generic_nommu.c (3679B)
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 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 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 } 99 100 DEFINE_MACHINE("nios2-generic-nommu", nios2_generic_nommu_machine_init);