oxnas: allow booting with legacy loaders

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

4 files changed, 387 insertions, 23 deletions

diff --git a/target/linux/oxnas/config-4.1 b/target/linux/oxnas/config-4.1
index 0f3d798..137f3c3 100644
--- a/target/linux/oxnas/config-4.1
+++ b/target/linux/oxnas/config-4.1
@@ -23,6 +23,11 @@ CONFIG_ARCH_WANT_GENERAL_HUGETLB=y
 CONFIG_ARCH_WANT_IPC_PARSE_VERSION=y
 CONFIG_ARCH_WANT_LIBATA_LEDS=y
 CONFIG_ARM=y
+CONFIG_ARM_APPENDED_DTB=y
+CONFIG_ARM_ATAG_DTB_COMPAT=y
+# CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND is not set
+# CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER is not set
+CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE=y
 CONFIG_ARM_CPUIDLE=y
 # CONFIG_ARM_CPU_SUSPEND is not set
 CONFIG_ARM_DMA_IOMMU_ALIGNMENT=8
@@ -51,7 +56,6 @@ CONFIG_CLKSRC_RPS_TIMER=y
 CONFIG_CLONE_BACKWARDS=y
 CONFIG_CMDLINE="console=ttyS0,115200n8 earlyprintk=serial"
 CONFIG_COMMON_CLK=y
-# CONFIG_COMMON_CLK_PWM is not set
 CONFIG_COMPACTION=y
 CONFIG_CONSOLE_POLL=y
 CONFIG_COREDUMP=y
@@ -79,6 +83,8 @@ CONFIG_CRC16=y
 CONFIG_CRC32_SLICEBY8=y
 CONFIG_CRYPTO_DEFLATE=y
 CONFIG_CRYPTO_LZO=y
+CONFIG_CRYPTO_RNG2=y
+CONFIG_CRYPTO_WORKQUEUE=y
 CONFIG_CRYPTO_XZ=y
 CONFIG_DCACHE_WORD_ACCESS=y
 CONFIG_DEBUG_ICEDCC=y
@@ -86,6 +92,7 @@ CONFIG_DEBUG_LL=y
 CONFIG_DEBUG_LL_INCLUDE="debug/icedcc.S"
 # CONFIG_DEBUG_UART_8250 is not set
 # CONFIG_DEBUG_USER is not set
+# CONFIG_DEFAULT_CFQ is not set
 CONFIG_DEFAULT_HUNG_TASK_TIMEOUT=16
 CONFIG_DETECT_HUNG_TASK=y
 CONFIG_DIRECT_IO=y
@@ -173,7 +180,6 @@ CONFIG_HAVE_SYSCALL_TRACEPOINTS=y
 CONFIG_HAVE_UID16=y
 CONFIG_HAVE_VIRT_CPU_ACCOUNTING_GEN=y
 CONFIG_HOTPLUG_CPU=y
-# CONFIG_HSU_DMA_PCI is not set
 CONFIG_HZ_FIXED=0
 CONFIG_I2C=y
 CONFIG_I2C_ALGOBIT=y
@@ -187,6 +193,7 @@ CONFIG_IOMMU_IO_PGTABLE=y
 CONFIG_IOMMU_IO_PGTABLE_LPAE=y
 # CONFIG_IOMMU_IO_PGTABLE_LPAE_SELFTEST is not set
 CONFIG_IOMMU_SUPPORT=y
+CONFIG_IOSCHED_CFQ=y
 # CONFIG_IP_ADVANCED_ROUTER is not set
 # CONFIG_IP_MULTICAST is not set
 CONFIG_IP_PNP=y
@@ -279,7 +286,6 @@ CONFIG_PCIEASPM_DEFAULT=y
 # CONFIG_PCIEASPM_PERFORMANCE is not set
 # CONFIG_PCIEASPM_POWERSAVE is not set
 CONFIG_PCIEPORTBUS=y
-# CONFIG_PCIE_IPROC is not set
 CONFIG_PCIE_PME=y
 # CONFIG_PCI_DOMAINS_GENERIC is not set
 CONFIG_PCI_OXNAS=y
@@ -295,16 +301,12 @@ CONFIG_PM_CLK=y
 CONFIG_POWER_RESET=y
 # CONFIG_POWER_RESET_BRCMSTB is not set
 CONFIG_POWER_RESET_GPIO=y
-# CONFIG_POWER_RESET_GPIO_RESTART is not set
-# CONFIG_POWER_RESET_LTC2952 is not set
-# CONFIG_POWER_RESET_SYSCON is not set
 CONFIG_POWER_RESET_SYSCON_POWEROFF=y
 CONFIG_POWER_SUPPLY=y
 CONFIG_PPS=y
 CONFIG_PRINTK_TIME=y
 CONFIG_PTP_1588_CLOCK=y
 CONFIG_PWM=y
-# CONFIG_PWM_FSL_FTM is not set
 CONFIG_PWM_SYSFS=y
 CONFIG_RAS=y
 CONFIG_RATIONAL=y
diff --git a/target/linux/oxnas/config-4.4 b/target/linux/oxnas/config-4.4
index 23b20de..c281231 100644
--- a/target/linux/oxnas/config-4.4
+++ b/target/linux/oxnas/config-4.4
@@ -23,6 +23,11 @@ CONFIG_ARCH_WANT_GENERAL_HUGETLB=y
 CONFIG_ARCH_WANT_IPC_PARSE_VERSION=y
 CONFIG_ARCH_WANT_LIBATA_LEDS=y
 CONFIG_ARM=y
+CONFIG_ARM_APPENDED_DTB=y
+CONFIG_ARM_ATAG_DTB_COMPAT=y
+# CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND is not set
+# CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER is not set
+CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE=y
 CONFIG_ARM_CPUIDLE=y
 # CONFIG_ARM_CPU_SUSPEND is not set
 CONFIG_ARM_DMA_IOMMU_ALIGNMENT=8
@@ -35,6 +40,7 @@ CONFIG_ARM_SMMU=y
 CONFIG_ARM_THUMB=y
 CONFIG_ARM_UNWIND=y
 CONFIG_ATA_LEDS=y
+CONFIG_ATAGS=y
 CONFIG_AUTO_ZRELADDR=y
 # CONFIG_BLK_DEV_INITRD is not set
 CONFIG_BLK_DEV_SD=y
@@ -50,6 +56,7 @@ CONFIG_CLKSRC_PROBE=y
 CONFIG_CLKSRC_RPS_TIMER=y
 CONFIG_CLONE_BACKWARDS=y
 CONFIG_CMDLINE="console=ttyS0,115200n8 earlyprintk=serial"
+CONFIG_CMDLINE_FROM_BOOTLOADER=y
 CONFIG_COMMON_CLK=y
 CONFIG_COMPACTION=y
 CONFIG_CONSOLE_POLL=y
@@ -89,6 +96,7 @@ CONFIG_DEBUG_LL_INCLUDE="debug/icedcc.S"
 # CONFIG_DEBUG_UART_8250 is not set
 # CONFIG_DEBUG_USER is not set
 CONFIG_DEFAULT_HUNG_TASK_TIMEOUT=16
+CONFIG_DEPRECATED_PARAM_STRUCT=y
 CONFIG_DETECT_HUNG_TASK=y
 CONFIG_DIRECT_IO=y
 CONFIG_DMADEVICES=y
@@ -100,13 +108,7 @@ CONFIG_DNOTIFY=y
 CONFIG_DTC=y
 CONFIG_DT_IDLE_STATES=y
 CONFIG_DWMAC_GENERIC=y
-# CONFIG_DWMAC_IPQ806X is not set
-# CONFIG_DWMAC_LPC18XX is not set
-# CONFIG_DWMAC_MESON is not set
 CONFIG_DWMAC_OXNAS=y
-# CONFIG_DWMAC_ROCKCHIP is not set
-# CONFIG_DWMAC_SOCFPGA is not set
-# CONFIG_DWMAC_STI is not set
 # CONFIG_DWMAC_SUNXI is not set
 # CONFIG_DW_DMAC_PCI is not set
 CONFIG_EARLY_PRINTK=y
@@ -167,11 +169,6 @@ CONFIG_HAVE_FUNCTION_TRACER=y
 CONFIG_HAVE_GENERIC_DMA_COHERENT=y
 CONFIG_HAVE_IDE=y
 CONFIG_HAVE_IRQ_TIME_ACCOUNTING=y
-CONFIG_HAVE_KERNEL_GZIP=y
-CONFIG_HAVE_KERNEL_LZ4=y
-CONFIG_HAVE_KERNEL_LZMA=y
-CONFIG_HAVE_KERNEL_LZO=y
-CONFIG_HAVE_KERNEL_XZ=y
 CONFIG_HAVE_MEMBLOCK=y
 CONFIG_HAVE_MOD_ARCH_SPECIFIC=y
 CONFIG_HAVE_NET_DSA=y
@@ -229,8 +226,6 @@ CONFIG_LDM_PARTITION=y
 CONFIG_LIBFDT=y
 CONFIG_LOCKUP_DETECTOR=y
 CONFIG_LOCK_SPIN_ON_OWNER=y
-CONFIG_LZ4_COMPRESS=y
-CONFIG_LZ4_DECOMPRESS=y
 CONFIG_LZO_COMPRESS=y
 CONFIG_LZO_DECOMPRESS=y
 CONFIG_MACH_OX820=y
@@ -305,7 +300,6 @@ CONFIG_PM=y
 CONFIG_PM_CLK=y
 # CONFIG_PM_DEBUG is not set
 CONFIG_POWER_RESET=y
-# CONFIG_POWER_RESET_BRCMSTB is not set
 CONFIG_POWER_RESET_GPIO=y
 CONFIG_POWER_RESET_SYSCON_POWEROFF=y
 CONFIG_POWER_SUPPLY=y
@@ -339,14 +333,12 @@ CONFIG_SERIAL_8250_PCI=y
 CONFIG_SERIAL_8250_RUNTIME_UARTS=1
 # CONFIG_SERIAL_KGDB_NMI is not set
 CONFIG_SERIAL_OF_PLATFORM=y
-# CONFIG_SG_SPLIT is not set
 CONFIG_SMP=y
 CONFIG_SMP_ON_UP=y
 CONFIG_SRCU=y
 CONFIG_STMMAC_ETH=y
 CONFIG_STMMAC_PLATFORM=y
 # CONFIG_STRIP_ASM_SYMS is not set
-# CONFIG_SUNXI_SRAM is not set
 CONFIG_SWIOTLB=y
 CONFIG_SYS_SUPPORTS_APM_EMULATION=y
 CONFIG_TREE_RCU=y
diff --git a/target/linux/oxnas/patches-4.1/996-ATAG_DTB_COMPAT_CMDLINE_MANGLE.patch b/target/linux/oxnas/patches-4.1/996-ATAG_DTB_COMPAT_CMDLINE_MANGLE.patch
new file mode 100644
index 0000000..be15ec4
--- /dev/null
+++ b/target/linux/oxnas/patches-4.1/996-ATAG_DTB_COMPAT_CMDLINE_MANGLE.patch
@@ -0,0 +1,185 @@
+Author: Adrian Panella <ianchi74@outlook.com>
+Date:   Fri Jun 10 19:10:15 2016 -0500
+
+generic: Mangle bootloader's kernel arguments
+
+The command-line arguments provided by the boot loader will be
+appended to a new device tree property: bootloader-args.
+If there is a property "append-rootblock" in DT under /chosen
+and a root= option in bootloaders command line it will be parsed
+and added to DT bootargs with the form: <append-rootblock>XX.
+Only command line ATAG will be processed, the rest of the ATAGs
+sent by bootloader will be ignored.
+This is usefull in dual boot systems, to get the current root partition
+without afecting the rest of the system.
+
+
+Signed-off-by: Adrian Panella <ianchi74@outlook.com>
+
+--- a/arch/arm/Kconfig
++++ b/arch/arm/Kconfig
+@@ -1928,6 +1928,17 @@ config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEN
+ 	  The command-line arguments provided by the boot loader will be
+ 	  appended to the the device tree bootargs property.
+ 
++config ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
++	bool "Append rootblock parsing bootloader's kernel arguments"
++	help
++	  The command-line arguments provided by the boot loader will be
++	  appended to a new device tree property: bootloader-args.
++	  If there is a property "append-rootblock" in DT under /chosen 
++	  and a root= option in bootloaders command line it will be parsed 
++	  and added to DT bootargs with the form: <append-rootblock>XX.
++	  Only command line ATAG will be processed, the rest of the ATAGs
++	  sent by bootloader will be ignored.
++
+ endchoice
+ 
+ config CMDLINE
+--- a/arch/arm/boot/compressed/atags_to_fdt.c
++++ b/arch/arm/boot/compressed/atags_to_fdt.c
+@@ -3,6 +3,8 @@
+ 
+ #if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND)
+ #define do_extend_cmdline 1
++#elif defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
++#define do_extend_cmdline 1
+ #else
+ #define do_extend_cmdline 0
+ #endif
+@@ -66,6 +68,59 @@ static uint32_t get_cell_size(const void
+ 	return cell_size;
+ }
+ 
++#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
++
++static char *append_rootblock(char *dest, const char *str, int len, void *fdt)
++{
++	char *ptr, *end;
++	char *root="root=";
++	int i, l;
++	const char *rootblock;
++
++	//ARM doesn't have __HAVE_ARCH_STRSTR, so search manually
++	ptr = str - 1;
++
++	do {
++		//first find an 'r' at the begining or after a space
++		do {
++			ptr++;
++			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;
++
++	/* if append-rootblock property is set use it to append to command line */
++	rootblock = getprop(fdt, "/chosen", "append-rootblock", &l);
++	if(rootblock != NULL) {
++		if(*dest != ' ') {
++			*dest = ' ';
++			dest++;
++			len++;
++		}
++		if (len + l + i <= COMMAND_LINE_SIZE) {
++			memcpy(dest, rootblock, l);
++			dest += l - 1;
++			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];
+@@ -85,12 +140,21 @@ static void merge_fdt_bootargs(void *fdt
+ 
+ 	/* and append the ATAG_CMDLINE */
+ 	if (fdt_cmdline) {
++
++#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
++		//save original bootloader args
++		//and append ubi.mtd with root partition number to current cmdline
++		setprop_string(fdt, "/chosen", "bootloader-args", fdt_cmdline);
++		ptr = append_rootblock(ptr, fdt_cmdline, len, fdt);
++
++#else
+ 		len = strlen(fdt_cmdline);
+ 		if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) {
+ 			*ptr++ = ' ';
+ 			memcpy(ptr, fdt_cmdline, len);
+ 			ptr += len;
+ 		}
++#endif
+ 	}
+ 	*ptr = '\0';
+ 
+@@ -147,7 +211,9 @@ int atags_to_fdt(void *atag_list, void *
+ 			else
+ 				setprop_string(fdt, "/chosen", "bootargs",
+ 					       atag->u.cmdline.cmdline);
+-		} else if (atag->hdr.tag == ATAG_MEM) {
++		}
++#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
++		else if (atag->hdr.tag == ATAG_MEM) {
+ 			if (memcount >= sizeof(mem_reg_property)/4)
+ 				continue;
+ 			if (!atag->u.mem.size)
+@@ -186,6 +252,10 @@ int atags_to_fdt(void *atag_list, void *
+ 		setprop(fdt, "/memory", "reg", mem_reg_property,
+ 			4 * memcount * memsize);
+ 	}
++#else
++
++	}
++#endif
+ 
+ 	return fdt_pack(fdt);
+ }
+--- a/init/main.c
++++ b/init/main.c
+@@ -88,6 +88,10 @@
+ #include <asm/sections.h>
+ #include <asm/cacheflush.h>
+ 
++#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
++#include <linux/of.h>
++#endif
++
+ static int kernel_init(void *);
+ 
+ extern void init_IRQ(void);
+@@ -560,6 +564,18 @@ asmlinkage __visible void __init start_k
+ 	page_alloc_init();
+ 
+ 	pr_notice("Kernel command line: %s\n", boot_command_line);
++
++#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
++	//Show bootloader's original command line for reference
++	if(of_chosen) {
++		const char *prop = of_get_property(of_chosen, "bootloader-args", NULL);
++		if(prop)
++			pr_notice("Bootloader command line (ignored): %s\n", prop);
++		else
++			pr_notice("Bootloader command line not present\n");
++	}
++#endif
++
+ 	parse_early_param();
+ 	after_dashes = parse_args("Booting kernel",
+ 				  static_command_line, __start___param,
diff --git a/target/linux/oxnas/patches-4.4/996-ATAG_DTB_COMPAT_CMDLINE_MANGLE.patch b/target/linux/oxnas/patches-4.4/996-ATAG_DTB_COMPAT_CMDLINE_MANGLE.patch
new file mode 100644
index 0000000..be15ec4
--- /dev/null
+++ b/target/linux/oxnas/patches-4.4/996-ATAG_DTB_COMPAT_CMDLINE_MANGLE.patch
@@ -0,0 +1,185 @@
+Author: Adrian Panella <ianchi74@outlook.com>
+Date:   Fri Jun 10 19:10:15 2016 -0500
+
+generic: Mangle bootloader's kernel arguments
+
+The command-line arguments provided by the boot loader will be
+appended to a new device tree property: bootloader-args.
+If there is a property "append-rootblock" in DT under /chosen
+and a root= option in bootloaders command line it will be parsed
+and added to DT bootargs with the form: <append-rootblock>XX.
+Only command line ATAG will be processed, the rest of the ATAGs
+sent by bootloader will be ignored.
+This is usefull in dual boot systems, to get the current root partition
+without afecting the rest of the system.
+
+
+Signed-off-by: Adrian Panella <ianchi74@outlook.com>
+
+--- a/arch/arm/Kconfig
++++ b/arch/arm/Kconfig
+@@ -1928,6 +1928,17 @@ config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEN
+ 	  The command-line arguments provided by the boot loader will be
+ 	  appended to the the device tree bootargs property.
+ 
++config ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
++	bool "Append rootblock parsing bootloader's kernel arguments"
++	help
++	  The command-line arguments provided by the boot loader will be
++	  appended to a new device tree property: bootloader-args.
++	  If there is a property "append-rootblock" in DT under /chosen 
++	  and a root= option in bootloaders command line it will be parsed 
++	  and added to DT bootargs with the form: <append-rootblock>XX.
++	  Only command line ATAG will be processed, the rest of the ATAGs
++	  sent by bootloader will be ignored.
++
+ endchoice
+ 
+ config CMDLINE
+--- a/arch/arm/boot/compressed/atags_to_fdt.c
++++ b/arch/arm/boot/compressed/atags_to_fdt.c
+@@ -3,6 +3,8 @@
+ 
+ #if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND)
+ #define do_extend_cmdline 1
++#elif defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
++#define do_extend_cmdline 1
+ #else
+ #define do_extend_cmdline 0
+ #endif
+@@ -66,6 +68,59 @@ static uint32_t get_cell_size(const void
+ 	return cell_size;
+ }
+ 
++#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
++
++static char *append_rootblock(char *dest, const char *str, int len, void *fdt)
++{
++	char *ptr, *end;
++	char *root="root=";
++	int i, l;
++	const char *rootblock;
++
++	//ARM doesn't have __HAVE_ARCH_STRSTR, so search manually
++	ptr = str - 1;
++
++	do {
++		//first find an 'r' at the begining or after a space
++		do {
++			ptr++;
++			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;
++
++	/* if append-rootblock property is set use it to append to command line */
++	rootblock = getprop(fdt, "/chosen", "append-rootblock", &l);
++	if(rootblock != NULL) {
++		if(*dest != ' ') {
++			*dest = ' ';
++			dest++;
++			len++;
++		}
++		if (len + l + i <= COMMAND_LINE_SIZE) {
++			memcpy(dest, rootblock, l);
++			dest += l - 1;
++			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];
+@@ -85,12 +140,21 @@ static void merge_fdt_bootargs(void *fdt
+ 
+ 	/* and append the ATAG_CMDLINE */
+ 	if (fdt_cmdline) {
++
++#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
++		//save original bootloader args
++		//and append ubi.mtd with root partition number to current cmdline
++		setprop_string(fdt, "/chosen", "bootloader-args", fdt_cmdline);
++		ptr = append_rootblock(ptr, fdt_cmdline, len, fdt);
++
++#else
+ 		len = strlen(fdt_cmdline);
+ 		if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) {
+ 			*ptr++ = ' ';
+ 			memcpy(ptr, fdt_cmdline, len);
+ 			ptr += len;
+ 		}
++#endif
+ 	}
+ 	*ptr = '\0';
+ 
+@@ -147,7 +211,9 @@ int atags_to_fdt(void *atag_list, void *
+ 			else
+ 				setprop_string(fdt, "/chosen", "bootargs",
+ 					       atag->u.cmdline.cmdline);
+-		} else if (atag->hdr.tag == ATAG_MEM) {
++		}
++#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE
++		else if (atag->hdr.tag == ATAG_MEM) {
+ 			if (memcount >= sizeof(mem_reg_property)/4)
+ 				continue;
+ 			if (!atag->u.mem.size)
+@@ -186,6 +252,10 @@ int atags_to_fdt(void *atag_list, void *
+ 		setprop(fdt, "/memory", "reg", mem_reg_property,
+ 			4 * memcount * memsize);
+ 	}
++#else
++
++	}
++#endif
+ 
+ 	return fdt_pack(fdt);
+ }
+--- a/init/main.c
++++ b/init/main.c
+@@ -88,6 +88,10 @@
+ #include <asm/sections.h>
+ #include <asm/cacheflush.h>
+ 
++#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
++#include <linux/of.h>
++#endif
++
+ static int kernel_init(void *);
+ 
+ extern void init_IRQ(void);
+@@ -560,6 +564,18 @@ asmlinkage __visible void __init start_k
+ 	page_alloc_init();
+ 
+ 	pr_notice("Kernel command line: %s\n", boot_command_line);
++
++#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE)
++	//Show bootloader's original command line for reference
++	if(of_chosen) {
++		const char *prop = of_get_property(of_chosen, "bootloader-args", NULL);
++		if(prop)
++			pr_notice("Bootloader command line (ignored): %s\n", prop);
++		else
++			pr_notice("Bootloader command line not present\n");
++	}
++#endif
++
+ 	parse_early_param();
+ 	after_dashes = parse_args("Booting kernel",
+ 				  static_command_line, __start___param,