Re: [PATCH 1/5] arm: apple: Add initial support for Apple's M1 SoC

[Bin Meng <bmeng.cn@gmail.com>]

Hi Mark,

On Sat, Sep 18, 2021 at 9:55 PM Mark Kettenis <kettenis@openbsd.org> wrote:
>
> Add support for Apple's M1 SoC that is used in "Apple Silicon"
> Macs.  This builds a basic U-Boot that can be used as a payload
> for the m1n1 boot loader being developed by the Asahi Linux
> project.
>
> Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
> ---
>  arch/arm/Kconfig                    |  22 ++++
>  arch/arm/Makefile                   |   1 +
>  arch/arm/mach-apple/Kconfig         |  18 ++++
>  arch/arm/mach-apple/Makefile        |   4 +
>  arch/arm/mach-apple/board.c         | 158 ++++++++++++++++++++++++++++
>  arch/arm/mach-apple/lowlevel_init.S |  16 +++
>  configs/apple_m1_defconfig          |  14 +++
>  include/configs/apple.h             |  38 +++++++
>  8 files changed, 271 insertions(+)
>  create mode 100644 arch/arm/mach-apple/Kconfig
>  create mode 100644 arch/arm/mach-apple/Makefile
>  create mode 100644 arch/arm/mach-apple/board.c
>  create mode 100644 arch/arm/mach-apple/lowlevel_init.S
>  create mode 100644 configs/apple_m1_defconfig
>  create mode 100644 include/configs/apple.h
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index b5bd3284cd..7cdea1f615 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -895,6 +895,26 @@ config ARCH_NEXELL
>         select DM
>         select GPIO_EXTRA_HEADER
>
> +config ARCH_APPLE
> +       bool "Apple SoCs"
> +       select ARM64
> +       select LINUX_KERNEL_IMAGE_HEADER
> +       select POSITION_INDEPENDENT
> +       select BLK
> +       select DM
> +       select DM_KEYBOARD
> +       select DM_SERIAL
> +       select DM_USB
> +       select DM_VIDEO
> +       select CMD_USB
> +       select MISC
> +       select OF_CONTROL
> +       select OF_BOARD
> +       select USB
> +       imply CMD_DM
> +       imply CMD_GPT
> +       imply DISTRO_DEFAULTS
> +
>  config ARCH_OWL
>         bool "Actions Semi OWL SoCs"
>         select DM
> @@ -1932,6 +1952,8 @@ config ISW_ENTRY_ADDR
>           image headers.
>  endif
>
> +source "arch/arm/mach-apple/Kconfig"
> +
>  source "arch/arm/mach-aspeed/Kconfig"
>
>  source "arch/arm/mach-at91/Kconfig"
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index c68e598a67..44178c204b 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -51,6 +51,7 @@ PLATFORM_CPPFLAGS += $(arch-y) $(tune-y)
>
>  # Machine directory name.  This list is sorted alphanumerically
>  # by CONFIG_* macro name.
> +machine-$(CONFIG_ARCH_APPLE)           += apple
>  machine-$(CONFIG_ARCH_ASPEED)          += aspeed
>  machine-$(CONFIG_ARCH_AT91)            += at91
>  machine-$(CONFIG_ARCH_BCM283X)         += bcm283x
> diff --git a/arch/arm/mach-apple/Kconfig b/arch/arm/mach-apple/Kconfig
> new file mode 100644
> index 0000000000..66cab91b2a
> --- /dev/null
> +++ b/arch/arm/mach-apple/Kconfig
> @@ -0,0 +1,18 @@
> +if ARCH_APPLE
> +
> +config SYS_TEXT_BASE
> +       default 0x00000000
> +
> +config SYS_CONFIG_NAME
> +       default "apple"
> +
> +config SYS_SOC
> +       default "m1"
> +
> +config SYS_MALLOC_LEN
> +       default 0x4000000
> +
> +config SYS_MALLOC_F_LEN
> +       default 0x4000
> +
> +endif
> diff --git a/arch/arm/mach-apple/Makefile b/arch/arm/mach-apple/Makefile
> new file mode 100644
> index 0000000000..e74a8c9df1
> --- /dev/null
> +++ b/arch/arm/mach-apple/Makefile
> @@ -0,0 +1,4 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +
> +obj-y += board.o
> +obj-y += lowlevel_init.o
> diff --git a/arch/arm/mach-apple/board.c b/arch/arm/mach-apple/board.c
> new file mode 100644
> index 0000000000..0c8b35292e
> --- /dev/null
> +++ b/arch/arm/mach-apple/board.c
> @@ -0,0 +1,158 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * (C) Copyright 2021 Mark Kettenis <kettenis@openbsd.org>
> + */
> +
> +#include <common.h>
> +#include <efi_loader.h>
> +
> +#include <asm/armv8/mmu.h>
> +#include <asm/global_data.h>
> +#include <asm/io.h>
> +#include <asm/system.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +static struct mm_region apple_mem_map[] = {
> +       {
> +               /* I/O */
> +               .virt = 0x200000000,
> +               .phys = 0x200000000,
> +               .size = 8UL * SZ_1G,
> +               .attrs = PTE_BLOCK_MEMTYPE(MT_DEVICE_NGNRNE) |
> +                        PTE_BLOCK_NON_SHARE |
> +                        PTE_BLOCK_PXN | PTE_BLOCK_UXN
> +       }, {
> +               /* I/O */
> +               .virt = 0x500000000,
> +               .phys = 0x500000000,
> +               .size = 2UL * SZ_1G,
> +               .attrs = PTE_BLOCK_MEMTYPE(MT_DEVICE_NGNRNE) |
> +                        PTE_BLOCK_NON_SHARE |
> +                        PTE_BLOCK_PXN | PTE_BLOCK_UXN
> +       }, {
> +               /* I/O */
> +               .virt = 0x680000000,
> +               .phys = 0x680000000,
> +               .size = SZ_512M,
> +               .attrs = PTE_BLOCK_MEMTYPE(MT_DEVICE_NGNRNE) |
> +                        PTE_BLOCK_NON_SHARE |
> +                        PTE_BLOCK_PXN | PTE_BLOCK_UXN
> +       }, {
> +               /* PCIE */
> +               .virt = 0x6a0000000,
> +               .phys = 0x6a0000000,
> +               .size = SZ_512M,
> +               .attrs = PTE_BLOCK_MEMTYPE(MT_DEVICE_NGNRE) |
> +                        PTE_BLOCK_INNER_SHARE |
> +                        PTE_BLOCK_PXN | PTE_BLOCK_UXN
> +       }, {
> +               /* PCIE */
> +               .virt = 0x6c0000000,
> +               .phys = 0x6c0000000,
> +               .size = SZ_1G,
> +               .attrs = PTE_BLOCK_MEMTYPE(MT_DEVICE_NGNRE) |
> +                        PTE_BLOCK_INNER_SHARE |
> +                        PTE_BLOCK_PXN | PTE_BLOCK_UXN
> +       }, {
> +               /* RAM */
> +               .virt = 0x800000000,
> +               .phys = 0x800000000,
> +               .size = 8UL * SZ_1G,
> +               .attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL) |
> +                        PTE_BLOCK_INNER_SHARE
> +       }, {
> +               /* Empty entry for framebuffer */
> +               0,
> +       }, {
> +               /* List terminator */
> +               0,
> +       }
> +};
> +
> +struct mm_region *mem_map = apple_mem_map;
> +
> +int board_init(void)
> +{
> +       return 0;
> +}
> +
> +int dram_init(void)
> +{
> +       int index, node, ret;
> +       fdt_addr_t base;
> +       fdt_size_t size;
> +
> +       ret = fdtdec_setup_mem_size_base();
> +       if (ret)
> +               return ret;
> +
> +       /* Update RAM mapping. */

nits: please remove the ending .

> +       index = ARRAY_SIZE(apple_mem_map) - 3;
> +       apple_mem_map[index].virt = gd->ram_base;
> +       apple_mem_map[index].phys = gd->ram_base;
> +       apple_mem_map[index].size = gd->ram_size;
> +
> +       node = fdt_path_offset(gd->fdt_blob, "/chosen/framebuffer");
> +       if (node < 0)
> +               return 0;
> +
> +       base = fdtdec_get_addr_size(gd->fdt_blob, node, "reg", &size);
> +       if (base == FDT_ADDR_T_NONE)
> +               return 0;
> +
> +       /* Add framebuffer mapping. */

ditto

> +       index = ARRAY_SIZE(apple_mem_map) - 2;
> +       apple_mem_map[index].virt = base;
> +       apple_mem_map[index].phys = base;
> +       apple_mem_map[index].size = size;
> +       apple_mem_map[index].attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL_NC) |
> +               PTE_BLOCK_INNER_SHARE | PTE_BLOCK_PXN | PTE_BLOCK_UXN;
> +
> +       return 0;
> +}
> +
> +int dram_init_banksize(void)
> +{
> +       return fdtdec_setup_memory_banksize();
> +}
> +
> +#define APPLE_WDT_BASE         0x23d2b0000ULL
> +
> +#define APPLE_WDT_SYS_CTL_ENABLE       BIT(2)
> +
> +typedef struct apple_wdt {
> +       u32     reserved0[3];
> +       u32     chip_ctl;
> +       u32     sys_tmr;
> +       u32     sys_cmp;
> +       u32     reserved1;
> +       u32     sys_ctl;
> +} apple_wdt_t;
> +
> +void reset_cpu(void)

This looks like we should add a new sysreset driver for Apple Arm SoC.

> +{
> +       apple_wdt_t *wdt = (apple_wdt_t *)APPLE_WDT_BASE;
> +
> +       writel(0, &wdt->sys_cmp);
> +       writel(APPLE_WDT_SYS_CTL_ENABLE, &wdt->sys_ctl);
> +
> +       while(1)
> +               wfi();
> +}
> +
> +extern long fw_dtb_pointer;
> +
> +void *board_fdt_blob_setup(void)
> +{
> +       return (void *)fw_dtb_pointer;
> +}
> +
> +ulong board_get_usable_ram_top(ulong total_size)
> +{
> +       /*
> +        * Top part of RAM is used by firmware for things like the
> +        * framebuffer.  This gives us plenty of room to play with.
> +        */
> +       return 0x980000000;
> +}
> diff --git a/arch/arm/mach-apple/lowlevel_init.S b/arch/arm/mach-apple/lowlevel_init.S
> new file mode 100644
> index 0000000000..0f5313163e
> --- /dev/null
> +++ b/arch/arm/mach-apple/lowlevel_init.S
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * (C) Copyright 2021 Mark Kettenis <kettenis@openbsd.org>
> + */
> +
> +.align 8
> +.global fw_dtb_pointer
> +fw_dtb_pointer:
> +       .quad   0

Is this filled in by m1n1?

> +
> +.global save_boot_params
> +save_boot_params:
> +       adr     x1, fw_dtb_pointer
> +       str     x0, [x1]
> +
> +       b       save_boot_params_ret
> diff --git a/configs/apple_m1_defconfig b/configs/apple_m1_defconfig
> new file mode 100644
> index 0000000000..a7ae15576b
> --- /dev/null
> +++ b/configs/apple_m1_defconfig
> @@ -0,0 +1,14 @@
> +CONFIG_ARM=y
> +CONFIG_ARCH_APPLE=y
> +# CONFIG_DISPLAY_CPUINFO is not set
> +# CONFIG_MMC is not set
> +# CONFIG_NET is not set
> +CONFIG_VIDEO_SIMPLE=y
> +CONFIG_DISPLAY_BOARDINFO_LATE=y
> +CONFIG_USB_XHCI_HCD=y
> +CONFIG_USB_XHCI_DWC3=y
> +CONFIG_USB_KEYBOARD=y
> +CONFIG_USB_STORAGE=y
> +CONFIG_USE_PREBOOT=y
> +CONFIG_PREBOOT="usb start"
> +# CONFIG_GENERATE_SMBIOS_TABLE is not set
> diff --git a/include/configs/apple.h b/include/configs/apple.h
> new file mode 100644
> index 0000000000..1c246af002
> --- /dev/null
> +++ b/include/configs/apple.h
> @@ -0,0 +1,38 @@
> +#ifndef __CONFIG_H
> +#define __CONFIG_H
> +
> +#include <linux/sizes.h>
> +
> +#define CONFIG_SYS_LOAD_ADDR   0x880000000
> +
> +#define CONFIG_SYS_SDRAM_BASE  0x880000000
> +
> +#define CONFIG_LNX_KRNL_IMG_TEXT_OFFSET_BASE   CONFIG_SYS_TEXT_BASE
> +
> +/* Environment */
> +#define ENV_DEVICE_SETTINGS \
> +       "stdin=serial,usbkbd\0" \
> +       "stdout=serial,vidconsole\0" \
> +       "stderr=serial,vidconsole\0"
> +
> +#define ENV_MEM_LAYOUT_SETTINGS \
> +       "fdt_addr_r=0x960100000\0" \
> +       "kernel_addr_r=0x960200000\0"
> +
> +#if CONFIG_IS_ENABLED(CMD_USB)
> +       #define BOOT_TARGET_USB(func) func(USB, usb, 0)
> +#else
> +       #define BOOT_TARGET_USB(func)
> +#endif
> +
> +#define BOOT_TARGET_DEVICES(func) \
> +       BOOT_TARGET_USB(func)
> +
> +#include <config_distro_bootcmd.h>
> +
> +#define CONFIG_EXTRA_ENV_SETTINGS \
> +       ENV_DEVICE_SETTINGS \
> +       ENV_MEM_LAYOUT_SETTINGS \
> +       BOOTENV
> +
> +#endif

Regards,
Bin