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authorMichal Simek <monstr@monstr.eu>2012-08-16 15:53:35 +0200
committerMichal Simek <monstr@monstr.eu>2012-10-04 14:59:19 +0200
commitfcc1c0ff2506cab8c3a019374550f68b3cbadcbe (patch)
tree5e78312ddff66318a7cd38fcaa92e48b7baaf5da /arch/microblaze/kernel
parentc7e9a211e22782af5857d265a83abf55619f19ea (diff)
downloadlinux-linaro-stable-fcc1c0ff2506cab8c3a019374550f68b3cbadcbe.tar.gz
microblaze: Fix bug with passing command line
When u-boot passes control over to Linux it places the Linux command line between to the end of __init_end. When space between __init_end and __bss_start is not COMMAND_LINE_SIZE then the part of cmdline can be lost. In extreme case if __init_end == __bss_start u-boot can't pass any cmdline to Linux kernel. This patch fix this issue by copying cmd line directly to cmd_line char array which is placed in data section. Reported-by: David Mc Andrew <david.mcandrew@xilinx.com> Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/kernel')
-rw-r--r--arch/microblaze/kernel/head.S14
-rw-r--r--arch/microblaze/kernel/setup.c13
2 files changed, 15 insertions, 12 deletions
diff --git a/arch/microblaze/kernel/head.S b/arch/microblaze/kernel/head.S
index 98b17f9f904b..eef84de5e8c8 100644
--- a/arch/microblaze/kernel/head.S
+++ b/arch/microblaze/kernel/head.S
@@ -109,20 +109,24 @@ no_fdt_arg:
#ifndef CONFIG_CMDLINE_BOOL
/*
* handling command line
- * copy command line to __init_end. There is space for storing command line.
+ * copy command line directly to cmd_line placed in data section.
*/
+ beqid r5, skip /* Skip if NULL pointer */
or r6, r0, r0 /* incremment */
- ori r4, r0, __init_end /* load address of command line */
+ ori r4, r0, cmd_line /* load address of command line */
tophys(r4,r4) /* convert to phys address */
ori r3, r0, COMMAND_LINE_SIZE - 1 /* number of loops */
_copy_command_line:
- lbu r2, r5, r6 /* r2=r5+r6 - r5 contain pointer to command line */
- sb r2, r4, r6 /* addr[r4+r6]= r2*/
+ /* r2=r5+r6 - r5 contain pointer to command line */
+ lbu r2, r5, r6
+ beqid r2, skip /* Skip if no data */
+ sb r2, r4, r6 /* addr[r4+r6]= r2*/
addik r6, r6, 1 /* increment counting */
bgtid r3, _copy_command_line /* loop for all entries */
- addik r3, r3, -1 /* descrement loop */
+ addik r3, r3, -1 /* decrement loop */
addik r5, r4, 0 /* add new space for command line */
tovirt(r5,r5)
+skip:
#endif /* CONFIG_CMDLINE_BOOL */
#ifdef NOT_COMPILE
diff --git a/arch/microblaze/kernel/setup.c b/arch/microblaze/kernel/setup.c
index 4da971d4392f..9dbc9ecb28f1 100644
--- a/arch/microblaze/kernel/setup.c
+++ b/arch/microblaze/kernel/setup.c
@@ -40,7 +40,12 @@ DEFINE_PER_CPU(unsigned int, R11_SAVE); /* Temp variable for entry */
DEFINE_PER_CPU(unsigned int, CURRENT_SAVE); /* Saved current pointer */
unsigned int boot_cpuid;
-char cmd_line[COMMAND_LINE_SIZE];
+/*
+ * Placed cmd_line to .data section because can be initialized from
+ * ASM code. Default position is BSS section which is cleared
+ * in machine_early_init().
+ */
+char cmd_line[COMMAND_LINE_SIZE] __attribute__ ((section(".data")));
void __init setup_arch(char **cmdline_p)
{
@@ -130,12 +135,6 @@ void __init machine_early_init(const char *cmdline, unsigned int ram,
memset(__bss_start, 0, __bss_stop-__bss_start);
memset(_ssbss, 0, _esbss-_ssbss);
- /* Copy command line passed from bootloader */
-#ifndef CONFIG_CMDLINE_BOOL
- if (cmdline && cmdline[0] != '\0')
- strlcpy(cmd_line, cmdline, COMMAND_LINE_SIZE);
-#endif
-
lockdep_init();
/* initialize device tree for usage in early_printk */