The bootloader used on the Realtek RTL9302C boards is an ancient vendor fork of U-Boot that doesn't understand device trees. So to run a modern kernel it is necessary use one of the APPENDED_DTB options. When appending the DTB the inintrd information, if present, needs to be inserted into the /chosen device tree node. The bootloader provides the initrd start/size via the firmware environment. Add a fdt fixup that will update the device tree with the initrd information. Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx> --- arch/mips/generic/Makefile | 1 + arch/mips/generic/board-realtek.c | 81 +++++++++++++++++++++++++++++++ 2 files changed, 82 insertions(+) create mode 100644 arch/mips/generic/board-realtek.c diff --git a/arch/mips/generic/Makefile b/arch/mips/generic/Makefile index 56011d738441..ea0e4ad5e600 100644 --- a/arch/mips/generic/Makefile +++ b/arch/mips/generic/Makefile @@ -13,3 +13,4 @@ obj-$(CONFIG_LEGACY_BOARD_SEAD3) += board-sead3.o obj-$(CONFIG_LEGACY_BOARD_OCELOT) += board-ocelot.o obj-$(CONFIG_MACH_INGENIC) += board-ingenic.o obj-$(CONFIG_VIRT_BOARD_RANCHU) += board-ranchu.o +obj-$(CONFIG_MACH_REALTEK_RTL) += board-realtek.o diff --git a/arch/mips/generic/board-realtek.c b/arch/mips/generic/board-realtek.c new file mode 100644 index 000000000000..91563efbc61f --- /dev/null +++ b/arch/mips/generic/board-realtek.c @@ -0,0 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2024 Allied Telesis + */ + +#include <linux/errno.h> +#include <linux/libfdt.h> +#include <linux/of_address.h> +#include <linux/types.h> + +#include <asm/fw/fw.h> +#include <asm/machine.h> + +static __init int realtek_add_initrd(void *fdt) +{ + int node, err; + u32 start, size; + + node = fdt_path_offset(fdt, "/chosen"); + if (node < 0) { + pr_err("/chosen node not found\n"); + return -ENOENT; + } + + start = fw_getenvl("initrd_start"); + size = fw_getenvl("initrd_size"); + + if (start == 0 && size == 0) + return 0; + + pr_info("Adding initrd info from environment\n"); + + err = fdt_setprop_u32(fdt, node, "linux,initrd-start", start); + if (err) { + pr_err("unable to set initrd-start: %d\n", err); + return err; + } + + err = fdt_setprop_u32(fdt, node, "linux,initrd-end", start + size); + if (err) { + pr_err("unable to set initrd-end: %d\n", err); + return err; + } + + return 0; +} + +static const struct mips_fdt_fixup realtek_fdt_fixups[] __initconst = { + { realtek_add_initrd, "add initrd" }, + {}, +}; + +static __init const void *realtek_fixup_fdt(const void *fdt, const void *match_data) +{ + static unsigned char fdt_buf[16 << 10] __initdata; + int err; + + if (fdt_check_header(fdt)) + panic("Corrupt DT"); + + fw_init_cmdline(); + + err = apply_mips_fdt_fixups(fdt_buf, sizeof(fdt_buf), fdt, realtek_fdt_fixups); + if (err) + panic("Unable to fixup FDT: %d", err); + + return fdt_buf; + +} + +static const struct of_device_id realtek_of_match[] __initconst = { + { + .compatible = "realtek,rtl930x-soc", + }, + {} +}; + +MIPS_MACHINE(realtek) = { + .matches = realtek_of_match, + .fixup_fdt = realtek_fixup_fdt, +}; -- 2.45.2