target/linux/generic/pending-4.4/092-MIPS-ZBOOT-copy-appended-dtb-to-the-end-of-the-kerne.patch

   1 From b8f54f2cde788623f41d11327688c75aed34092f Mon Sep 17 00:00:00 2001
   2 From: Jonas Gorski <jogo@openwrt.org>
   3 Date: Mon, 20 Jun 2016 11:27:36 +0200
   4 Subject: [PATCH 1/2] MIPS: ZBOOT: copy appended dtb to the end of the kernel
   5
   6 Instead of rewriting the arguments, just move the appended dtb to where
   7 the decompressed kernel expects it. This eliminates the need for special
   8 casing vmlinuz.bin appended dtb files.
   9
  10 Signed-off-by: Jonas Gorski <jogo@openwrt.org>
  11 Cc: Kevin Cernekee <cernekee@gmail.com>
  12 Cc: Florian Fainelli <f.fainelli@gmail.com>
  13 Cc: John Crispin <john@phrozen.org>
  14 Cc: Paul Burton <paul.burton@imgtec.com>
  15 Cc: James Hogan <james.hogan@imgtec.com>
  16 Cc: Alban Bedel <albeu@free.fr>
  17 Cc: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
  18 Cc: Antony Pavlov <antonynpavlov@gmail.com>
  19 Cc: linux-mips@linux-mips.org
  20 Patchwork: https://patchwork.linux-mips.org/patch/13698/
  21 Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
  22 ---
  23  arch/mips/Kconfig                      | 22 ++--------------------
  24  arch/mips/boot/compressed/decompress.c | 17 +++++++++++++++++
  25  arch/mips/boot/compressed/head.S       | 16 ----------------
  26  3 files changed, 19 insertions(+), 36 deletions(-)
  27
  28 --- a/arch/mips/Kconfig
  29 +++ b/arch/mips/Kconfig
  30 @@ -2753,10 +2753,10 @@ choice
  31                   the documented boot protocol using a device tree.
  32
  33         config MIPS_RAW_APPENDED_DTB
  34 -               bool "vmlinux.bin"
  35 +               bool "vmlinux.bin or vmlinuz.bin"
  36                 help
  37                   With this option, the boot code will look for a device tree binary
  38 -                 DTB) appended to raw vmlinux.bin (without decompressor).
  39 +                 DTB) appended to raw vmlinux.bin or vmlinuz.bin.
  40                   (e.g. cat vmlinux.bin <filename>.dtb > vmlinux_w_dtb).
  41
  42                   This is meant as a backward compatibility convenience for those
  43 @@ -2768,24 +2768,6 @@ choice
  44                   look like a DTB header after a reboot if no actual DTB is appended
  45                   to vmlinux.bin.  Do not leave this option active in a production kernel
  46                   if you don't intend to always append a DTB.
  47 -
  48 -       config MIPS_ZBOOT_APPENDED_DTB
  49 -               bool "vmlinuz.bin"
  50 -               depends on SYS_SUPPORTS_ZBOOT
  51 -               help
  52 -                 With this option, the boot code will look for a device tree binary
  53 -                 DTB) appended to raw vmlinuz.bin (with decompressor).
  54 -                 (e.g. cat vmlinuz.bin <filename>.dtb > vmlinuz_w_dtb).
  55 -
  56 -                 This is meant as a backward compatibility convenience for those
  57 -                 systems with a bootloader that can't be upgraded to accommodate
  58 -                 the documented boot protocol using a device tree.
  59 -
  60 -                 Beware that there is very little in terms of protection against
  61 -                 this option being confused by leftover garbage in memory that might
  62 -                 look like a DTB header after a reboot if no actual DTB is appended
  63 -                 to vmlinuz.bin.  Do not leave this option active in a production kernel
  64 -                 if you don't intend to always append a DTB.
  65  endchoice
  66
  67  choice
  68 --- a/arch/mips/boot/compressed/decompress.c
  69 +++ b/arch/mips/boot/compressed/decompress.c
  70 @@ -14,6 +14,7 @@
  71  #include <linux/types.h>
  72  #include <linux/kernel.h>
  73  #include <linux/string.h>
  74 +#include <linux/libfdt.h>
  75
  76  #include <asm/addrspace.h>
  77
  78 @@ -36,6 +37,8 @@ extern void puthex(unsigned long long va
  79  #define puthex(val) do {} while (0)
  80  #endif
  81
  82 +extern char __appended_dtb[];
  83 +
  84  void error(char *x)
  85  {
  86         puts("\n\n");
  87 @@ -114,6 +117,20 @@ void decompress_kernel(unsigned long boo
  88         __decompress((char *)zimage_start, zimage_size, 0, 0,
  89                    (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, 0, error);
  90
  91 +       if (IS_ENABLED(CONFIG_MIPS_RAW_APPENDED_DTB) &&
  92 +           fdt_magic((void *)&__appended_dtb) == FDT_MAGIC) {
  93 +               unsigned int image_size, dtb_size;
  94 +
  95 +               dtb_size = fdt_totalsize((void *)&__appended_dtb);
  96 +
  97 +               /* last four bytes is always image size in little endian */
  98 +               image_size = le32_to_cpup((void *)&__image_end - 4);
  99 +
 100 +               /* copy dtb to where the booted kernel will expect it */
 101 +               memcpy((void *)VMLINUX_LOAD_ADDRESS_ULL + image_size,
 102 +                      __appended_dtb, dtb_size);
 103 +       }
 104 +
 105         /* FIXME: should we flush cache here? */
 106         puts("Now, booting the kernel...\n");
 107  }
 108 --- a/arch/mips/boot/compressed/head.S
 109 +++ b/arch/mips/boot/compressed/head.S
 110 @@ -25,22 +25,6 @@ start:
 111         move    s2, a2
 112         move    s3, a3
 113
 114 -#ifdef CONFIG_MIPS_ZBOOT_APPENDED_DTB
 115 -       PTR_LA  t0, __appended_dtb
 116 -#ifdef CONFIG_CPU_BIG_ENDIAN
 117 -       li      t1, 0xd00dfeed
 118 -#else
 119 -       li      t1, 0xedfe0dd0
 120 -#endif
 121 -       lw      t2, (t0)
 122 -       bne     t1, t2, not_found
 123 -        nop
 124 -
 125 -       move    s1, t0
 126 -       PTR_LI  s0, -2
 127 -not_found:
 128 -#endif
 129 -
 130         /* Clear BSS */
 131         PTR_LA  a0, _edata
 132         PTR_LA  a2, _end