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
32 #include "hw/char/serial.h"
33 #include "hw/boards.h"
34 #include "exec/memory.h"
35 #include "exec/address-spaces.h"
36 #include "qemu/config-file.h"
37
38 #include "boot.h"
39
40 #define BINARY_DEVICE_TREE_FILE "generic-nommu.dtb"
41
nios2_generic_nommu_init(MachineState * machine)42 static void nios2_generic_nommu_init(MachineState *machine)
43 {
44 Nios2CPU *cpu;
45 MemoryRegion *address_space_mem = get_system_memory();
46 MemoryRegion *phys_tcm = g_new(MemoryRegion, 1);
47 MemoryRegion *phys_tcm_alias = g_new(MemoryRegion, 1);
48 MemoryRegion *phys_ram = g_new(MemoryRegion, 1);
49 MemoryRegion *phys_ram_alias = g_new(MemoryRegion, 1);
50 ram_addr_t tcm_base = 0x0;
51 ram_addr_t tcm_size = 0x1000; /* 1 kiB, but QEMU limit is 4 kiB */
52 ram_addr_t ram_base = 0x10000000;
53 ram_addr_t ram_size = 0x08000000;
54
55 /* Physical TCM (tb_ram_1k) with alias at 0xc0000000 */
56 memory_region_init_ram(phys_tcm, NULL, "nios2.tcm", tcm_size,
57 &error_abort);
58 memory_region_init_alias(phys_tcm_alias, NULL, "nios2.tcm.alias",
59 phys_tcm, 0, tcm_size);
60 memory_region_add_subregion(address_space_mem, tcm_base, phys_tcm);
61 memory_region_add_subregion(address_space_mem, 0xc0000000 + tcm_base,
62 phys_tcm_alias);
63
64 /* Physical DRAM with alias at 0xc0000000 */
65 memory_region_init_ram(phys_ram, NULL, "nios2.ram", ram_size,
66 &error_abort);
67 memory_region_init_alias(phys_ram_alias, NULL, "nios2.ram.alias",
68 phys_ram, 0, ram_size);
69 memory_region_add_subregion(address_space_mem, ram_base, phys_ram);
70 memory_region_add_subregion(address_space_mem, 0xc0000000 + ram_base,
71 phys_ram_alias);
72
73 cpu = NIOS2_CPU(cpu_create(TYPE_NIOS2_CPU));
74
75 /* Remove MMU */
76 cpu->mmu_present = false;
77
78 /* Reset vector is the first 32 bytes of RAM. */
79 cpu->reset_addr = ram_base;
80
81 /* The interrupt vector comes right after reset. */
82 cpu->exception_addr = ram_base + 0x20;
83
84 /*
85 * The linker script does have a TLB miss memory region declared,
86 * but this should never be used with no MMU.
87 */
88 cpu->fast_tlb_miss_addr = 0x7fff400;
89
90 nios2_load_kernel(cpu, ram_base, ram_size, machine->initrd_filename,
91 BINARY_DEVICE_TREE_FILE, NULL);
92 }
93
nios2_generic_nommu_machine_init(struct MachineClass * mc)94 static void nios2_generic_nommu_machine_init(struct MachineClass *mc)
95 {
96 mc->desc = "Generic NOMMU Nios II design";
97 mc->init = nios2_generic_nommu_init;
98 mc->deprecation_reason = "Nios II architecture is deprecated";
99 }
100
101 DEFINE_MACHINE("nios2-generic-nommu", nios2_generic_nommu_machine_init);
102