Re: [RFC 7/8] m68k: mmu: add u-boot command line support in setup_arch()

[Greg Ungerer <gregungerer@westnet.com.au>]

Hi Yannick,

Again no point having two copies of the same code.
Perhaps merging of the _mm and _no setup code makes
more sense now.

Regards
Greg


On 08/07/15 19:51, Yannick GICQUEL wrote:
> This part was ported from setup_no.c
>
> Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
> ---
>   arch/m68k/kernel/setup_mm.c | 80 +++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 80 insertions(+)
>
> diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c
> index 0bc6f77..94be970 100644
> --- a/arch/m68k/kernel/setup_mm.c
> +++ b/arch/m68k/kernel/setup_mm.c
> @@ -225,6 +225,68 @@ static void __init m68k_parse_bootinfo(const struct bi_record *record)
>   #endif
>   }
>
> +#if defined(CONFIG_UBOOT)
> +/*
> + * parse_uboot_commandline
> + *
> + * Copies u-boot commandline arguments and store them in the proper linux
> + * variables.
> + *
> + * Assumes:
> + *	_init_sp global contains the address in the stack pointer when the
> + *	kernel starts (see head.S::_start)
> + *
> + *	U-Boot calling convention:
> + *	(*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
> + *
> + *	_init_sp can be parsed as such
> + *
> + *	_init_sp+00 = u-boot cmd after jsr into kernel (skip)
> + *	_init_sp+04 = &kernel board_info (residual data)
> + *	_init_sp+08 = &initrd_start
> + *	_init_sp+12 = &initrd_end
> + *	_init_sp+16 = &cmd_start
> + *	_init_sp+20 = &cmd_end
> + *
> + *	This also assumes that the memory locations pointed to are still
> + *	unmodified. U-boot places them near the end of external SDRAM.
> + *
> + * Argument(s):
> + *	commandp = the linux commandline arg container to fill.
> + *	size     = the sizeof commandp.
> + *
> + * Returns:
> + */
> +static void __init parse_uboot_commandline(char *commandp, int size)
> +{
> +	extern unsigned long _init_sp;
> +	unsigned long *sp;
> +	unsigned long uboot_kbd;
> +	unsigned long uboot_initrd_start, uboot_initrd_end;
> +	unsigned long uboot_cmd_start, uboot_cmd_end;
> +
> +
> +	sp = (unsigned long *)_init_sp;
> +	uboot_kbd = sp[1];
> +	uboot_initrd_start = sp[2];
> +	uboot_initrd_end = sp[3];
> +	uboot_cmd_start = sp[4];
> +	uboot_cmd_end = sp[5];
> +
> +	if (uboot_cmd_start && uboot_cmd_end)
> +		strncpy(commandp, (const char *)uboot_cmd_start, size);
> +#if defined(CONFIG_BLK_DEV_INITRD)
> +	if (uboot_initrd_start && uboot_initrd_end &&
> +		(uboot_initrd_end > uboot_initrd_start)) {
> +		initrd_start = uboot_initrd_start;
> +		initrd_end = uboot_initrd_end;
> +		printk(KERN_INFO "initrd at 0x%lx:0x%lx\n",
> +			initrd_start, initrd_end);
> +	}
> +#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
> +}
> +#endif /* #if defined(CONFIG_UBOOT) */
> +
>   void __init setup_arch(char **cmdline_p)
>   {
>   #ifndef CONFIG_SUN3
> @@ -274,6 +336,24 @@ void __init setup_arch(char **cmdline_p)
>   	strncpy(m68k_command_line, CONFIG_BOOTPARAM_STRING, CL_SIZE);
>   	m68k_command_line[CL_SIZE - 1] = 0;
>   #endif /* CONFIG_BOOTPARAM */
> +
> +#if defined(CONFIG_UBOOT)
> +	/* CONFIG_UBOOT and CONFIG_BOOTPARAM defined, concatenate cmdline */
> +	#if defined(CONFIG_BOOTPARAM)
> +		/* Add the whitespace separator */
> +		m68k_command_line[strlen(CONFIG_BOOTPARAM_STRING)] = ' ';
> +		/* Parse uboot command line into the rest of the buffer */
> +		parse_uboot_commandline(
> +			&m68k_command_line[(strlen(CONFIG_BOOTPARAM_STRING)+1)],
> +			(sizeof(m68k_command_line) -
> +			(strlen(CONFIG_BOOTPARAM_STRING)+1)));
> +	/* Only CONFIG_UBOOT defined, create cmdline */
> +	#else
> +		parse_uboot_commandline(&m68k_command_line[0], sizeof(m68k_command_line));
> +	#endif /* CONFIG_BOOTPARAM */
> +	m68k_command_line[sizeof(m68k_command_line) - 1] = 0;
> +#endif /* CONFIG_UBOOT */
> +
>   	*cmdline_p = m68k_command_line;
>   	memcpy(boot_command_line, *cmdline_p, CL_SIZE);
>
>