Add support for the QEMU 'virt' machine on the m68k architecture. This board emulates a generic machine based on the Motorola 68040 CPU equipped with Goldfish virtual peripherals.
Introduce the necessary board configuration and initialization infrastructure. The implementation includes logic to parse the QEMU bootinfo interface, enabling dynamic detection of system RAM size to adapt to the virtual machine's configuration. Enable the Goldfish TTY driver for serial console output. Additionally, enable Goldfish RTC and timer drivers to support real-time clock functionality and nanosecond-resolution delays. Include comprehensive documentation covering build instructions and usage examples. Signed-off-by: Kuan-Wei Chiu <[email protected]> Tested-by: Daniel Palmer <[email protected]> --- No changes in v4. arch/m68k/Kconfig | 8 ++ board/emulation/qemu-m68k/Kconfig | 12 +++ board/emulation/qemu-m68k/MAINTAINERS | 8 ++ board/emulation/qemu-m68k/Makefile | 5 ++ board/emulation/qemu-m68k/qemu-m68k.c | 115 ++++++++++++++++++++++++++ configs/qemu-m68k_defconfig | 16 ++++ doc/board/emulation/index.rst | 1 + doc/board/emulation/qemu-m68k.rst | 39 +++++++++ include/configs/qemu-m68k.h | 18 ++++ 9 files changed, 222 insertions(+) create mode 100644 board/emulation/qemu-m68k/Kconfig create mode 100644 board/emulation/qemu-m68k/MAINTAINERS create mode 100644 board/emulation/qemu-m68k/Makefile create mode 100644 board/emulation/qemu-m68k/qemu-m68k.c create mode 100644 configs/qemu-m68k_defconfig create mode 100644 doc/board/emulation/qemu-m68k.rst create mode 100644 include/configs/qemu-m68k.h diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index de7c673c376..605ae5ec20c 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -183,6 +183,13 @@ config TARGET_STMARK2 select CF_DSPI select M54418 +config TARGET_QEMU_M68K + bool "Support QEMU m68k virt" + select M68040 + help + This target supports the QEMU m68k virtual machine (-M virt). + It simulates a Motorola 68040 CPU with Goldfish peripherals. + endchoice config SYS_CPU @@ -208,6 +215,7 @@ source "board/freescale/m5329evb/Kconfig" source "board/freescale/m5373evb/Kconfig" source "board/sysam/amcore/Kconfig" source "board/sysam/stmark2/Kconfig" +source "board/emulation/qemu-m68k/Kconfig" config M68K_QEMU bool "Build with workarounds for incomplete QEMU emulation" diff --git a/board/emulation/qemu-m68k/Kconfig b/board/emulation/qemu-m68k/Kconfig new file mode 100644 index 00000000000..aae6dfe400f --- /dev/null +++ b/board/emulation/qemu-m68k/Kconfig @@ -0,0 +1,12 @@ +if TARGET_QEMU_M68K + +config SYS_BOARD + default "qemu-m68k" + +config SYS_VENDOR + default "emulation" + +config SYS_CONFIG_NAME + default "qemu-m68k" + +endif diff --git a/board/emulation/qemu-m68k/MAINTAINERS b/board/emulation/qemu-m68k/MAINTAINERS new file mode 100644 index 00000000000..90414c58465 --- /dev/null +++ b/board/emulation/qemu-m68k/MAINTAINERS @@ -0,0 +1,8 @@ +QEMU M68K VIRT BOARD +M: Kuan-Wei Chiu <[email protected]> +S: Maintained +F: board/emulation/qemu-m68k/ +F: board/emulation/common/ +F: include/configs/qemu-m68k.h +F: configs/qemu-m68k_defconfig +F: doc/board/emulation/qemu-m68k.rst diff --git a/board/emulation/qemu-m68k/Makefile b/board/emulation/qemu-m68k/Makefile new file mode 100644 index 00000000000..5cb2886ff5a --- /dev/null +++ b/board/emulation/qemu-m68k/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0-or-later +# +# Copyright (C) 2025, Kuan-Wei Chiu <[email protected]> + +obj-y += qemu-m68k.o diff --git a/board/emulation/qemu-m68k/qemu-m68k.c b/board/emulation/qemu-m68k/qemu-m68k.c new file mode 100644 index 00000000000..3b911b95343 --- /dev/null +++ b/board/emulation/qemu-m68k/qemu-m68k.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2025, Kuan-Wei Chiu <[email protected]> + */ + +#include <asm-generic/sections.h> +#include <asm/bootinfo.h> +#include <asm/global_data.h> +#include <asm/io.h> +#include <config.h> +#include <dm/platdata.h> +#include <goldfish_rtc.h> +#include <goldfish_timer.h> +#include <goldfish_tty.h> +#include <init.h> +#include <linux/errno.h> +#include <serial.h> + +DECLARE_GLOBAL_DATA_PTR; + +/* QEMU Virt Machine Hardware Map */ +#define VIRT_GF_RTC_MMIO_BASE 0xff007000 +#define VIRT_GF_TTY_MMIO_BASE 0xff008000 +#define VIRT_CTRL_MMIO_BASE 0xff009000 +#define VIRT_CTRL_RESET 0x01 + +/* + * Theoretical limit derivation: + * Max Bootinfo Size (Standard Page) = 4096 bytes + * Min Record Size (Tag + Size) = 4 bytes + * Max Records = 4096 / 4 = 1024 + */ +#define MAX_BOOTINFO_RECORDS 1024 + +int board_early_init_f(void) +{ + return 0; +} + +int checkboard(void) +{ + puts("Board: QEMU m68k virt\n"); + return 0; +} + +int dram_init(void) +{ + struct bi_record *record; + ulong addr; + int loops = 0; + + /* Default: 16MB */ + gd->ram_size = 0x01000000; + + /* QEMU places bootinfo after _end, aligned to 2 bytes */ + addr = (ulong)&_end; + addr = ALIGN(addr, 2); + + record = (struct bi_record *)addr; + + if (record->tag != BI_MACHTYPE) + return 0; + + while (record->tag != BI_LAST) { + if (++loops > MAX_BOOTINFO_RECORDS) + panic("Bootinfo loop exceeded"); + if (record->tag == BI_MEMCHUNK) { + gd->ram_size = record->data[1]; + break; + } + record = (struct bi_record *)((ulong)record + record->size); + } + + return 0; +} + +void reset_cpu(unsigned long addr) +{ + writel(VIRT_CTRL_RESET, VIRT_CTRL_MMIO_BASE); + while (1) + ; +} + +int do_reset(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) +{ + reset_cpu(0); + return 0; +} + +static const struct goldfish_rtc_plat rtc_plat = { + .base = (void __iomem *)VIRT_GF_RTC_MMIO_BASE, +}; + +U_BOOT_DRVINFO(goldfish_rtc) = { + .name = "rtc_goldfish", + .plat = &rtc_plat, +}; + +static const struct goldfish_timer_plat timer_plat = { + .base = (void __iomem *)VIRT_GF_RTC_MMIO_BASE, +}; + +U_BOOT_DRVINFO(goldfish_timer) = { + .name = "goldfish_timer", + .plat = &timer_plat, +}; + +static const struct goldfish_tty_plat serial_plat = { + .base = (void __iomem *)VIRT_GF_TTY_MMIO_BASE, +}; + +U_BOOT_DRVINFO(goldfish_serial) = { + .name = "serial_goldfish", + .plat = &serial_plat, +}; diff --git a/configs/qemu-m68k_defconfig b/configs/qemu-m68k_defconfig new file mode 100644 index 00000000000..f9294218429 --- /dev/null +++ b/configs/qemu-m68k_defconfig @@ -0,0 +1,16 @@ +CONFIG_M68K=y +CONFIG_TEXT_BASE=0x00000000 +CONFIG_SYS_MALLOC_LEN=0x20000 +CONFIG_SYS_MALLOC_F_LEN=0x2000 +CONFIG_SYS_MONITOR_LEN=262144 +CONFIG_SYS_BOOTM_LEN=0x1000000 +CONFIG_SYS_LOAD_ADDR=0x00000000 +CONFIG_TARGET_QEMU_M68K=y +# CONFIG_DISPLAY_BOARDINFO is not set +CONFIG_BOARD_EARLY_INIT_F=y +CONFIG_DM_RTC=y +CONFIG_RTC_GOLDFISH=y +CONFIG_DM_SERIAL=y +CONFIG_SERIAL_GOLDFISH=y +CONFIG_TIMER=y +CONFIG_GOLDFISH_TIMER=y diff --git a/doc/board/emulation/index.rst b/doc/board/emulation/index.rst index f8908166276..4f7c812d493 100644 --- a/doc/board/emulation/index.rst +++ b/doc/board/emulation/index.rst @@ -15,6 +15,7 @@ Emulation qemu-sbsa qemu-x86 qemu-xtensa + qemu-m68k Also see diff --git a/doc/board/emulation/qemu-m68k.rst b/doc/board/emulation/qemu-m68k.rst new file mode 100644 index 00000000000..6c4de54cf6a --- /dev/null +++ b/doc/board/emulation/qemu-m68k.rst @@ -0,0 +1,39 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later +.. Copyright (C) 2025, Kuan-Wei Chiu <[email protected]> + +QEMU m68k +========= + +QEMU for m68k supports a special 'virt' machine designed for emulation and +virtualization purposes. This document describes how to run U-Boot under it. + +The QEMU virt machine models a generic m68k virtual machine with Goldfish +interfaces. It supports the Motorola 68040 CPU architecture. + +Building U-Boot +--------------- +Set the CROSS_COMPILE environment variable to your m68k toolchain, and run: + +.. code-block:: bash + + export CROSS_COMPILE=m68k-linux-gnu- + make qemu-m68k_defconfig + make + +Running U-Boot +-------------- +The minimal QEMU command line to get U-Boot up and running is: + +.. code-block:: bash + + qemu-system-m68k -M virt -cpu m68040 -nographic -kernel u-boot + +Note that the `-nographic` option is used to redirect the console to stdio, +which connects to the emulated Goldfish TTY device. + +Hardware Support +---------------- +The following QEMU virt peripherals are supported in U-Boot: + +* Goldfish TTY (Serial Console) +* Goldfish RTC (Real Time Clock) diff --git a/include/configs/qemu-m68k.h b/include/configs/qemu-m68k.h new file mode 100644 index 00000000000..1d8aa92fe80 --- /dev/null +++ b/include/configs/qemu-m68k.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2025, Kuan-Wei Chiu <[email protected]> + */ + +#ifndef __QEMU_M68K_H +#define __QEMU_M68K_H + +/* Memory Configuration */ +#define CFG_SYS_SDRAM_BASE 0x00000000 + +/* + * Initial Stack Pointer: + * Place the stack at 4MB offset to avoid overwriting U-Boot code/data. + */ +#define CFG_SYS_INIT_SP_ADDR (CFG_SYS_SDRAM_BASE + 0x400000) + +#endif /* __QEMU_M68K_H */ -- 2.52.0.358.g0dd7633a29-goog
