[Qemu-devel] [PATCH 7/9] NiosII: Add a config that is dynamically set up by a device tree file.

[crwulff@gmail.com]

From: Chris Wulff <crwulff@gmail.com>

Signed-off-by: Chris Wulff <crwulff@gmail.com>
---
 default-configs/nios2-linux-user.mak |    1 +
 default-configs/nios2-softmmu.mak    |    6 +
 hw/labx_nios2_devicetree.c           |  665 ++++++++++++++++++++++++++++++++++
 hw/nios2/Makefile.objs               |    6 +
 4 files changed, 678 insertions(+)
 create mode 100644 default-configs/nios2-linux-user.mak
 create mode 100644 default-configs/nios2-softmmu.mak
 create mode 100644 hw/labx_nios2_devicetree.c
 create mode 100644 hw/nios2/Makefile.objs

diff --git a/default-configs/nios2-linux-user.mak b/default-configs/nios2-linux-user.mak
new file mode 100644
index 0000000..5be3eb7
--- /dev/null
+++ b/default-configs/nios2-linux-user.mak
@@ -0,0 +1 @@
+# Default configuration for nios2-linux-user
diff --git a/default-configs/nios2-softmmu.mak b/default-configs/nios2-softmmu.mak
new file mode 100644
index 0000000..09f6046
--- /dev/null
+++ b/default-configs/nios2-softmmu.mak
@@ -0,0 +1,6 @@
+# Default configuration for nios2-softmmu
+
+CONFIG_PTIMER=y
+CONFIG_PFLASH_CFI01=y
+CONFIG_ALTERA=y
+CONFIG_LABX=y
diff --git a/hw/labx_nios2_devicetree.c b/hw/labx_nios2_devicetree.c
new file mode 100644
index 0000000..d91bd9b
--- /dev/null
+++ b/hw/labx_nios2_devicetree.c
@@ -0,0 +1,665 @@
+/*
+ * Flexible model of nios2 designs that use a device-tree to determine
+ * the hardware configuration.
+ *
+ * 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 "sysbus.h"
+#include "hw.h"
+#include "net.h"
+#include "flash.h"
+#include "sysemu.h"
+#include "devices.h"
+#include "boards.h"
+#include "device_tree.h"
+#include "nios2.h"
+#include "altera.h"
+#include "labx_devices.h"
+#include "loader.h"
+#include "elf.h"
+#include "blockdev.h"
+#include "exec-memory.h"
+
+#define LMB_BRAM_SIZE  (128 * 1024)
+
+static int sopc_device_probe(void *fdt, int node, int pass, uint32_t offset);
+
+static struct {
+    uint32_t bootstrap_pc;
+    uint32_t cmdline;
+    uint32_t initrd;
+    uint32_t fdt;
+} boot_info;
+
+/* Current ethernet device index for multiple network interfaces */
+static int eth_dev_index = -1;
+
+static void main_cpu_reset(void *opaque)
+{
+    Nios2CPU *cpu = opaque;
+    CPUNios2State *env = &cpu->env;
+
+    cpu_reset(CPU(cpu));
+
+    env->regs[R_ARG0] = boot_info.cmdline;
+    env->regs[R_ARG1] = boot_info.initrd;
+    env->regs[R_ARG2] = boot_info.fdt;
+    env->regs[R_PC]   = boot_info.bootstrap_pc;
+}
+
+#ifndef CONFIG_FDT
+#error "Device-tree support is required for this target to function"
+#endif
+
+static uint32_t fdt_get_int_from_array(void *fdt, int node,
+                                       const char *name, int index)
+{
+    int array_length;
+    const void *array = qemu_devtree_getprop_offset(fdt, node, name,
+                                                    &array_length);
+    if (index >= array_length) {
+        printf("fdt_get_int_from_array: requesting %s from node %d, "
+               "index %d out of range (%d max)\n",
+               name, node, index, array_length);
+        return 0;
+    } else {
+        return qemu_devtree_int_array_index(array, index);
+    }
+}
+
+#define BINARY_DEVICE_TREE_FILE "labx-nios2.dtb"
+static void *get_device_tree(int *fdt_size)
+{
+    char *path;
+    void *fdt;
+
+    /* Try the local "local.dtb" override.  */
+    fdt = load_device_tree("local.dtb", fdt_size);
+    if (!fdt) {
+        path = qemu_find_file(QEMU_FILE_TYPE_BIOS, BINARY_DEVICE_TREE_FILE);
+        if (path) {
+            fdt = load_device_tree(path, fdt_size);
+            g_free(path);
+        }
+    }
+
+    return fdt;
+}
+
+static int labx_load_device_tree(target_phys_addr_t addr,
+                                 uint32_t ramsize,
+                                 target_phys_addr_t initrd_base,
+                                 target_phys_addr_t initrd_size,
+                                 const char *kernel_cmdline)
+{
+    int fdt_size;
+    void *fdt;
+    int r;
+
+    fdt = get_device_tree(&fdt_size);
+
+    if (!fdt) {
+        return 0;
+    }
+
+    if (kernel_cmdline && strlen(kernel_cmdline)) {
+        r = qemu_devtree_setprop_string(fdt, "/chosen", "bootargs",
+                                        kernel_cmdline);
+        if (r < 0) {
+            fprintf(stderr, "couldn't set /chosen/bootargs\n");
+        }
+    }
+    cpu_physical_memory_write(addr, (void *)fdt, fdt_size);
+
+    return fdt_size;
+}
+
+static uint64_t translate_kernel_address(void *opaque, uint64_t addr)
+{
+    return addr - 0xC0000000LL;
+}
+
+static ram_addr_t get_dram_base(void *fdt)
+{
+    int root = qemu_devtree_node_offset(fdt, "/");
+    int memory = qemu_devtree_subnode_offset_namelen(fdt, root, "memory", 6);
+    if (memory > 0) {
+        int reglen;
+        const void *reg = qemu_devtree_getprop_offset(fdt, memory, "reg",
+                                                      &reglen);
+
+        if (reglen >= 4) {
+            printf("DRAM base %08X, size %08X\n",
+                qemu_devtree_int_array_index(reg, 0),
+                qemu_devtree_int_array_index(reg, 1));
+            return qemu_devtree_int_array_index(reg, 0);
+        }
+    }
+
+    printf("DRAM base not found. Defaulting to 0x00000000\n");
+
+    return 0x00000000; /* Default to something reasonable */
+}
+
+typedef void (*device_init_func_t)(void *fdt, int node, uint32_t offset);
+
+typedef struct {
+    device_init_func_t probe;
+    int pass;
+    const char **compat;
+
+} devinfo_t;
+
+/*
+ * Interrupt controller device
+ */
+Nios2CPU *g_cpu;
+static qemu_irq irq[32] = {};
+static qemu_irq *cpu_irq;
+
+static void cpu_probe(void *fdt, int node, uint32_t offset)
+{
+    int i;
+    DeviceState *dev;
+#if 0 /* TODO: Finish off the vectored-interrupt-controller */
+    int reglen;
+    const void *reg = qemu_devtree_getprop_offset(fdt, node, "reg", &reglen);
+    uint32_t irq_addr = qemu_devtree_int_array_index(reg, 0) + offset;
+    int nrIrqLen;
+    const void *nrIrq =
+        qemu_devtree_getprop_offset(fdt, node, "ALTR,num-intr-inputs",
+                                    &nrIrqLen);
+    uint32_t nrIrqs = qemu_devtree_int_array_index(nrIrq, 0);
+
+    printf("  IRQ BASE %08X NIRQS %d\n", irq_addr, nrIrqs);
+
+    cpu_irq = nios2_pic_init_cpu(env);
+    dev = altera_vic_create(irq_addr, cpu_irq[0], 2);
+#else
+    /* Internal interrupt controller (IIC) */
+    cpu_irq = nios2_pic_init_cpu(&g_cpu->env);
+    dev = altera_iic_create(cpu_irq[0], 2);
+#endif
+
+    /* TODO: use the entrypoint of the passed in elf file or
+       the device-tree one */
+#if 0
+    g_cpu->env.reset_addr =
+        fdt_get_int_from_array(fdt, node, "ALTR,reset-addr", 0);
+#else
+    g_cpu->env.reset_addr = 0xc0000000;
+#endif
+
+    g_cpu->env.exception_addr =
+        fdt_get_int_from_array(fdt, node, "ALTR,exception-addr", 0);
+    g_cpu->env.fast_tlb_miss_addr =
+        fdt_get_int_from_array(fdt, node, "ALTR,fast-tlb-miss-addr", 0);
+
+    /* reset again to use the new reset vector */
+    cpu_reset(CPU(g_cpu));
+
+    for (i = 0; i < 32; i++) {
+        irq[i] = qdev_get_gpio_in(dev, i);
+    }
+}
+
+devinfo_t cpu_device = {
+    .probe = &cpu_probe,
+    .pass = 0,
+    .compat = (const char * []) {
+        "ALTR,nios2-11.0",
+        "ALTR,nios2-11.1",
+        "ALTR,nios2-12.0",
+        NULL
+    }
+};
+
+/*
+ * Flash device
+ */
+static void flash_probe(void *fdt, int node, uint32_t offset)
+{
+    int reglen;
+    const void *reg = qemu_devtree_getprop_offset(fdt, node, "reg", &reglen);
+    uint32_t flash_addr = qemu_devtree_int_array_index(reg, 0) + offset;
+    uint32_t flash_size = qemu_devtree_int_array_index(reg, 1);
+
+    DriveInfo *dinfo = drive_get(IF_PFLASH, 0, 0);
+    pflash_cfi01_register(flash_addr, NULL,
+                          qemu_devtree_get_name(fdt, node, NULL), flash_size,
+                          dinfo ? dinfo->bdrv : NULL, (64 * 1024),
+                          flash_size >> 16,
+                          1, 0x89, 0x18, 0x0000, 0x0, 0);
+    printf("-- loaded %d bytes to %08X\n",
+           load_image_targphys(qemu_devtree_get_name(fdt, node, NULL),
+                               flash_addr, flash_size), flash_addr);
+}
+
+devinfo_t flash_device = {
+    .probe = &flash_probe,
+    .pass = 1,
+    .compat = (const char * []) { "cfi-flash", NULL }
+};
+
+/*
+ * LabX audio packetizer device
+ */
+static void labx_audio_packetizer_probe(void *fdt, int node, uint32_t offset)
+{
+    uint32_t packetizer_addr = fdt_get_int_from_array(fdt, node, "reg", 0) +
+                               offset;
+    uint32_t packetizer_irq =
+        fdt_get_int_from_array(fdt, node, "interrupts", 0);
+    uint32_t clock_domains =
+        fdt_get_int_from_array(fdt, node, "labx,num-clock-domains", 0);
+    uint32_t cache_words =
+        fdt_get_int_from_array(fdt, node, "labx,cache-data-words", 0);
+
+    labx_audio_packetizer_create(packetizer_addr, irq[packetizer_irq],
+                                 clock_domains, cache_words);
+}
+
+devinfo_t labx_audio_packetizer_device = {
+    .probe = &labx_audio_packetizer_probe,
+    .pass = 1,
+    .compat = (const char * []) { "labx,labx_audio_packetizer-1.0", NULL }
+};
+
+/*
+ * LabX audio depacketizer device
+ */
+static void labx_audio_depacketizer_probe(void *fdt, int node, uint32_t offset)
+{
+    uint32_t depacketizer_addr = fdt_get_int_from_array(fdt, node, "reg", 0) +
+                                 offset;
+    uint32_t depacketizer_irq =
+        fdt_get_int_from_array(fdt, node, "interrupts", 0);
+    uint32_t clock_domains =
+        fdt_get_int_from_array(fdt, node, "labx,num-clock-domains", 0);
+    uint32_t cache_words =
+        fdt_get_int_from_array(fdt, node, "labx,cache-data-words", 0);
+
+    int ifLen;
+    const void *ifType =
+        qemu_devtree_getprop_offset(fdt, node, "labx,interface-type", &ifLen);
+    int hasDMA = (0 != strncmp("CACHE_RAM", (const char *)ifType, ifLen));
+
+    labx_audio_depacketizer_create(depacketizer_addr, irq[depacketizer_irq],
+                                   clock_domains, cache_words, hasDMA);
+}
+
+devinfo_t labx_audio_depacketizer_device = {
+    .probe = &labx_audio_depacketizer_probe,
+    .pass = 1,
+    .compat = (const char * []) {
+        "labx,labx-audio-depacketizer-1.00.a",
+        "labx,labx-audio-depacketizer-1.01.a",
+        NULL
+    }
+};
+
+/*
+ * LabX dma device
+ */
+static void labx_dma_probe(void *fdt, int node, uint32_t offset)
+{
+    uint32_t dma_addr = fdt_get_int_from_array(fdt, node, "reg", 0) + offset;
+
+    labx_dma_create(dma_addr, 1024);
+}
+
+devinfo_t labx_dma_device = {
+    .probe = &labx_dma_probe,
+    .pass = 1,
+    .compat = (const char * []) { "labx,labx_dma-1.0", NULL }
+};
+
+/*
+ * LabX ethernet device
+ */
+static void labx_ethernet_probe(void *fdt, int node, uint32_t offset)
+{
+    uint32_t ethernet_addr = fdt_get_int_from_array(fdt, node, "reg", 0) +
+                             offset;
+    uint32_t host_irq =
+        fdt_get_int_from_array(fdt, node, "interrupts", 0);
+    uint32_t fifo_irq = 0; /*
+        fdt_get_int_from_array(fdt, node, "interrupts", 2); */
+    uint32_t phy_irq = 0; /*
+        fdt_get_int_from_array(fdt, node, "interrupts", 4); */
+
+    labx_ethernet_create(&nd_table[++eth_dev_index], ethernet_addr,
+                         irq[host_irq], irq[fifo_irq], irq[phy_irq]);
+}
+
+devinfo_t labx_ethernet_device = {
+    .probe = &labx_ethernet_probe,
+    .pass = 1,
+    .compat = (const char * []) { "labx,labx_ethernet-1.0", NULL }
+};
+
+/*
+ * LabX ptp device
+ */
+static void labx_ptp_probe(void *fdt, int node, uint32_t offset)
+{
+    uint32_t ptp_addr = fdt_get_int_from_array(fdt, node, "reg", 0) + offset;
+
+    labx_ptp_create(ptp_addr);
+}
+
+devinfo_t labx_ptp_device = {
+    .probe = &labx_ptp_probe,
+    .pass = 1,
+    .compat = (const char * []) { "labx,labx_ptp-1.0", NULL }
+};
+
+/*
+ * Altera uart device
+ */
+static void altera_uart_probe(void *fdt, int node, uint32_t offset)
+{
+    uint32_t uart_addr = fdt_get_int_from_array(fdt, node, "reg", 0) + offset;
+    uint32_t uart_irq = fdt_get_int_from_array(fdt, node, "interrupts", 0);
+
+    printf("  UART BASE %08X IRQ %d\n", uart_addr, uart_irq);
+
+    sysbus_create_simple("altera,uart", uart_addr, irq[uart_irq]);
+}
+
+devinfo_t altera_uart_device = {
+    .probe = &altera_uart_probe,
+    .pass = 1,
+    .compat = (const char * []) { "ALTR,uart-1.0", NULL }
+};
+
+/*
+ * Altera timer device
+ */
+static void altera_timer_probe(void *fdt, int node, uint32_t offset)
+{
+    uint32_t timer_addr = fdt_get_int_from_array(fdt, node, "reg", 0) + offset;
+    uint32_t timer_irq = fdt_get_int_from_array(fdt, node, "interrupts", 0);
+    uint32_t timer_freq =
+        fdt_get_int_from_array(fdt, node, "clock-frequency", 0);
+
+    printf("  TIMER BASE %08X IRQ %d FREQUENCY %d\n",
+           timer_addr, timer_irq, timer_freq);
+
+    altera_timer_create(timer_addr, irq[timer_irq], timer_freq);
+}
+
+devinfo_t altera_timer_device = {
+    .probe = &altera_timer_probe,
+    .pass = 1,
+    .compat = (const char * []) { "ALTR,timer-1.0", NULL }
+};
+
+/*
+ * Altera clock domain crossing bridge
+ */
+static void altera_bridge_probe(void *fdt, int node, uint32_t offset)
+{
+    uint32_t bridge_addr = fdt_get_int_from_array(fdt, node, "reg", 0) + offset;
+
+    printf("  BRIDGE %08X\n", bridge_addr);
+
+    /* Do multiple passes through the devices. Some have dependencies
+       on others being first */
+    int pass = 0;
+    int again = 0;
+    do {
+        int child = node;
+        again = 0;
+        do {
+            child = qemu_devtree_next_child_offset(fdt, node, child);
+            if (child < 0) {
+                break;
+            }
+
+            again |= sopc_device_probe(fdt, child, pass, bridge_addr);
+
+        } while (1);
+
+        pass++;
+
+    } while (again);
+}
+
+devinfo_t altera_bridge_device = {
+    .probe = &altera_bridge_probe,
+    .pass = 1,
+    .compat = (const char * []) { "simple-bus", NULL }
+};
+
+/*
+ * Table of available devices
+ */
+devinfo_t *devices[] = {
+    &cpu_device,
+    &flash_device,
+    &labx_audio_packetizer_device,
+    &labx_audio_depacketizer_device,
+    &labx_dma_device,
+    &labx_ethernet_device,
+    &labx_ptp_device,
+    &altera_uart_device,
+    &altera_timer_device,
+    &altera_bridge_device,
+    NULL
+};
+
+static int sopc_device_probe(void *fdt, int node, int pass, uint32_t offset)
+{
+    devinfo_t **dev = &(devices[0]);
+
+    while (*dev) {
+        const char **compat = &((*dev)->compat[0]);
+        while (*compat) {
+            if (0 == qemu_devtree_node_check_compatible(fdt, node, *compat)) {
+                if (pass == (*dev)->pass) {
+                    printf("Adding a device for node %s\n",
+                           qemu_devtree_get_name(fdt, node, NULL));
+
+                    (*dev)->probe(fdt, node, offset);
+                    return 0;
+                }
+
+                if (pass < (*dev)->pass) {
+                    /* Probe again on the next pass */
+                    return 1;
+                }
+            }
+
+            compat++;
+        }
+
+        dev++;
+    }
+
+    return 0;
+}
+
+static void cpus_probe(void *fdt)
+{
+    int root = qemu_devtree_node_offset(fdt, "/");
+    int cpus = qemu_devtree_subnode_offset_namelen(fdt, root, "cpus", 4);
+    if (cpus > 0) {
+        int child = cpus;
+        do {
+            child = qemu_devtree_next_child_offset(fdt, cpus, child);
+            if (child < 0) {
+                break;
+            }
+
+            sopc_device_probe(fdt, child, 0, 0xE0000000);
+        } while (1);
+    }
+}
+
+static void sopc_bus_probe(void *fdt)
+{
+    int root = qemu_devtree_node_offset(fdt, "/");
+    int sopc = qemu_devtree_subnode_offset_namelen(fdt, root, "sopc", 4);
+    if (sopc > 0) {
+        /* Do multiple passes through the devices. Some have dependencies
+           on others being first */
+        int pass = 0;
+        int again = 0;
+        do {
+            int child = sopc;
+            again = 0;
+            do {
+                child = qemu_devtree_next_child_offset(fdt, sopc, child);
+                if (child < 0) {
+                    break;
+                }
+
+                again |= sopc_device_probe(fdt, child, pass, 0xE0000000);
+
+            } while (1);
+
+            pass++;
+
+        } while (again);
+    }
+}
+
+static void
+labx_nios2_init(ram_addr_t ram_size,
+                const char *boot_device,
+                const char *kernel_filename,
+                const char *kernel_cmdline,
+                const char *initrd_filename,
+                const char *cpu_model)
+{
+    MemoryRegion *address_space_mem = get_system_memory();
+
+    int kernel_size;
+    int fdt_size;
+    void *fdt = get_device_tree(&fdt_size);
+    target_phys_addr_t ddr_base = get_dram_base(fdt);
+    MemoryRegion *phys_lmb_bram = g_new(MemoryRegion, 1);
+    MemoryRegion *phys_ram = g_new(MemoryRegion, 1);
+    MemoryRegion *phys_ram_alias = g_new(MemoryRegion, 1);
+
+    /* init CPUs */
+    if (cpu_model == NULL) {
+        cpu_model = "nios2";
+    }
+    g_cpu = cpu_nios2_init(cpu_model);
+
+    qemu_register_reset(main_cpu_reset, g_cpu);
+
+    /* Attach emulated BRAM through the LMB. LMB size is not specified
+       in the device-tree but there must be one to hold the vector table. */
+    memory_region_init_ram(phys_lmb_bram, "nios2.lmb_bram", LMB_BRAM_SIZE);
+    vmstate_register_ram_global(phys_lmb_bram);
+    memory_region_add_subregion(address_space_mem, 0x00000000, phys_lmb_bram);
+
+    memory_region_init_ram(phys_ram, "nios2.ram", ram_size);
+    vmstate_register_ram_global(phys_ram);
+    memory_region_add_subregion(address_space_mem, ddr_base, phys_ram);
+    memory_region_init_alias(phys_ram_alias, "nios2.ram.mirror",
+                             phys_ram, 0, ram_size);
+    memory_region_add_subregion(address_space_mem, ddr_base + 0xc0000000,
+                                phys_ram_alias);
+
+    /* Create cpus listed in the device-tree */
+    cpus_probe(fdt);
+
+    /* Create other devices listed in the device-tree */
+    sopc_bus_probe(fdt);
+
+    if (kernel_filename) {
+        uint64_t entry = 0, low = 0, high = 0;
+        uint32_t base32 = 0;
+
+        /* Boots a kernel elf binary.  */
+        kernel_size = load_elf(kernel_filename, NULL, NULL,
+                               &entry, &low, &high,
+                               0, ELF_MACHINE, 0);
+        base32 = entry;
+        if (base32 == 0xc0000000) {
+            kernel_size = load_elf(kernel_filename, translate_kernel_address,
+                                   NULL, &entry, NULL, NULL,
+                                   0, ELF_MACHINE, 0);
+        }
+        /* Always boot into physical ram.  */
+        boot_info.bootstrap_pc = ddr_base + 0xc0000000 + (entry & 0x07ffffff);
+
+        /* If it wasn't an ELF image, try an u-boot image.  */
+        if (kernel_size < 0) {
+            target_phys_addr_t uentry, loadaddr;
+
+            kernel_size = load_uimage(kernel_filename, &uentry, &loadaddr, 0);
+            boot_info.bootstrap_pc = uentry;
+            high = (loadaddr + kernel_size + 3) & ~3;
+        }
+
+        /* Not an ELF image nor an u-boot image, try a RAW image.  */
+        if (kernel_size < 0) {
+            kernel_size = load_image_targphys(kernel_filename, ddr_base,
+                                              ram_size);
+            boot_info.bootstrap_pc = ddr_base;
+            high = (ddr_base + kernel_size + 3) & ~3;
+        }
+
+        if (initrd_filename) {
+            uint32_t initrd_base = 0x88c00000;
+            uint32_t initrd_size =
+                load_image_targphys(initrd_filename, initrd_base,
+                                    ram_size - initrd_base);
+            if (initrd_size <= 0) {
+                fprintf(stderr, "qemu: could not load initial ram disk '%s'\n",
+                        initrd_filename);
+                exit(1);
+            }
+
+            boot_info.initrd = initrd_base;
+        } else {
+            boot_info.initrd = 0x00000000;
+        }
+
+        boot_info.cmdline = high + 4096;
+        if (kernel_cmdline && strlen(kernel_cmdline)) {
+            pstrcpy_targphys("cmdline", boot_info.cmdline, 256, kernel_cmdline);
+        }
+        /* Provide a device-tree.  */
+        boot_info.fdt = boot_info.cmdline + 4096;
+        labx_load_device_tree(boot_info.fdt, ram_size,
+                              0, 0,
+                              kernel_cmdline);
+    }
+}
+
+static QEMUMachine labx_nios2_machine = {
+    .name = "labx-nios2-devicetree",
+    .desc = "Nios II design based on the peripherals specified "
+            "in the device-tree.",
+    .init = labx_nios2_init,
+    .is_default = 1
+};
+
+static void labx_nios2_machine_init(void)
+{
+    qemu_register_machine(&labx_nios2_machine);
+}
+
+machine_init(labx_nios2_machine_init);
+
diff --git a/hw/nios2/Makefile.objs b/hw/nios2/Makefile.objs
new file mode 100644
index 0000000..33cdd9b
--- /dev/null
+++ b/hw/nios2/Makefile.objs
@@ -0,0 +1,6 @@
+obj-y  = labx_nios2_devicetree.o
+
+obj-y += nios2_pic_cpu.o
+obj-$(CONFIG_FDT) += ../device_tree.o
+
+obj-y := $(addprefix ../,$(obj-y))
-- 
1.7.9.5