[LEDE-DEV] [PATCH] kernel: preserve bootargs when using appended dtb
Hauke Mehrtens
hauke at hauke-m.de
Thu Aug 25 14:20:16 PDT 2016
backport a patch from upstream Linux kernel which stores the appended
dtb not in the same resisters as defined in the UHI specification, use
a separate variable on MIPS.
Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
...copy-appended-dtb-to-the-end-of-the-kerne.patch | 132 +++++++++++++++++++++
...re-the-appended-dtb-address-in-a-variable.patch | 121 +++++++++++++++++++
.../patches-4.4/300-mips_expose_boot_raw.patch | 2 +-
...re-the-appended-dtb-address-in-a-variable.patch | 49 ++++++++
4 files changed, 303 insertions(+), 1 deletion(-)
create mode 100644 target/linux/generic/patches-4.4/092-MIPS-ZBOOT-copy-appended-dtb-to-the-end-of-the-kerne.patch
create mode 100644 target/linux/generic/patches-4.4/093-MIPS-store-the-appended-dtb-address-in-a-variable.patch
create mode 100644 target/linux/lantiq/patches-4.4/122-MIPS-store-the-appended-dtb-address-in-a-variable.patch
diff --git a/target/linux/generic/patches-4.4/092-MIPS-ZBOOT-copy-appended-dtb-to-the-end-of-the-kerne.patch b/target/linux/generic/patches-4.4/092-MIPS-ZBOOT-copy-appended-dtb-to-the-end-of-the-kerne.patch
new file mode 100644
index 0000000..71df429
--- /dev/null
+++ b/target/linux/generic/patches-4.4/092-MIPS-ZBOOT-copy-appended-dtb-to-the-end-of-the-kerne.patch
@@ -0,0 +1,132 @@
+From b8f54f2cde788623f41d11327688c75aed34092f Mon Sep 17 00:00:00 2001
+From: Jonas Gorski <jogo at 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 at openwrt.org>
+Cc: Kevin Cernekee <cernekee at gmail.com>
+Cc: Florian Fainelli <f.fainelli at gmail.com>
+Cc: John Crispin <john at phrozen.org>
+Cc: Paul Burton <paul.burton at imgtec.com>
+Cc: James Hogan <james.hogan at imgtec.com>
+Cc: Alban Bedel <albeu at free.fr>
+Cc: Daniel Gimpelevich <daniel at gimpelevich.san-francisco.ca.us>
+Cc: Antony Pavlov <antonynpavlov at gmail.com>
+Cc: linux-mips at linux-mips.org
+Patchwork: https://patchwork.linux-mips.org/patch/13698/
+Signed-off-by: Ralf Baechle <ralf at 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
+@@ -2752,10 +2752,10 @@ 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
+@@ -2767,24 +2767,6 @@ 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
diff --git a/target/linux/generic/patches-4.4/093-MIPS-store-the-appended-dtb-address-in-a-variable.patch b/target/linux/generic/patches-4.4/093-MIPS-store-the-appended-dtb-address-in-a-variable.patch
new file mode 100644
index 0000000..643e473
--- /dev/null
+++ b/target/linux/generic/patches-4.4/093-MIPS-store-the-appended-dtb-address-in-a-variable.patch
@@ -0,0 +1,121 @@
+From 15f37e1588920e010f20b53f04af94e91b8ee714 Mon Sep 17 00:00:00 2001
+From: Jonas Gorski <jogo at openwrt.org>
+Date: Mon, 20 Jun 2016 11:27:37 +0200
+Subject: [PATCH] MIPS: store the appended dtb address in a variable
+
+Instead of rewriting the arguments to match the UHI spec, store the
+address of a appended or UHI supplied dtb in fw_supplied_dtb.
+
+That way the original bootloader arugments are kept intact while still
+making the use of an appended dtb invisible for mach code.
+
+Mach code can still find out if it is an appended dtb by comparing
+fw_arg1 with fw_supplied_dtb.
+
+Signed-off-by: Jonas Gorski <jogo at openwrt.org>
+Cc: Kevin Cernekee <cernekee at gmail.com>
+Cc: Florian Fainelli <f.fainelli at gmail.com>
+Cc: John Crispin <john at phrozen.org>
+Cc: Paul Burton <paul.burton at imgtec.com>
+Cc: James Hogan <james.hogan at imgtec.com>
+Cc: Alban Bedel <albeu at free.fr>
+Cc: Daniel Gimpelevich <daniel at gimpelevich.san-francisco.ca.us>
+Cc: Antony Pavlov <antonynpavlov at gmail.com>
+Cc: linux-mips at linux-mips.org
+Patchwork: https://patchwork.linux-mips.org/patch/13699/
+Signed-off-by: Ralf Baechle <ralf at linux-mips.org>
+---
+ arch/mips/ath79/setup.c | 4 ++--
+ arch/mips/bmips/setup.c | 4 ++--
+ arch/mips/include/asm/bootinfo.h | 4 ++++
+ arch/mips/kernel/head.S | 21 ++++++++++++++-------
+ arch/mips/kernel/setup.c | 4 ++++
+ arch/mips/lantiq/prom.c | 4 ++--
+ arch/mips/pic32/pic32mzda/init.c | 4 ++--
+ 7 files changed, 30 insertions(+), 15 deletions(-)
+
+--- a/arch/mips/bmips/setup.c
++++ b/arch/mips/bmips/setup.c
+@@ -149,8 +149,8 @@ void __init plat_mem_setup(void)
+ /* intended to somewhat resemble ARM; see Documentation/arm/Booting */
+ if (fw_arg0 == 0 && fw_arg1 == 0xffffffff)
+ dtb = phys_to_virt(fw_arg2);
+- else if (fw_arg0 == -2) /* UHI interface */
+- dtb = (void *)fw_arg1;
++ else if (fw_passed_dtb) /* UHI interface */
++ dtb = (void *)fw_passed_dtb;
+ else if (__dtb_start != __dtb_end)
+ dtb = (void *)__dtb_start;
+ else
+--- a/arch/mips/include/asm/bootinfo.h
++++ b/arch/mips/include/asm/bootinfo.h
+@@ -127,6 +127,10 @@ extern char arcs_cmdline[COMMAND_LINE_SI
+ */
+ extern unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
+
++#ifdef CONFIG_USE_OF
++extern unsigned long fw_passed_dtb;
++#endif
++
+ /*
+ * Platform memory detection hook called by setup_arch
+ */
+--- a/arch/mips/kernel/head.S
++++ b/arch/mips/kernel/head.S
+@@ -94,21 +94,24 @@ NESTED(kernel_entry, 16, sp) # kernel
+ jr t0
+ 0:
+
++#ifdef CONFIG_USE_OF
+ #ifdef CONFIG_MIPS_RAW_APPENDED_DTB
+- PTR_LA t0, __appended_dtb
++ PTR_LA t2, __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:
++ lw t0, (t2)
++ beq t0, t1, dtb_found
++#endif
++ li t1, -2
++ beq a0, t1, dtb_found
++ move t2, a1
++
++ li t2, 0
++dtb_found:
+ #endif
+ PTR_LA t0, __bss_start # clear .bss
+ LONG_S zero, (t0)
+@@ -123,6 +126,10 @@ not_found:
+ LONG_S a2, fw_arg2
+ LONG_S a3, fw_arg3
+
++#ifdef CONFIG_USE_OF
++ LONG_S t2, fw_passed_dtb
++#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/setup.c
++++ b/arch/mips/kernel/setup.c
+@@ -814,6 +814,10 @@ void __init setup_arch(char **cmdline_p)
+ unsigned long kernelsp[NR_CPUS];
+ unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
+
++#ifdef CONFIG_USE_OF
++unsigned long fw_passed_dtb;
++#endif
++
+ #ifdef CONFIG_DEBUG_FS
+ struct dentry *mips_debugfs_dir;
+ static int __init debugfs_mips(void)
diff --git a/target/linux/generic/patches-4.4/300-mips_expose_boot_raw.patch b/target/linux/generic/patches-4.4/300-mips_expose_boot_raw.patch
index cd7d28a..76c7078 100644
--- a/target/linux/generic/patches-4.4/300-mips_expose_boot_raw.patch
+++ b/target/linux/generic/patches-4.4/300-mips_expose_boot_raw.patch
@@ -18,7 +18,7 @@ Acked-by: Rob Landley <rob at landley.net>
config CEVT_BCM1480
bool
-@@ -2810,6 +2807,18 @@ choice
+@@ -2792,6 +2789,18 @@ choice
bool "Bootloader kernel arguments if available"
endchoice
diff --git a/target/linux/lantiq/patches-4.4/122-MIPS-store-the-appended-dtb-address-in-a-variable.patch b/target/linux/lantiq/patches-4.4/122-MIPS-store-the-appended-dtb-address-in-a-variable.patch
new file mode 100644
index 0000000..a6641bf
--- /dev/null
+++ b/target/linux/lantiq/patches-4.4/122-MIPS-store-the-appended-dtb-address-in-a-variable.patch
@@ -0,0 +1,49 @@
+From 15f37e1588920e010f20b53f04af94e91b8ee714 Mon Sep 17 00:00:00 2001
+From: Jonas Gorski <jogo at openwrt.org>
+Date: Mon, 20 Jun 2016 11:27:37 +0200
+Subject: [PATCH] MIPS: store the appended dtb address in a variable
+
+Instead of rewriting the arguments to match the UHI spec, store the
+address of a appended or UHI supplied dtb in fw_supplied_dtb.
+
+That way the original bootloader arugments are kept intact while still
+making the use of an appended dtb invisible for mach code.
+
+Mach code can still find out if it is an appended dtb by comparing
+fw_arg1 with fw_supplied_dtb.
+
+Signed-off-by: Jonas Gorski <jogo at openwrt.org>
+Cc: Kevin Cernekee <cernekee at gmail.com>
+Cc: Florian Fainelli <f.fainelli at gmail.com>
+Cc: John Crispin <john at phrozen.org>
+Cc: Paul Burton <paul.burton at imgtec.com>
+Cc: James Hogan <james.hogan at imgtec.com>
+Cc: Alban Bedel <albeu at free.fr>
+Cc: Daniel Gimpelevich <daniel at gimpelevich.san-francisco.ca.us>
+Cc: Antony Pavlov <antonynpavlov at gmail.com>
+Cc: linux-mips at linux-mips.org
+Patchwork: https://patchwork.linux-mips.org/patch/13699/
+Signed-off-by: Ralf Baechle <ralf at linux-mips.org>
+---
+ arch/mips/ath79/setup.c | 4 ++--
+ arch/mips/bmips/setup.c | 4 ++--
+ arch/mips/include/asm/bootinfo.h | 4 ++++
+ arch/mips/kernel/head.S | 21 ++++++++++++++-------
+ arch/mips/kernel/setup.c | 4 ++++
+ arch/mips/lantiq/prom.c | 4 ++--
+ arch/mips/pic32/pic32mzda/init.c | 4 ++--
+ 7 files changed, 30 insertions(+), 15 deletions(-)
+
+--- a/arch/mips/lantiq/prom.c
++++ b/arch/mips/lantiq/prom.c
+@@ -74,8 +74,8 @@ void __init plat_mem_setup(void)
+
+ set_io_port_base((unsigned long) KSEG1);
+
+- if (fw_arg0 == -2) /* UHI interface */
+- dtb = (void *)fw_arg1;
++ if (fw_passed_dtb) /* UHI interface */
++ dtb = (void *)fw_passed_dtb;
+ else if (__dtb_start != __dtb_end)
+ dtb = (void *)__dtb_start;
+ else
--
2.9.3
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