From: Michael <[email protected]> Introduce the 'neorv32' board wiring IMEM/DMEM/BOOTROM, SYSINFO, UART0, and SPI0; add docs/system/riscv/neorv32.rst and riscv32-softmmu device config entry.
Signed-off-by: Michael Levit <[email protected]> --- configs/devices/riscv32-softmmu/default.mak | 1 + docs/system/riscv/neorv32.rst | 112 ++++++++++ docs/system/target-riscv.rst | 1 + hw/riscv/Kconfig | 8 + hw/riscv/meson.build | 1 + hw/riscv/neorv32.c | 215 ++++++++++++++++++++ include/hw/riscv/neorv32.h | 54 +++++ 7 files changed, 392 insertions(+) create mode 100644 docs/system/riscv/neorv32.rst create mode 100644 hw/riscv/neorv32.c create mode 100644 include/hw/riscv/neorv32.h diff --git a/configs/devices/riscv32-softmmu/default.mak b/configs/devices/riscv32-softmmu/default.mak index c2cd86ce05..4fdc94ab48 100644 --- a/configs/devices/riscv32-softmmu/default.mak +++ b/configs/devices/riscv32-softmmu/default.mak @@ -10,3 +10,4 @@ # CONFIG_SIFIVE_U=n # CONFIG_RISCV_VIRT=n # CONFIG_OPENTITAN=n +# CONFIG_NEORV32=n diff --git a/docs/system/riscv/neorv32.rst b/docs/system/riscv/neorv32.rst new file mode 100644 index 0000000000..93ea751b1e --- /dev/null +++ b/docs/system/riscv/neorv32.rst @@ -0,0 +1,112 @@ + +NEORV32 Soft SoC (``neorv32``) +============================== + +The ``neorv32`` machine models a minimal NEORV32-based SoC sufficient to +exercise the stock NEORV32 bootloader and run example applications from an +emulated SPI NOR flash. It exposes a UART for console I/O and an MTD-backed +SPI flash device that can be populated with user binaries. + +Neorv32 full repo: +https://github.com/stnolting/neorv32 + +Current QEMU implementation base on commit 7d0ef6b2 in Neorv32 repo. + +Supported devices +----------------- + +The ``neorv32`` machine provides the core peripherals needed by the +bootloader and examples: + +* UART for console (mapped to the QEMU stdio when ``-nographic`` or + ``-serial stdio`` is used). +* SPI controller connected to an emulated SPI NOR flash (exposed to the + guest via QEMU's ``if=mtd`` backend). +* Basic timer/CLINT-like facilities required by the example software. + +(Exact register maps and optional peripherals depend on the QEMU version and +the specific patch series you are using.) + + +QEMU build configuration: +------------------------- + +From the command line:: + + $ /path/to/qemu/configure \ + --python=/usr/local/bin/python3.12 \ + --target-list=riscv32-softmmu \ + --enable-fdt \ + --enable-debug \ + --disable-vnc \ + --disable-gtk + +Boot options +------------ + +Typical usage is to boot the NEORV32 bootloader as the QEMU ``-bios`` image, +and to provide a raw SPI flash image via an MTD drive. The bootloader will +then jump to the application image placed at the configured flash offset. + +Preparing the SPI flash with a “Hello World” example +---------------------------------------------------- + +1. Create a 64 MiB flash image (filled with zeros):: + + $ dd if=/dev/zero of=$HOME/flash_contents.bin bs=1 count=$((0x04000000)) + +2. Place your application binary at the **4 MiB** offset inside the flash. + Replace ``/path/to/neorv32_exe.bin`` with the path to your compiled + example application (e.g., the NEORV32 ``hello_world`` example):: + + $ dd if=/path/to/neorv32_exe.bin of=$HOME/flash_contents.bin bs=1 seek=$((0x00400000)) conv=notrunc + +Running the “Hello World” example +--------------------------------- + +Run QEMU with the NEORV32 bootloader as ``-bios`` and attach the prepared +flash image via the MTD interface. Replace the placeholder paths with your +local paths:: + + $ /path/to/qemu-system-riscv32 -nographic -machine neorv32 \ + -bios /path/to/neorv32/bootloader/neorv32_raw_exe.bin \ + -drive file=$HOME/flash_contents.bin,if=mtd,format=raw + +Notes: + +* ``-nographic`` routes the UART to your terminal (Ctrl-A X to quit when + using the QEMU monitor hotkeys; or just close the terminal). +* The bootloader starts first and will transfer control to your application + located at the 4 MiB offset of the flash image. +* If you prefer, you can use ``-serial stdio`` instead of ``-nographic``. + +Machine-specific options +------------------------ + +Unless otherwise noted by the patch series, there are no special board +options beyond the standard QEMU options shown above. Commonly useful +generic options include: + +* ``-s -S`` to open a GDB stub on TCP port 1234 and start paused, so you can + debug both QEMU and the guest. +* ``-d guest_errors,unimp`` (or other trace flags) for additional logging. + +Example: debugging with GDB:: + + $ /path/to/qemu-system-riscv32 -nographic -machine neorv32 \ + -bios /path/to/neorv32/bootloader/neorv32_raw_exe.bin \ + -drive file=$HOME/flash_contents.bin,if=mtd,format=raw \ + -s -S + + # In another shell: + $ riscv32-unknown-elf-gdb /path/to/neorv32/bootloader/main.elf + (gdb) target remote :1234 + + +Known limitations +----------------- + +This is a functional model intended for software bring-up and testing of +example programs. It may not model all timing details or every optional +peripheral available in a specific NEORV32 SoC configuration. + diff --git a/docs/system/target-riscv.rst b/docs/system/target-riscv.rst index 89b2cb732c..fbd8270022 100644 --- a/docs/system/target-riscv.rst +++ b/docs/system/target-riscv.rst @@ -68,6 +68,7 @@ undocumented; you can get a complete list by running riscv/microblaze-v-generic riscv/microchip-icicle-kit + riscv/neorv32 riscv/shakti-c riscv/sifive_u riscv/virt diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig index fc9c35bd98..976acd2a1b 100644 --- a/hw/riscv/Kconfig +++ b/hw/riscv/Kconfig @@ -128,3 +128,11 @@ config XIANGSHAN_KUNMINGHU select RISCV_APLIC select RISCV_IMSIC select SERIAL_MM + +config NEORV32 + bool + default y + depends on RISCV32 + select NEORV32_UART + select NEORV32_SPI + select NEORV32_SYSINFO_QEMU diff --git a/hw/riscv/meson.build b/hw/riscv/meson.build index 2a8d5b136c..b8788e2035 100644 --- a/hw/riscv/meson.build +++ b/hw/riscv/meson.build @@ -14,5 +14,6 @@ riscv_ss.add(when: 'CONFIG_RISCV_IOMMU', if_true: files( 'riscv-iommu.c', 'riscv-iommu-pci.c', 'riscv-iommu-sys.c', 'riscv-iommu-hpm.c')) riscv_ss.add(when: 'CONFIG_MICROBLAZE_V', if_true: files('microblaze-v-generic.c')) riscv_ss.add(when: 'CONFIG_XIANGSHAN_KUNMINGHU', if_true: files('xiangshan_kmh.c')) +riscv_ss.add(when: 'CONFIG_NEORV32', if_true: files('neorv32.c')) hw_arch += {'riscv': riscv_ss} diff --git a/hw/riscv/neorv32.c b/hw/riscv/neorv32.c new file mode 100644 index 0000000000..41494d2893 --- /dev/null +++ b/hw/riscv/neorv32.c @@ -0,0 +1,215 @@ +/* + * QEMU RISC-V Board Compatible with Neorv32 IP + * + * Provides a board compatible with the Neorv32 IP: + * + * 0) SYSINFO + * 1) IMEM + * 2) DMEM + * 3) UART + * 4) SPI + * + * Copyright (c) 2025 Michael Levit + * SPDX-License-Identifier: GPL-2.0-or-later + */ + + +#include "qemu/osdep.h" +#include "qemu/cutils.h" +#include "qemu/error-report.h" +#include "qapi/error.h" +#include "hw/boards.h" +#include "hw/loader.h" +#include "hw/sysbus.h" +#include "hw/char/serial.h" +#include "hw/misc/unimp.h" +#include "target/riscv/cpu.h" +#include "hw/riscv/riscv_hart.h" +#include "hw/riscv/boot.h" +#include "hw/intc/riscv_aclint.h" +#include "chardev/char.h" +#include "system/system.h" +#include "hw/ssi/ssi.h" /* For ssi_realize_and_unref() */ + +#include "hw/riscv/neorv32.h" +#include "hw/misc/neorv32_sysinfo.h" +#include "hw/char/neorv32_uart.h" +#include "hw/ssi/neorv32_spi.h" + +/* TODO: get BOOTLOADER_ROM, IMEM, DMEM sizes from rtl auto-generated header */ +static const MemMapEntry neorv32_memmap[] = { + + [NEORV32_IMEM] = { NEORV32_IMEM_BASE, SYSINFO_IMEM_SIZE}, + [NEORV32_BOOTLOADER_ROM] = { NEORV32_BOOTLOADER_BASE_ADDRESS, 0x2000}, + [NEORV32_DMEM] = { NEORV32_DMEM_BASE, SYSINFO_DMEM_SIZE}, + [NEORV32_SYSINFO] = { NEORV32_SYSINFO_BASE, 0x100}, + [NEORV32_UART0] = { NEORV32_UART0_BASE, 0x100}, + [NEORV32_SPI0] = { NEORV32_SPI_BASE, 0x100}, +}; + +static void neorv32_machine_init(MachineState *machine) +{ + MachineClass *mc = MACHINE_GET_CLASS(machine); + const MemMapEntry *memmap = neorv32_memmap; + + Neorv32State *s = NEORV32_MACHINE(machine); + MemoryRegion *sys_mem = get_system_memory(); + int i; + RISCVBootInfo boot_info; + hwaddr start_addr = memmap[NEORV32_BOOTLOADER_ROM].base; + + if (machine->ram_size != mc->default_ram_size) { + char *sz = size_to_str(mc->default_ram_size); + error_report("Invalid RAM size, should be %s", sz); + g_free(sz); + exit(EXIT_FAILURE); + } + + /* Initialize SoC */ + object_initialize_child(OBJECT(machine), "soc", &s->soc, + TYPE_RISCV_NEORV32_SOC); + qdev_realize(DEVICE(&s->soc), NULL, &error_fatal); + + /* Data Tightly Integrated Memory */ + memory_region_add_subregion(sys_mem, + memmap[NEORV32_DMEM].base, machine->ram); + + /* Instruction Memory (IMEM) */ + memory_region_init_ram(&s->soc.imem_region, OBJECT(&s->soc), + "riscv.neorv32.imem", + memmap[NEORV32_IMEM].size, &error_fatal); + memory_region_add_subregion(sys_mem, memmap[NEORV32_IMEM].base, + &s->soc.imem_region); + + /* Mask ROM reset vector */ + uint32_t reset_vec[4]; + + reset_vec[1] = 0x204002b7; /* 0x1004: lui t0,0x20400 */ + reset_vec[2] = 0x00028067; /* 0x1008: jr t0 */ + reset_vec[0] = reset_vec[3] = 0; + + /* copy in the reset vector in little_endian byte order */ + for (i = 0; i < sizeof(reset_vec) >> 2; i++) { + reset_vec[i] = cpu_to_le32(reset_vec[i]); + } + + /* Neorv32 bootloader */ + if (machine->firmware) { + riscv_find_and_load_firmware(machine, machine->firmware, + &start_addr, NULL); + } + + /* Neorv32 example applications */ + riscv_boot_info_init(&boot_info, &s->soc.cpus); + if (machine->kernel_filename) { + riscv_load_kernel(machine, &boot_info, + memmap[NEORV32_IMEM].base, + false, NULL); + } +} + +static void neorv32_machine_instance_init(Object *obj) +{ + + /* Placeholder for now */ + /* Neorv32State *s = NEORV32_MACHINE(obj); */ +} + +static void neorv32_machine_class_init(ObjectClass *oc, const void *data) +{ + MachineClass *mc = MACHINE_CLASS(oc); + + mc->desc = "RISC-V SOC compatible with Neorv32 SDK"; + mc->init = neorv32_machine_init; + mc->max_cpus = 1; + mc->default_cpu_type = NEORV32_CPU; + mc->default_ram_id = "riscv.neorv32.dmem"; + mc->default_ram_size = neorv32_memmap[NEORV32_DMEM].size; + +} + +static const TypeInfo neorv32_machine_typeinfo = { + .name = MACHINE_TYPE_NAME("neorv32"), + .parent = TYPE_MACHINE, + .class_init = neorv32_machine_class_init, + .instance_init = neorv32_machine_instance_init, + .instance_size = sizeof(Neorv32State), +}; + +static void neorv32_machine_init_register_types(void) +{ + type_register_static(&neorv32_machine_typeinfo); +} + +type_init(neorv32_machine_init_register_types) + +static void neorv32_soc_init(Object *obj) +{ + MachineState *ms = MACHINE(qdev_get_machine()); + Neorv32SoCState *s = RISCV_NEORV32_SOC(obj); + + object_initialize_child(obj, "cpus", &s->cpus, TYPE_RISCV_HART_ARRAY); + object_property_set_int(OBJECT(&s->cpus), "num-harts", ms->smp.cpus, + &error_abort); + + object_property_set_int(OBJECT(&s->cpus), "resetvec", + NEORV32_BOOTLOADER_BASE_ADDRESS, &error_abort); + +} + +static void neorv32_soc_realize(DeviceState *dev, Error **errp) +{ + MachineState *ms = MACHINE(qdev_get_machine()); + const MemMapEntry *memmap = neorv32_memmap; + Neorv32SoCState *s = RISCV_NEORV32_SOC(dev); + MemoryRegion *sys_mem = get_system_memory(); + + object_property_set_str(OBJECT(&s->cpus), "cpu-type", ms->cpu_type, + &error_abort); + sysbus_realize(SYS_BUS_DEVICE(&s->cpus), &error_fatal); + + /* Bootloader ROM */ + memory_region_init_rom(&s->bootloader_rom, OBJECT(dev), + "riscv.bootloader.rom", + memmap[NEORV32_BOOTLOADER_ROM].size, &error_fatal); + memory_region_add_subregion(sys_mem, + memmap[NEORV32_BOOTLOADER_ROM].base, &s->bootloader_rom); + + + /* Sysinfo ROM */ + neorv32_sysinfo_create(sys_mem, memmap[NEORV32_SYSINFO].base); + + /* Uart0 */ + neorv32_uart_create(sys_mem, memmap[NEORV32_UART0].base, serial_hd(0)); + + /* SPI controller */ + NEORV32SPIState *spi = neorv32_spi_create(sys_mem, + memmap[NEORV32_SPI0].base); + + if (!spi) { + error_setg(errp, "SPI is not created"); + return; + } +} + +static void neorv32_soc_class_init(ObjectClass *oc, const void *data) +{ + DeviceClass *dc = DEVICE_CLASS(oc); + dc->realize = neorv32_soc_realize; + dc->user_creatable = false; +} + +static const TypeInfo neorv32_soc_type_info = { + .name = TYPE_RISCV_NEORV32_SOC, + .parent = TYPE_DEVICE, + .instance_size = sizeof(Neorv32SoCState), + .instance_init = neorv32_soc_init, + .class_init = neorv32_soc_class_init, +}; + +static void neorv32_soc_register_types(void) +{ + type_register_static(&neorv32_soc_type_info); +} + +type_init(neorv32_soc_register_types) diff --git a/include/hw/riscv/neorv32.h b/include/hw/riscv/neorv32.h new file mode 100644 index 0000000000..bc90c2bc04 --- /dev/null +++ b/include/hw/riscv/neorv32.h @@ -0,0 +1,54 @@ +/* + * NEORV32 SOC presentation in QEMU + * + * Copyright (c) 2025 Michael Levit + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#ifndef HW_NEORV32_H +#define HW_NEORV32_H + +#include "hw/riscv/riscv_hart.h" +#include "hw/boards.h" + +#if defined(TARGET_RISCV32) +#define NEORV32_CPU TYPE_RISCV_CPU_NEORV32 +#endif + +#define TYPE_RISCV_NEORV32_SOC "riscv.neorv32.soc" +#define RISCV_NEORV32_SOC(obj) \ + OBJECT_CHECK(Neorv32SoCState, (obj), TYPE_RISCV_NEORV32_SOC) + +typedef struct Neorv32SoCState { + /*< private >*/ + DeviceState parent_obj; + + /*< public >*/ + RISCVHartArrayState cpus; + DeviceState *plic; + MemoryRegion imem_region; + MemoryRegion bootloader_rom; +} Neorv32SoCState; + +typedef struct Neorv32State { + /*< private >*/ + MachineState parent_obj; + + /*< public >*/ + Neorv32SoCState soc; +} Neorv32State; + +#define TYPE_NEORV32_MACHINE MACHINE_TYPE_NAME("neorv32") +#define NEORV32_MACHINE(obj) \ + OBJECT_CHECK(Neorv32State, (obj), TYPE_NEORV32_MACHINE) + +enum { + NEORV32_IMEM, + NEORV32_BOOTLOADER_ROM, + NEORV32_DMEM, + NEORV32_SYSINFO, + NEORV32_UART0, + NEORV32_SPI0, +}; + +#endif /* HW_NEORV32_H */ -- 2.51.1
