openwrtv4/target/linux/generic/patches-4.4/092-MIPS-ZBOOT-copy-appended-dtb-to-the-end-of-the-kerne.patch
Felix Fietkau 1708644f19 kernel: backport MIPS changes introducing a separate IRQ stack
Prevents crashes when IRQs arrive when the current kernel stack context
already contains deeply nested function calls, e.g. when stacking lots
of network devices on top of each other

Signed-off-by: Felix Fietkau <nbd@nbd.name>
2017-01-15 18:25:54 +01:00

132 lines
4.3 KiB
Diff

From b8f54f2cde788623f41d11327688c75aed34092f Mon Sep 17 00:00:00 2001
From: Jonas Gorski <jogo@openwrt.org>
Date: Mon, 20 Jun 2016 11:27:36 +0200
Subject: [PATCH 1/2] MIPS: ZBOOT: copy appended dtb to the end of the kernel
Instead of rewriting the arguments, just move the appended dtb to where
the decompressed kernel expects it. This eliminates the need for special
casing vmlinuz.bin appended dtb files.
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: John Crispin <john@phrozen.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Alban Bedel <albeu@free.fr>
Cc: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13698/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/Kconfig | 22 ++--------------------
arch/mips/boot/compressed/decompress.c | 17 +++++++++++++++++
arch/mips/boot/compressed/head.S | 16 ----------------
3 files changed, 19 insertions(+), 36 deletions(-)
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2753,10 +2753,10 @@ choice
the documented boot protocol using a device tree.
config MIPS_RAW_APPENDED_DTB
- bool "vmlinux.bin"
+ bool "vmlinux.bin or vmlinuz.bin"
help
With this option, the boot code will look for a device tree binary
- DTB) appended to raw vmlinux.bin (without decompressor).
+ DTB) appended to raw vmlinux.bin or vmlinuz.bin.
(e.g. cat vmlinux.bin <filename>.dtb > vmlinux_w_dtb).
This is meant as a backward compatibility convenience for those
@@ -2768,24 +2768,6 @@ choice
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.
-
- config MIPS_ZBOOT_APPENDED_DTB
- bool "vmlinuz.bin"
- depends on SYS_SUPPORTS_ZBOOT
- help
- With this option, the boot code will look for a device tree binary
- DTB) appended to raw vmlinuz.bin (with decompressor).
- (e.g. cat vmlinuz.bin <filename>.dtb > vmlinuz_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 vmlinuz.bin. Do not leave this option active in a production kernel
- if you don't intend to always append a DTB.
endchoice
choice
--- a/arch/mips/boot/compressed/decompress.c
+++ b/arch/mips/boot/compressed/decompress.c
@@ -14,6 +14,7 @@
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
+#include <linux/libfdt.h>
#include <asm/addrspace.h>
@@ -36,6 +37,8 @@ extern void puthex(unsigned long long va
#define puthex(val) do {} while (0)
#endif
+extern char __appended_dtb[];
+
void error(char *x)
{
puts("\n\n");
@@ -114,6 +117,20 @@ void decompress_kernel(unsigned long boo
__decompress((char *)zimage_start, zimage_size, 0, 0,
(void *)VMLINUX_LOAD_ADDRESS_ULL, 0, 0, error);
+ if (IS_ENABLED(CONFIG_MIPS_RAW_APPENDED_DTB) &&
+ fdt_magic((void *)&__appended_dtb) == FDT_MAGIC) {
+ unsigned int image_size, dtb_size;
+
+ dtb_size = fdt_totalsize((void *)&__appended_dtb);
+
+ /* last four bytes is always image size in little endian */
+ image_size = le32_to_cpup((void *)&__image_end - 4);
+
+ /* copy dtb to where the booted kernel will expect it */
+ memcpy((void *)VMLINUX_LOAD_ADDRESS_ULL + image_size,
+ __appended_dtb, dtb_size);
+ }
+
/* FIXME: should we flush cache here? */
puts("Now, booting the kernel...\n");
}
--- a/arch/mips/boot/compressed/head.S
+++ b/arch/mips/boot/compressed/head.S
@@ -25,22 +25,6 @@ start:
move s2, a2
move s3, a3
-#ifdef CONFIG_MIPS_ZBOOT_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 s1, t0
- PTR_LI s0, -2
-not_found:
-#endif
-
/* Clear BSS */
PTR_LA a0, _edata
PTR_LA a2, _end