[OpenWrt-Devel] [PATCH 2/8] bootargs: Add mangled bootargs for ATAG to DTB
Adrian Panella
ianchi74 at outlook.com
Thu Mar 31 21:10:49 EDT 2016
From: Adrian Panella <ianchi74 at outlook.com>
Date: Thu, 17 Mar 2016 22:07:38 -0600
Subject: [PATCH 2/8] bootargs: Add mangled bootargs for ATAG to DTB
Enables reading bootloader supplied bootargs and
append them to the DTB as a new key (bootloader-args), so that
they are known but won't break the automatisms OpenWrt uses.
It appends to the kernel command line the mumber of the mtd partition
that has to be set as root (this is needed for the dual boot mechanism)
using the option mangled_rootblock=XX
Needs the following options to be set in Kernel config
CONFIG_ARM_ATAG_DTB_COMPAT=y
CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND=y
Signed-off-by: Adrian Panella <ianchi74 at outlook.com>
---
.../patches-3.18/100-find_active_root.patch | 61 +++++++++++++++
.../patches-3.18/110-ATAG-mangled-bootargs.patch | 86
++++++++++++++++++++++
target/linux/ipq806x/config-3.18 | 5 ++++-
3 files changed, 151 insertions(+), 1 deletion(-)
create mode 100644
target/linux/ipq806x/patches-3.18/100-find_active_root.patch
create mode 100644
target/linux/ipq806x/patches-3.18/110-ATAG-mangled-bootargs.patch
diff --git a/target/linux/ipq806x/patches-3.18/100-find_active_root.patch
b/target/linux/ipq806x/patches-3.18/100-find_active_root.patch
new file mode 100644
index 0000000..e32b608
--- /dev/null
+++ b/target/linux/ipq806x/patches-3.18/100-find_active_root.patch
@@ -0,0 +1,61 @@
+The WRT1900AC among other Linksys routers uses a dual-firmware layout.
+Dynamically rename the active partition to "ubi".
+
+Signed-off-by: Imre Kaloz <kaloz at openwrt.org>
+
+--- a/drivers/mtd/ofpart.c
++++ b/drivers/mtd/ofpart.c
+@@ -25,12 +25,15 @@ static bool node_has_compatible(struct d
+ return of_get_property(pp, "compatible", NULL);
+ }
+
++static int mangled_rootblock;
++
+ static int parse_ofpart_partitions(struct mtd_info *master,
+ struct mtd_partition **pparts,
+ struct mtd_part_parser_data *data)
+ {
+ struct device_node *node;
+ const char *partname;
++ const char *owrtpart = "ubi";
+ struct device_node *pp;
+ int nr_parts, i;
+
+@@ -78,9 +81,15 @@ static int parse_ofpart_partitions(struc
+ (*pparts)[i].offset = of_read_number(reg, a_cells);
+ (*pparts)[i].size = of_read_number(reg + a_cells, s_cells);
+
+- partname = of_get_property(pp, "label", &len);
+- if (!partname)
+- partname = of_get_property(pp, "name", &len);
++ if (mangled_rootblock && (i == mangled_rootblock)) {
++ partname = owrtpart;
++ } else {
++ partname = of_get_property(pp, "label", &len);
++
++ if (!partname)
++ partname = of_get_property(pp, "name", &len);
++ }
++
+ (*pparts)[i].name = partname;
+
+ if (of_get_property(pp, "read-only", &len))
+@@ -178,6 +187,18 @@ static int __init ofpart_parser_init(voi
+ return 0;
+ }
+
++static int __init active_root(char *str)
++{
++ get_option(&str, &mangled_rootblock);
++
++ if (!mangled_rootblock)
++ return 1;
++
++ return 1;
++}
++
++__setup("mangled_rootblock=", active_root);
++
+ static void __exit ofpart_parser_exit(void)
+ {
+ deregister_mtd_parser(&ofpart_parser);
diff --git
a/target/linux/ipq806x/patches-3.18/110-ATAG-mangled-bootargs.patch
b/target/linux/ipq806x/patches-3.18/110-ATAG-mangled-bootargs.patch
new file mode 100644
index 0000000..34da86c
--- /dev/null
+++ b/target/linux/ipq806x/patches-3.18/110-ATAG-mangled-bootargs.patch
@@ -0,0 +1,86 @@
+--- a/arch/arm/boot/compressed/atags_to_fdt.c
++++ b/arch/arm/boot/compressed/atags_to_fdt.c
+@@ -66,6 +66,55 @@ static uint32_t get_cell_size(const void
+ return cell_size;
+ }
+
++#if defined(CONFIG_MANGLE_BOOTARGS)
++
++static char *append_mangled_root(char *dest, char *str, int len)
++{
++ char *ptr, *end;
++ char *root="root=";
++ int i;
++
++ //ARM doesn't have __HAVE_ARCH_STRSTR, so search manually
++ ptr=str-1;
++
++ do {
++ ptr++;
++ //first find an 'r' at the begining or after a space
++ do {
++ ptr=strchr(ptr, 'r');
++ if(!ptr) return dest;
++
++ } while (ptr!=str && *(ptr-1)!=' ');
++
++ //then check for the rest
++ for(i=1; i<=4;i++)
++ if(*(ptr+i)!=*(root+i)) break;
++
++ } while (i!=5);
++
++
++ end=strchr(ptr, ' ');
++ end= end ? (end-1) : (strchr(ptr, 0)-1);
++
++
++ //find partition number (assumes format root=/dev/mtdXX |
/dev/mtdblockXX | yy:XX)
++ for(i=0;end >= ptr && *end >='0' && *end <='9' ; end--, i++);
++ ptr=end+1;
++
++
++ //append mangled_root=XX
++ len=COMMAND_LINE_SIZE-len ;
++ if (len + 19 + i +1 < COMMAND_LINE_SIZE) {
++ memcpy(dest," mangled_rootblock=", 19);
++ dest+=19;
++ memcpy(dest, ptr, i);
++ dest+=i;
++ }
++
++ return dest;
++}
++#endif
++
+ static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline)
+ {
+ char cmdline[COMMAND_LINE_SIZE];
+@@ -85,16 +134,27 @@ static void merge_fdt_bootargs(void *fdt
+
+ /* and append the ATAG_CMDLINE */
+ if (fdt_cmdline) {
++
++#if defined(CONFIG_MANGLE_BOOTARGS)
++
++ //save original bootloader args
++ //and append mangled_root with root partition number to current
cmdline
++ setprop_string(fdt, "/chosen", "bootloader-args", fdt_cmdline);
++ ptr=append_mangled_root(ptr, fdt_cmdline, len);
++
++#else
+ len = strlen(fdt_cmdline);
+ if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) {
+ *ptr++ = ' ';
+ memcpy(ptr, fdt_cmdline, len);
+ ptr += len;
+ }
++#endif
+ }
+ *ptr = '\0';
+
+ setprop_string(fdt, "/chosen", "bootargs", cmdline);
++
+ }
+
+ /*
diff --git a/target/linux/ipq806x/config-3.18
b/target/linux/ipq806x/config-3.18
index 40e3a75..908f7f1 100644
--- a/target/linux/ipq806x/config-3.18
+++ b/target/linux/ipq806x/config-3.18
@@ -36,7 +36,9 @@ CONFIG_ARM_AMBA=y
CONFIG_ARM_APPENDED_DTB=y
CONFIG_ARM_ARCH_TIMER=y
CONFIG_ARM_ARCH_TIMER_EVTSTREAM=y
-# CONFIG_ARM_ATAG_DTB_COMPAT is not set
+CONFIG_ARM_ATAG_DTB_COMPAT=y
+CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND=y
+# CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER is not set
CONFIG_ARM_CPU_SUSPEND=y
CONFIG_ARM_GIC=y
CONFIG_ARM_HAS_SG_CHAIN=y
@@ -247,6 +249,7 @@ CONFIG_LIBFDT=y
CONFIG_LOCKUP_DETECTOR=y
CONFIG_LZO_COMPRESS=y
CONFIG_LZO_DECOMPRESS=y
+CONFIG_MANGLE_BOOTARGS=y
CONFIG_MDIO_BITBANG=y
CONFIG_MDIO_BOARDINFO=y
CONFIG_MDIO_GPIO=y
--
1.9.1
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