467ffbf2208ab6bda6f39909c62c2db189ffa47a
[openwrt/openwrt.git] / target / linux / ipq806x / patches-4.9 / 0067-generic-Mangle-bootloader-s-kernel-arguments.patch
1 From 71270226b14733a4b1f2cde58ea9265caa50b38d Mon Sep 17 00:00:00 2001
2 From: Adrian Panella <ianchi74@outlook.com>
3 Date: Thu, 9 Mar 2017 09:37:17 +0100
4 Subject: [PATCH 67/69] generic: Mangle bootloader's kernel arguments
5
6 The command-line arguments provided by the boot loader will be
7 appended to a new device tree property: bootloader-args.
8 If there is a property "append-rootblock" in DT under /chosen
9 and a root= option in bootloaders command line it will be parsed
10 and added to DT bootargs with the form: <append-rootblock>XX.
11 Only command line ATAG will be processed, the rest of the ATAGs
12 sent by bootloader will be ignored.
13 This is usefull in dual boot systems, to get the current root partition
14 without afecting the rest of the system.
15
16 Signed-off-by: Adrian Panella <ianchi74@outlook.com>
17 ---
18 arch/arm/Kconfig | 11 +++++
19 arch/arm/boot/compressed/atags_to_fdt.c | 72 ++++++++++++++++++++++++++++++++-
20 init/main.c | 16 ++++++++
21 3 files changed, 98 insertions(+), 1 deletion(-)
22
23 --- a/arch/arm/Kconfig
24 +++ b/arch/arm/Kconfig
25 @@ -1948,6 +1948,17 @@ config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEN
26 The command-line arguments provided by the boot loader will be
27 appended to the the device tree bootargs property.
28
29 +config ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
30 + bool "Append rootblock parsing bootloader's kernel arguments"
31 + help
32 + The command-line arguments provided by the boot loader will be
33 + appended to a new device tree property: bootloader-args.
34 + If there is a property "append-rootblock" in DT under /chosen
35 + and a root= option in bootloaders command line it will be parsed
36 + and added to DT bootargs with the form: <append-rootblock>XX.
37 + Only command line ATAG will be processed, the rest of the ATAGs
38 + sent by bootloader will be ignored.
39 +
40 endchoice
41
42 config CMDLINE
43 --- a/arch/arm/boot/compressed/atags_to_fdt.c
44 +++ b/arch/arm/boot/compressed/atags_to_fdt.c
45 @@ -3,6 +3,8 @@
46
47 #if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND)
48 #define do_extend_cmdline 1
49 +#elif defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
50 +#define do_extend_cmdline 1
51 #else
52 #define do_extend_cmdline 0
53 #endif
54 @@ -66,6 +68,59 @@ static uint32_t get_cell_size(const void
55 return cell_size;
56 }
57
58 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
59 +
60 +static char *append_rootblock(char *dest, const char *str, int len, void *fdt)
61 +{
62 + char *ptr, *end;
63 + char *root="root=";
64 + int i, l;
65 + const char *rootblock;
66 +
67 + //ARM doesn't have __HAVE_ARCH_STRSTR, so search manually
68 + ptr = str - 1;
69 +
70 + do {
71 + //first find an 'r' at the begining or after a space
72 + do {
73 + ptr++;
74 + ptr = strchr(ptr, 'r');
75 + if(!ptr) return dest;
76 +
77 + } while (ptr != str && *(ptr-1) != ' ');
78 +
79 + //then check for the rest
80 + for(i = 1; i <= 4; i++)
81 + if(*(ptr+i) != *(root+i)) break;
82 +
83 + } while (i != 5);
84 +
85 + end = strchr(ptr, ' ');
86 + end = end ? (end - 1) : (strchr(ptr, 0) - 1);
87 +
88 + //find partition number (assumes format root=/dev/mtdXX | /dev/mtdblockXX | yy:XX )
89 + for( i = 0; end >= ptr && *end >= '0' && *end <= '9'; end--, i++);
90 + ptr = end + 1;
91 +
92 + /* if append-rootblock property is set use it to append to command line */
93 + rootblock = getprop(fdt, "/chosen", "append-rootblock", &l);
94 + if(rootblock != NULL) {
95 + if(*dest != ' ') {
96 + *dest = ' ';
97 + dest++;
98 + len++;
99 + }
100 + if (len + l + i <= COMMAND_LINE_SIZE) {
101 + memcpy(dest, rootblock, l);
102 + dest += l - 1;
103 + memcpy(dest, ptr, i);
104 + dest += i;
105 + }
106 + }
107 + return dest;
108 +}
109 +#endif
110 +
111 static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline)
112 {
113 char cmdline[COMMAND_LINE_SIZE];
114 @@ -85,12 +140,21 @@ static void merge_fdt_bootargs(void *fdt
115
116 /* and append the ATAG_CMDLINE */
117 if (fdt_cmdline) {
118 +
119 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
120 + //save original bootloader args
121 + //and append ubi.mtd with root partition number to current cmdline
122 + setprop_string(fdt, "/chosen", "bootloader-args", fdt_cmdline);
123 + ptr = append_rootblock(ptr, fdt_cmdline, len, fdt);
124 +
125 +#else
126 len = strlen(fdt_cmdline);
127 if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) {
128 *ptr++ = ' ';
129 memcpy(ptr, fdt_cmdline, len);
130 ptr += len;
131 }
132 +#endif
133 }
134 *ptr = '\0';
135
136 @@ -147,7 +211,9 @@ int atags_to_fdt(void *atag_list, void *
137 else
138 setprop_string(fdt, "/chosen", "bootargs",
139 atag->u.cmdline.cmdline);
140 - } else if (atag->hdr.tag == ATAG_MEM) {
141 + }
142 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
143 + else if (atag->hdr.tag == ATAG_MEM) {
144 if (memcount >= sizeof(mem_reg_property)/4)
145 continue;
146 if (!atag->u.mem.size)
147 @@ -186,6 +252,10 @@ int atags_to_fdt(void *atag_list, void *
148 setprop(fdt, "/memory", "reg", mem_reg_property,
149 4 * memcount * memsize);
150 }
151 +#else
152 +
153 + }
154 +#endif
155
156 return fdt_pack(fdt);
157 }
158 --- a/init/main.c
159 +++ b/init/main.c
160 @@ -87,6 +87,10 @@
161 #include <asm/sections.h>
162 #include <asm/cacheflush.h>
163
164 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
165 +#include <linux/of.h>
166 +#endif
167 +
168 static int kernel_init(void *);
169
170 extern void init_IRQ(void);
171 @@ -537,6 +541,18 @@ asmlinkage __visible void __init start_k
172 page_alloc_init();
173
174 pr_notice("Kernel command line: %s\n", boot_command_line);
175 +
176 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
177 + //Show bootloader's original command line for reference
178 + if(of_chosen) {
179 + const char *prop = of_get_property(of_chosen, "bootloader-args", NULL);
180 + if(prop)
181 + pr_notice("Bootloader command line (ignored): %s\n", prop);
182 + else
183 + pr_notice("Bootloader command line not present\n");
184 + }
185 +#endif
186 +
187 parse_early_param();
188 after_dashes = parse_args("Booting kernel",
189 static_command_line, __start___param,