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authorVineet Gupta <vgupta@synopsys.com>2014-01-16 15:01:24 +0530
committerVineet Gupta <vgupta@synopsys.com>2014-01-16 18:49:38 +0530
commit59ed9413533897823bcdb4c79fd2904718e25b0a (patch)
treef016337b77b6299e551282c642249ec9327b4784 /arch/arc
parentd8e8c7dda11f5d5cf90495f2e89d917a83509bc0 (diff)
downloadlinux-linaro-stable-59ed9413533897823bcdb4c79fd2904718e25b0a.tar.gz
ARC: [cmdline] uboot cmdline handling rework
* Moved cmdline copy from asm to "C" - allows for more robust checking of pointer validity etc. * Remove the Kconfig option to do so, base it on a runtime value passed by u-boot Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc')
-rw-r--r--arch/arc/Kconfig11
-rw-r--r--arch/arc/kernel/head.S26
-rw-r--r--arch/arc/kernel/setup.c39
3 files changed, 34 insertions, 42 deletions
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 9063ae6553cc..c1f76f7424ac 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -409,17 +409,6 @@ config ARC_DBG_TLB_MISS_COUNT
Counts number of I and D TLB Misses and exports them via Debugfs
The counters can be cleared via Debugfs as well
-config CMDLINE_UBOOT
- bool "Support U-boot kernel command line passing"
- default n
- help
- If you are using U-boot (www.denx.de) and wish to pass the kernel
- command line from the U-boot environment to the Linux kernel then
- switch this option on.
- ARC U-boot will setup the cmdline in RAM/flash and set r2 to point
- to it. kernel startup code will append this to DeviceTree
- /bootargs provided cmdline args.
-
config ARC_BUILTIN_DTB_NAME
string "Built in DTB"
help
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 2c878e964a64..991997269d02 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -49,25 +49,13 @@ stext:
st.ab 0, [r5,4]
brlt r5, r6, 1b
-#ifdef CONFIG_CMDLINE_UBOOT
- ; support for bootloader provided cmdline
- ; If cmdline passed by u-boot, then
- ; r0 = 1 (because ATAGS parsing, now retired, used to use 0)
- ; r1 = magic number (board identity)
- ; r2 = addr of cmdline string (somewhere in memory/flash)
-
- brne r0, 1, .Lother_bootup_chores ; u-boot didn't pass cmdline
- breq r2, 0, .Lother_bootup_chores ; or cmdline is NULL
-
- mov r5, @command_line
-1:
- ldb.ab r6, [r2, 1]
- breq r6, 0, .Lother_bootup_chores
- b.d 1b
- stb.ab r6, [r5, 1]
-#endif
-
-.Lother_bootup_chores:
+ ; Uboot - kernel ABI
+ ; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
+ ; r1 = magic number (board identity, unused as of now
+ ; r2 = pointer to uboot provided cmdline or external DTB in mem
+ ; These are handled later in setup_arch()
+ st r0, [@uboot_tag]
+ st r2, [@uboot_arg]
; Identify if running on ISS vs Silicon
; IDENTITY Reg [ 3 2 1 0 ]
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index 643eae4436e0..ffb60b4f6f86 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -29,7 +29,10 @@
int running_on_hw = 1; /* vs. on ISS */
-char __initdata command_line[COMMAND_LINE_SIZE];
+/* Part of U-boot ABI: see head.S */
+int __initdata uboot_tag;
+char __initdata *uboot_arg;
+
const struct machine_desc *machine_desc;
struct task_struct *_current_task[NR_CPUS]; /* For stack switching */
@@ -311,19 +314,31 @@ void setup_processor(void)
arc_chk_fpu();
}
+static inline int is_kernel(unsigned long addr)
+{
+ if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
+ return 1;
+ return 0;
+}
+
void __init setup_arch(char **cmdline_p)
{
- /* This also populates @boot_command_line from /bootargs */
- machine_desc = setup_machine_fdt(__dtb_start);
- if (!machine_desc)
- panic("Embedded DT invalid\n");
-
- /* Append any u-boot provided cmdline */
-#ifdef CONFIG_CMDLINE_UBOOT
- /* Add a whitespace seperator between the 2 cmdlines */
- strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
- strlcat(boot_command_line, command_line, COMMAND_LINE_SIZE);
-#endif
+ machine_desc = setup_machine_fdt(__dtb_start);
+ if (!machine_desc)
+ panic("Embedded DT invalid\n");
+
+ /*
+ * Append uboot cmdline to embedded DT cmdline.
+ * setup_machine_fdt() would have populated @boot_command_line
+ */
+ if (uboot_tag == 1) {
+ BUG_ON(is_kernel(unsigned long)uboot_arg);
+
+ /* Ensure a whitespace between the 2 cmdlines */
+ strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
+ strlcat(boot_command_line, uboot_arg,
+ COMMAND_LINE_SIZE);
+ }
/* Save unparsed command line copy for /proc/cmdline */
*cmdline_p = boot_command_line;