53275607e028b73b5145ffa7f4ba024261364ab1
[openwrt/openwrt.git] / target / linux / mvebu / patches-4.14 / 006-mvebu-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 This patch has been modified to be mvebu specific. The original patch
19 did not pass the bootloader cmdline on if no append-rootblock stanza
20 was found, resulting in blank cmdline and failure to boot.
21
22 Signed-off-by: Michael Gray <michael.gray@lantisproject.com>
23 ---
24 arch/arm/Kconfig | 11 +++++
25 arch/arm/boot/compressed/atags_to_fdt.c | 72 ++++++++++++++++++++++++++++++++-
26 init/main.c | 16 ++++++++
27 3 files changed, 98 insertions(+), 1 deletion(-)
28
29 --- a/arch/arm/Kconfig
30 +++ b/arch/arm/Kconfig
31 @@ -1948,6 +1948,17 @@ config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEN
32 The command-line arguments provided by the boot loader will be
33 appended to the the device tree bootargs property.
34
35 +config ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
36 + bool "Append rootblock parsing bootloader's kernel arguments"
37 + help
38 + The command-line arguments provided by the boot loader will be
39 + appended to a new device tree property: bootloader-args.
40 + If there is a property "append-rootblock" in DT under /chosen
41 + and a root= option in bootloaders command line it will be parsed
42 + and added to DT bootargs with the form: <append-rootblock>XX.
43 + Only command line ATAG will be processed, the rest of the ATAGs
44 + sent by bootloader will be ignored.
45 +
46 endchoice
47
48 config CMDLINE
49 --- a/arch/arm/boot/compressed/atags_to_fdt.c
50 +++ b/arch/arm/boot/compressed/atags_to_fdt.c
51 @@ -3,6 +3,8 @@
52
53 #if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND)
54 #define do_extend_cmdline 1
55 +#elif defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
56 +#define do_extend_cmdline 1
57 #else
58 #define do_extend_cmdline 0
59 #endif
60 @@ -66,6 +68,65 @@ static uint32_t get_cell_size(const void
61 return cell_size;
62 }
63
64 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
65 +
66 +static char *append_rootblock(char *dest, const char *str, int len, void *fdt)
67 +{
68 + char *ptr, *end;
69 + char *root="root=";
70 + int i, l;
71 + const char *rootblock;
72 +
73 + //ARM doesn't have __HAVE_ARCH_STRSTR, so search manually
74 + ptr = str - 1;
75 +
76 + do {
77 + //first find an 'r' at the begining or after a space
78 + do {
79 + ptr++;
80 + ptr = strchr(ptr, 'r');
81 + if(!ptr) return dest;
82 +
83 + } while (ptr != str && *(ptr-1) != ' ');
84 +
85 + //then check for the rest
86 + for(i = 1; i <= 4; i++)
87 + if(*(ptr+i) != *(root+i)) break;
88 +
89 + } while (i != 5);
90 +
91 + end = strchr(ptr, ' ');
92 + end = end ? (end - 1) : (strchr(ptr, 0) - 1);
93 +
94 + //find partition number (assumes format root=/dev/mtdXX | /dev/mtdblockXX | yy:XX )
95 + for( i = 0; end >= ptr && *end >= '0' && *end <= '9'; end--, i++);
96 + ptr = end + 1;
97 +
98 + /* if append-rootblock property is set use it to append to command line */
99 + rootblock = getprop(fdt, "/chosen", "append-rootblock", &l);
100 + if(rootblock != NULL) {
101 + if(*dest != ' ') {
102 + *dest = ' ';
103 + dest++;
104 + len++;
105 + }
106 + if (len + l + i <= COMMAND_LINE_SIZE) {
107 + memcpy(dest, rootblock, l);
108 + dest += l - 1;
109 + memcpy(dest, ptr, i);
110 + dest += i;
111 + }
112 + } else {
113 + len = strlen(str);
114 + if (len + 1 < COMMAND_LINE_SIZE) {
115 + memcpy(dest, str, len);
116 + dest += len;
117 + }
118 + }
119 + return dest;
120 +}
121 +#endif
122 +
123 static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline)
124 {
125 char cmdline[COMMAND_LINE_SIZE];
126 @@ -85,12 +140,21 @@ static void merge_fdt_bootargs(void *fdt
127
128 /* and append the ATAG_CMDLINE */
129 if (fdt_cmdline) {
130 +
131 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
132 + //save original bootloader args
133 + //and append ubi.mtd with root partition number to current cmdline
134 + setprop_string(fdt, "/chosen", "bootloader-args", fdt_cmdline);
135 + ptr = append_rootblock(ptr, fdt_cmdline, len, fdt);
136 +
137 +#else
138 len = strlen(fdt_cmdline);
139 if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) {
140 *ptr++ = ' ';
141 memcpy(ptr, fdt_cmdline, len);
142 ptr += len;
143 }
144 +#endif
145 }
146 *ptr = '\0';
147
148 @@ -147,7 +211,9 @@ int atags_to_fdt(void *atag_list, void *
149 else
150 setprop_string(fdt, "/chosen", "bootargs",
151 atag->u.cmdline.cmdline);
152 - } else if (atag->hdr.tag == ATAG_MEM) {
153 + }
154 +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
155 + else if (atag->hdr.tag == ATAG_MEM) {
156 if (memcount >= sizeof(mem_reg_property)/4)
157 continue;
158 if (!atag->u.mem.size)
159 @@ -186,6 +252,10 @@ int atags_to_fdt(void *atag_list, void *
160 setprop(fdt, "/memory", "reg", mem_reg_property,
161 4 * memcount * memsize);
162 }
163 +#else
164 +
165 + }
166 +#endif
167
168 return fdt_pack(fdt);
169 }
170 --- a/init/main.c
171 +++ b/init/main.c
172 @@ -89,6 +89,10 @@
173 #include <asm/sections.h>
174 #include <asm/cacheflush.h>
175
176 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
177 +#include <linux/of.h>
178 +#endif
179 +
180 static int kernel_init(void *);
181
182 extern void init_IRQ(void);
183 @@ -540,6 +544,18 @@ asmlinkage __visible void __init start_k
184 page_alloc_init();
185
186 pr_notice("Kernel command line: %s\n", boot_command_line);
187 +
188 +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
189 + //Show bootloader's original command line for reference
190 + if(of_chosen) {
191 + const char *prop = of_get_property(of_chosen, "bootloader-args", NULL);
192 + if(prop)
193 + pr_notice("Bootloader command line (ignored): %s\n", prop);
194 + else
195 + pr_notice("Bootloader command line not present\n");
196 + }
197 +#endif
198 +
199 parse_early_param();
200 after_dashes = parse_args("Booting kernel",
201 static_command_line, __start___param,