[PATCH RFC] bootm: support printing bootm parameters determined at runtime to file

[Sascha Hauer]

On Wed, Jan 10, 2024 at 03:39:58PM +0100, Ahmad Fatoum wrote:
> The barebox bootm command is often not called directly, but via
> bootloader spec or FIT image boot handlers. For debugging, it can be
> useful to reuse those boot handlers, but replace single artifacts, e.g.
> using the barebox device tree instead of the bootloader-spec provided
> device tree.
> 
> To make this easier, have boot -v -d (verbose + dry run) write a boot
> script that reproduces the cancelled boot to /env/boot/cancelled.

I like the idea very much. I also had this problem more than once.

I think an explicit option rather than "-v -d" would be better. With
this there would be a natural way to document this behaviour in the
boot help output.

/env/boot/cancelled would be saved in the environment with a saveenv
which is likely not desirable. Maybe better put it somewhere in /tmp/?

> +	dprintf(fd, "global.bootm.verify=%s\n", verify);
> +
> +	dprintf(fd, "\n");
> +
> +	if (data->os_address != UIMAGE_SOME_ADDRESS)
> +		dprintf(fd, "global.bootm.image.loadaddr=0x%08lx\n", data->os_address);
> +	if (data->os_file)
> +		dprintf(fd, "global.bootm.image='%s'\n", data->os_file);
> +	if (data->oftree_file)
> +		dprintf(fd, "global.bootm.oftree='%s'\n", data->oftree_file);
> +#ifdef CONFIG_BOOTM_INITRD
> +	if (data->initrd_file)
> +		dprintf(fd, "global.bootm.initrd='%s'\n", data->initrd_file);
> +
> +	if (data->initrd_address != UIMAGE_INVALID_ADDRESS)
> +		dprintf(fd, "global.bootm.initrd.loadaddr=0x%08lx\n", data->initrd_address);
> +#endif
> +	if (data->tee_file)
> +		dprintf(fd, "global.bootm.tee_file='%s'\n", data->tee_file);
> +
> +	dprintf(fd, "\n");
> +
> +	bootargs = linux_bootargs_get();
> +	if (bootargs)
> +		dprintf(fd, "global linux.bootargs.dyn.concatenated='%s'\n", bootargs);

This will contain all of linux.bootargs.* which are then added again
when we actually boot the script, so we end up having many bootargs
twice. This is not very nice, I don't know though how/if we can improve
that.

Sascha

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