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Commit fcc1c0ff authored by Michal Simek's avatar Michal Simek
Browse files

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: default avatarDavid Mc Andrew <david.mcandrew@xilinx.com>
Signed-off-by: default avatarMichal Simek <monstr@monstr.eu>
parent c7e9a211

arch/microblaze/kernel/head.S

+9 −5
Original line number Diff line number Diff line
@@ -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 */

	/* 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

arch/microblaze/kernel/setup.c

+6 −7
Original line number Diff line number Diff line
@@ -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 */