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- From 1da8f1798e307fb8422753984339beb00025f97d Mon Sep 17 00:00:00 2001
- From: Jonas Gorski <jogo@openwrt.org>
- Date: Sun, 12 Apr 2015 12:24:58 +0200
- Subject: [PATCH] MIPS: Add support for vmlinux.bin appended dtb
- Add support for detecting a vmlinux.bin appended dtb and overriding
- the boot arguments to match the UHI interface.
- Due to the PERCPU section being empty for !SMP, but still modifying
- the current address by aligning it to the page size, do not define
- it for !SMP builds to allow __appended_dtb to still point to
- the actual end of the data.
- Signed-off-by: Jonas Gorski <jogo@openwrt.org>
- Cc: linux-mips@linux-mips.org
- Cc: devicetree@vger.kernel.org
- Cc: John Crispin <blogic@openwrt.org>
- Cc: Kevin Cernekee <cernekee@gmail.com>
- Cc: Florian Fainelli <f.fainelli@gmail.com>
- Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
- Cc: Markos Chandras <markos.chandras@imgtec.com>
- Cc: Andrew Bresticker <abrestic@chromium.org>
- Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
- Cc: Paul Burton <paul.burton@imgtec.com>
- Cc: James Hartley <James.Hartley@imgtec.com>
- Patchwork: https://patchwork.linux-mips.org/patch/9739/
- Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
- ---
- arch/mips/Kconfig | 27 +++++++++++++++++++++++++++
- arch/mips/kernel/head.S | 16 ++++++++++++++++
- arch/mips/kernel/vmlinux.lds.S | 8 +++++++-
- 3 files changed, 50 insertions(+), 1 deletion(-)
- --- a/arch/mips/Kconfig
- +++ b/arch/mips/Kconfig
- @@ -2703,6 +2703,33 @@ config BOOT_RAW
-
-
-
- +choice
- + prompt "Kernel appended dtb support" if OF
- + default MIPS_NO_APPENDED_DTB
- +
- + config MIPS_NO_APPENDED_DTB
- + bool "None"
- + help
- + Do not enable appended dtb support.
- +
- + config MIPS_RAW_APPENDED_DTB
- + bool "vmlinux.bin"
- + help
- + With this option, the boot code will look for a device tree binary
- + DTB) appended to raw vmlinux.bin (without decompressor).
- + (e.g. cat vmlinux.bin <filename>.dtb > vmlinux_w_dtb).
- +
- + This is meant as a backward compatibility convenience for those
- + systems with a bootloader that can't be upgraded to accommodate
- + the documented boot protocol using a device tree.
- +
- + Beware that there is very little in terms of protection against
- + this option being confused by leftover garbage in memory that might
- + look like a DTB header after a reboot if no actual DTB is appended
- + to vmlinux.bin. Do not leave this option active in a production kernel
- + if you don't intend to always append a DTB.
- +endchoice
- +
- endmenu
-
- config LOCKDEP_SUPPORT
- --- a/arch/mips/kernel/head.S
- +++ b/arch/mips/kernel/head.S
- @@ -100,6 +100,22 @@ NESTED(kernel_entry, 16, sp) # kernel
- jr t0
- 0:
-
- +#ifdef CONFIG_MIPS_RAW_APPENDED_DTB
- + PTR_LA t0, __appended_dtb
- +
- +#ifdef CONFIG_CPU_BIG_ENDIAN
- + li t1, 0xd00dfeed
- +#else
- + li t1, 0xedfe0dd0
- +#endif
- + lw t2, (t0)
- + bne t1, t2, not_found
- + nop
- +
- + move a1, t0
- + PTR_LI a0, -2
- +not_found:
- +#endif
- PTR_LA t0, __bss_start # clear .bss
- LONG_S zero, (t0)
- PTR_LA t1, __bss_stop - LONGSIZE
- --- a/arch/mips/kernel/vmlinux.lds.S
- +++ b/arch/mips/kernel/vmlinux.lds.S
- @@ -125,8 +125,14 @@ SECTIONS
- .exit.data : {
- EXIT_DATA
- }
- -
- +#ifdef CONFIG_SMP
- PERCPU_SECTION(1 << CONFIG_MIPS_L1_CACHE_SHIFT)
- +#endif
- +#ifdef CONFIG_MIPS_RAW_APPENDED_DTB
- + __appended_dtb = .;
- + /* leave space for appended DTB */
- + . += 0x100000;
- +#endif
- /*
- * Align to 64K in attempt to eliminate holes before the
- * .bss..swapper_pg_dir section at the start of .bss. This
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