qemu-e2k/hw/nios2/generic_nommu.c

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/*
* Generic simulator target with no MMU or devices. This emulation is
* compatible with the libgloss qemu-hosted.ld linker script for using
* QEMU as an instruction set simulator.
*
* Copyright (c) 2018-2019 Mentor Graphics
*
* Copyright (c) 2016 Marek Vasut <marek.vasut@gmail.com>
*
* Based on LabX device code
*
* Copyright (c) 2012 Chris Wulff <crwulff@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see
* <http://www.gnu.org/licenses/lgpl-2.1.html>
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "hw/char/serial.h"
#include "hw/boards.h"
#include "exec/memory.h"
#include "exec/address-spaces.h"
#include "qemu/config-file.h"
#include "boot.h"
#define BINARY_DEVICE_TREE_FILE "generic-nommu.dtb"
static void nios2_generic_nommu_init(MachineState *machine)
{
Nios2CPU *cpu;
MemoryRegion *address_space_mem = get_system_memory();
MemoryRegion *phys_tcm = g_new(MemoryRegion, 1);
MemoryRegion *phys_tcm_alias = g_new(MemoryRegion, 1);
MemoryRegion *phys_ram = g_new(MemoryRegion, 1);
MemoryRegion *phys_ram_alias = g_new(MemoryRegion, 1);
ram_addr_t tcm_base = 0x0;
ram_addr_t tcm_size = 0x1000; /* 1 kiB, but QEMU limit is 4 kiB */
ram_addr_t ram_base = 0x10000000;
ram_addr_t ram_size = 0x08000000;
/* Physical TCM (tb_ram_1k) with alias at 0xc0000000 */
memory_region_init_ram(phys_tcm, NULL, "nios2.tcm", tcm_size,
&error_abort);
memory_region_init_alias(phys_tcm_alias, NULL, "nios2.tcm.alias",
phys_tcm, 0, tcm_size);
memory_region_add_subregion(address_space_mem, tcm_base, phys_tcm);
memory_region_add_subregion(address_space_mem, 0xc0000000 + tcm_base,
phys_tcm_alias);
/* Physical DRAM with alias at 0xc0000000 */
memory_region_init_ram(phys_ram, NULL, "nios2.ram", ram_size,
&error_abort);
memory_region_init_alias(phys_ram_alias, NULL, "nios2.ram.alias",
phys_ram, 0, ram_size);
memory_region_add_subregion(address_space_mem, ram_base, phys_ram);
memory_region_add_subregion(address_space_mem, 0xc0000000 + ram_base,
phys_ram_alias);
cpu = NIOS2_CPU(cpu_create(TYPE_NIOS2_CPU));
/* Remove MMU */
cpu->mmu_present = false;
/* Reset vector is the first 32 bytes of RAM. */
cpu->reset_addr = ram_base;
/* The interrupt vector comes right after reset. */
cpu->exception_addr = ram_base + 0x20;
/*
* The linker script does have a TLB miss memory region declared,
* but this should never be used with no MMU.
*/
cpu->fast_tlb_miss_addr = 0x7fff400;
nios2_load_kernel(cpu, ram_base, ram_size, machine->initrd_filename,
BINARY_DEVICE_TREE_FILE, NULL);
}
static void nios2_generic_nommu_machine_init(struct MachineClass *mc)
{
mc->desc = "Generic NOMMU Nios II design";
mc->init = nios2_generic_nommu_init;
}
DEFINE_MACHINE("nios2-generic-nommu", nios2_generic_nommu_machine_init);