[PATCH] atags_to_fdt: take into account root's #size and #cells

[gregory.clement@free-electrons.com (Gregory CLEMENT)]

On 06/19/2013 12:57 PM, Ben Dooks wrote:
> When creating entries for /memory, the root #size and #cells must be taken
> into account otherwise the node will not be recongnized when the OF code
> scans the nodes.
> 
> On some systems, the default is now to be 2 for each of #size and #cells
> which means that appending a kernrel and having it update from ATAGS does
> not work properly.
Hi Ben,

There is already a fix for it which is applied in Russell King's git tree, see
http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=7722/1

Regards,
> ---
>  arch/arm/boot/compressed/atags_to_fdt.c |   22 +++++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/compressed/atags_to_fdt.c b/arch/arm/boot/compressed/atags_to_fdt.c
> index 74e193e..da36840 100644
> --- a/arch/arm/boot/compressed/atags_to_fdt.c
> +++ b/arch/arm/boot/compressed/atags_to_fdt.c
> @@ -1,5 +1,6 @@
>  #include <asm/setup.h>
>  #include <libfdt.h>
> +#include <linux/of.h>
>  
>  #if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND)
>  #define do_extend_cmdline 1
> @@ -95,9 +96,12 @@ static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline)
>  int atags_to_fdt(void *atag_list, void *fdt, int total_space)
>  {
>  	struct tag *atag = atag_list;
> -	uint32_t mem_reg_property[2 * NR_BANKS];
> +	uint32_t mem_reg_property[2 * 2 * NR_BANKS];
> +	const __be32 *prop;
>  	int memcount = 0;
>  	int ret;
> +	u32 dt_root_size_cells;
> +	u32 dt_root_addr_cells;
>  
>  	/* make sure we've got an aligned pointer */
>  	if ((u32)atag_list & 0x3)
> @@ -118,6 +122,17 @@ int atags_to_fdt(void *atag_list, void *fdt, int total_space)
>  	if (ret < 0)
>  		return ret;
>  
> +	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
> +	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
> +
> +	prop = getprop(fdt, "/", "#size-cells", NULL);
> +	if (prop)
> +		dt_root_size_cells = be32_to_cpup(prop);
> +
> +	prop = getprop(fdt, "/", "#address-cells", NULL);
> +	if (prop)
> +		dt_root_addr_cells = be32_to_cpup(prop);
> +
>  	for_each_tag(atag, atag_list) {
>  		if (atag->hdr.tag == cpu_to_atag32(ATAG_CMDLINE)) {
>  			/* Append the ATAGS command line to the device tree
> @@ -137,7 +152,12 @@ int atags_to_fdt(void *atag_list, void *fdt, int total_space)
>  				continue;
>  			if (!atag32_to_cpu(atag->u.mem.size))
>  				continue;
> +
> +			for (ret = 0; ret < dt_root_addr_cells - 1; ret++)
> +				mem_reg_property[memcount++] = cpu_to_fdt32(0);
>  			mem_reg_property[memcount++] = cpu_to_fdt32(atag32_to_cpu(atag->u.mem.start));
> +			for (ret = 0; ret < dt_root_size_cells - 1; ret++)
> +				mem_reg_property[memcount++] = cpu_to_fdt32(0);
>  			mem_reg_property[memcount++] = cpu_to_fdt32(atag32_to_cpu(atag->u.mem.size));
>  		} else if (atag->hdr.tag == cpu_to_atag32(ATAG_INITRD2)) {
>  			uint32_t initrd_start, initrd_size;
> 


-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com