"
39#include "qemu/config-file.h"
40
41#include "boot.h"
42
43#define BINARY_DEVICE_TREE_FILE "generic-nommu.dtb"
44
45static void nios2_generic_nommu_init(MachineState *machine)
46{
47 Nios2CPU *cpu;
48 MemoryRegion *address_space_mem = get_system_memory();
49 MemoryRegion *phys_tcm = g_new(MemoryRegion, 1);
50 MemoryRegion *phys_tcm_alias = g_new(MemoryRegion, 1);
51 MemoryRegion *phys_ram = g_new(MemoryRegion, 1);
52 MemoryRegion *phys_ram_alias = g_new(MemoryRegion, 1);
53 ram_addr_t tcm_base = 0x0;
54 ram_addr_t tcm_size = 0x1000; /* 1 kiB, but QEMU limit is 4 kiB */
55 ram_addr_t ram_base = 0x10000000;
56 ram_addr_t ram_size = 0x08000000;
57
58 /* Physical TCM (tb_ram_1k) with alias at 0xc0000000 */
59 memory_region_init_ram(phys_tcm, NULL, "nios2.tcm", tcm_size,
60 &error_abort);
61 memory_region_init_alias(phys_tcm_alias, NULL, "nios2.tcm.alias",
62 phys_tcm, 0, tcm_size);
63 memory_region_add_subregion(address_space_mem, tcm_base, phys_tcm);
64 memory_region_add_subregion(address_space_mem, 0xc0000000 + tcm_base,
65 phys_tcm_alias);
66
67 /* Physical DRAM with alias at 0xc0000000 */
68 memory_region_init_ram(phys_ram, NULL, "nios2.ram", ram_size,
69 &error_abort);
70 memory_region_init_alias(phys_ram_alias, NULL, "nios2.ram.alias",
71 phys_ram, 0, ram_size);
72 memory_region_add_subregion(address_space_mem, ram_base, phys_ram);
73 memory_region_add_subregion(address_space_mem, 0xc0000000 + ram_base,
74 phys_ram_alias);
75
76 cpu = NIOS2_CPU(cpu_create(TYPE_NIOS2_CPU));
77
78 /* Remove MMU */
79 cpu->mmu_present = false;
80
81 /* Reset vector is the first 32 bytes of RAM. */
82 cpu->reset_addr = ram_base;
83
84 /* The interrupt vector comes right after reset. */
85 cpu->exception_addr = ram_base + 0x20;
86
87 /*
88 * The linker script does have a TLB miss memory region declared,
89 * but this should never be used with no MMU.
90 */
91 cpu->fast_tlb_miss_addr = 0x7fff400;
92
93 nios2_load_kernel(cpu, ram_base, ram_size, machine->initrd_filename,
94 BINARY_DEVICE_TREE_FILE, NULL);
95}
96
97static void nios2_generic_nommu_machine_init(struct MachineClass *mc)
98{
99 mc->desc = "Generic NOMMU Nios II design";
100 mc->init = nios2_generic_nommu_init;
101}
102
103DEFINE_MACHINE("nios2-generic-nommu", nios2_generic_nommu_machine_init);
104