mirror of https://github.com/hak5/openwrt-owl.git
125 lines
3.7 KiB
Diff
125 lines
3.7 KiB
Diff
From 318c1fce4aeef298cbb6153416c499c94ad7cda0 Mon Sep 17 00:00:00 2001
|
|
From: Jonas Gorski <jogo@openwrt.org>
|
|
Date: Tue, 24 Jun 2014 10:53:15 +0200
|
|
Subject: [PATCH RFC v3] MIPS: add support for vmlinux.bin appended DTB
|
|
|
|
Add support for populating initial_boot_params through a dtb
|
|
blob appended to raw vmlinux.bin.
|
|
|
|
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
|
|
---
|
|
Changes RFC v2 -> v3
|
|
|
|
* fixed !smp kernels (TODO: move it to its own patch
|
|
|
|
Changes RFC v1 -> v2
|
|
|
|
* changed all occurences of vmlinux to vmlinux.bin
|
|
* clarified this applies to the raw vmlinux.bin without decompressor
|
|
* s/initial_device_params/initial_boot_params/
|
|
|
|
Initial comments by me still valid:
|
|
|
|
Mostly adapted from how ARM is doing it.
|
|
|
|
Sent as an RFC PATCH because I am not sure if this is the right way to
|
|
it, and whether storing the pointer in initial_boot_params is a good
|
|
idea, or a new variable should be introduced.
|
|
|
|
The reasoning for initial_boot_params is that there is no common
|
|
MIPS interface yet, so the next best thing was using that. This also
|
|
has the advantage of keeping the original fw_args intact.
|
|
|
|
This patch works for me on bcm63xx, where the bootloader expects
|
|
an lzma compressed kernel, so I didn't want to double compress using
|
|
the in-kernel compressed kernel support.
|
|
|
|
Completely untested on anything except MIPS32 / big endian.
|
|
|
|
arch/mips/Kconfig | 18 ++++++++++++++++++
|
|
arch/mips/kernel/head.S | 19 +++++++++++++++++++
|
|
arch/mips/kernel/vmlinux.lds.S | 7 +++++++
|
|
3 files changed, 43 insertions(+)
|
|
|
|
--- a/arch/mips/Kconfig
|
|
+++ b/arch/mips/Kconfig
|
|
@@ -2655,6 +2655,24 @@ config RAPIDIO
|
|
|
|
source "drivers/rapidio/Kconfig"
|
|
|
|
+config MIPS_APPENDED_DTB
|
|
+ bool "Use appended device tree blob to vmlinux.bin (EXPERIMENTAL)"
|
|
+ depends on OF
|
|
+ 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.
|
|
+
|
|
endmenu
|
|
|
|
menu "Executable file formats"
|
|
--- 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_APPENDED_DTB
|
|
+ PTR_LA t0, __appended_dtb
|
|
+ PTR_LI t3, 0
|
|
+
|
|
+#ifdef CONFIG_CPU_BIG_ENDIAN
|
|
+ PTR_LI t1, 0xd00dfeed
|
|
+#else
|
|
+ PTR_LI t1, 0xedfe0dd0
|
|
+#endif
|
|
+ LONG_L t2, (t0)
|
|
+ bne t1, t2, not_found
|
|
+
|
|
+ PTR_LA t3, __appended_dtb
|
|
+
|
|
+not_found:
|
|
+#endif
|
|
PTR_LA t0, __bss_start # clear .bss
|
|
LONG_S zero, (t0)
|
|
PTR_LA t1, __bss_stop - LONGSIZE
|
|
@@ -113,6 +129,10 @@ NESTED(kernel_entry, 16, sp) # kernel
|
|
LONG_S a2, fw_arg2
|
|
LONG_S a3, fw_arg3
|
|
|
|
+#ifdef CONFIG_MIPS_APPENDED_DTB
|
|
+ LONG_S t3, initial_boot_params
|
|
+#endif
|
|
+
|
|
MTC0 zero, CP0_CONTEXT # clear context register
|
|
PTR_LA $28, init_thread_union
|
|
/* Set the SP after an empty pt_regs. */
|
|
--- 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_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
|