[PATCH 2/5] Introduce binfmt support

[Sascha Hauer]

On Fri, Apr 13, 2012 at 10:02:46AM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote:
> This will allow to execute any file and detect it's type to handle it.
> This will allow to use shell for bootp bootfile or dfu.
> 
> You can register multiple hook for the same filetype. They will be execute
> in the invert order of register. If a hook does not handle the file you just
> return -ERESTARTNOHAND;
> 
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> ---
>  common/Makefile  |    2 +-
>  common/binfmt.c  |   90 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  common/hush.c    |   31 +++++++++++-------
>  include/binfmt.h |   26 +++++++++++++++
>  4 files changed, 136 insertions(+), 13 deletions(-)
>  create mode 100644 common/binfmt.c
>  create mode 100644 include/binfmt.h
> 
> diff --git a/common/Makefile b/common/Makefile
> index 76fe407..d7dbf88 100644
> --- a/common/Makefile
> +++ b/common/Makefile
> @@ -1,4 +1,4 @@
> -obj-$(CONFIG_SHELL_HUSH)	+= hush.o
> +obj-$(CONFIG_SHELL_HUSH)	+= hush.o binfmt.o

Please check compilation with bootm command + simple shell. It will
give you undefined reference to binfmt_register.

> +static LIST_HEAD(binfmt_hooks);
> +
> +static int binfmt_run(char* file, int argc, char** argv)
> +{
> +	struct binfmt_hook* b;

A pointer is like this:

void *something

Not 'void* something' and not 'void * something'. There are all three
variants in this patch.

> +	enum filetype type = file_name_detect_type(file);
> +	int ret;
> +
> +	list_for_each_entry(b, &binfmt_hooks, list) {
> +		if(b->type != type)
> +			continue;
> +
> +		ret = b->hook(b, file, argc, argv);
> +		if (ret != -ERESTARTNOHAND)
> +			return ret;
> +	}
> +	return -ENOENT;
> +}
> +
> +static int binfmt_exec_excute(struct binfmt_hook *b, char* file, int argc, char **argv)
> +{
> +	char ** newargv = xzalloc(sizeof(char*) * (argc + 1));
> +	int ret, i;
> +
> +	newargv[0] = b->exec;
> +
> +	for (i = 1 ; i < argc; i++)
> +		newargv[i] = argv[i];
> +	newargv[i] = file;

It took me some time to see what this does and why it has to do this.
Can you add a comment like:

/*
 * This converts the original '/executable <args>' into
 * 'barebox_cmd <args> /executable'
 */

Sascha

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