From 59ed9413533897823bcdb4c79fd2904718e25b0a Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Thu, 16 Jan 2014 15:01:24 +0530 Subject: [PATCH] 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 --- arch/arc/Kconfig | 11 ----------- arch/arc/kernel/head.S | 26 +++++++------------------- arch/arc/kernel/setup.c | 39 +++++++++++++++++++++++++++------------ 3 files changed, 34 insertions(+), 42 deletions(-) diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index 9063ae6..c1f76f7 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 2c878e9..9919972 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 643eae4..ffb60b4 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; -- 2.7.4