[U-Boot] [PATCH] mkimage: fit: spl: Add an optional static offset for external data
Simon Glass
sjg at chromium.org
Thu May 19 05:59:13 CEST 2016
Hi Teddy,
On 2 May 2016 at 02:40, Teddy Reed <teddy.reed at gmail.com> wrote:
> Hey Simon!
>
> On Sun, May 1, 2016 at 12:32 PM, Simon Glass <sjg at chromium.org> wrote:
>> Hi Teddy,
>>
>> On 1 May 2016 at 11:10, Teddy Reed <teddy.reed at gmail.com> wrote:
>>> When building a FIT with external data (-E), an SPL may require absolute
>>> positioning for executing the external firmware. To acheive this use the
>>> (-p) switch which will replace the amended "data-offset" with "data-position"
>>> indicating the absolute position of external data.
>>>
>>> It is considered an error if the requested absolute position overlaps with the
>>> initial data required for the compact FIT.
>>
>> Can you explain why this is useful? I'd like to understand that
>> clearly for your use case.
>
> Sure! I'm working with a board (not in upstream :/ yet), and trying to
> morph the boot to use a verified-boot from SPL. The *only* thing I
> need the SPL to do is read a FIT, check signatures of hashes, then
> jump without arguments to the U-Boot-- no dtb selection, DRAM
> initialization, or anything fancy is needed. Furthermore, I'd like the
> U-Boot build not to depend on the SPL boot, this makes the transition
> from pure-U-Boot-boot to SPL much easier. At the end of the day,
> U-Boot is essentially booting from memory, built that way too, where
> the TEXT_BASE during build is the location I'm placing it outside of
> the FIT. A static 32kB offset on the media.
OK I see.
>
>>
>> I have considered this as a general feature, but I was thinking of
>> being more explicit, e.g. add a property like:
>>
>> data-source
>> - source of data, valid values are:
>> - "internal" - internal to the FIT, with data-offset providing
>> the offset from the start of the FIT to the data
>> - "device" - a separate device, details in property TBD
>> - "address" - a memory address
>>
>> What do you think?
>>
>
> I like this a lot! In fact, for my board I don't need "data-position",
> since the concurrent SPL/U-Boot build know the configured 32kB offset.
> I added the mutex on "data-offset" and "data-position" for some sanity
> when reading back the generated FIT and hopefully so that others could
> benefit from parse-time discovery of static positional offsets.
>
> Having internal, device, address, (maybe offset too) works for me!
>
>> Also can you please update the docs? See uImage.FIT and the mkimage man page.
>>
>
> If you'd like to continue moving forward in trying to land this patch
> I can make revisions and include docs + stderr help.
>
> Let me know!
Sounds good to me, yes.
Regards,
Simon
>
>>>
>>> Signed-off-by: Teddy Reed <teddy.reed at gmail.com>
>>> Cc: Simon Glass <sjg at chromium.org>
>>> ---
>>> tools/fit_image.c | 19 ++++++++++++++++++-
>>> tools/imagetool.h | 1 +
>>> tools/mkimage.c | 9 ++++++++-
>>> 3 files changed, 27 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/tools/fit_image.c b/tools/fit_image.c
>>> index ddefa72..98610bf 100644
>>> --- a/tools/fit_image.c
>>> +++ b/tools/fit_image.c
>>> @@ -417,7 +417,13 @@ static int fit_extract_data(struct image_tool_params *params, const char *fname)
>>> ret = -EPERM;
>>> goto err_munmap;
>>> }
>>> - fdt_setprop_u32(fdt, node, "data-offset", buf_ptr);
>>> + if (params->external_offset > 0) {
>>> + /* An external offset positions the data absolutely. */
>>> + fdt_setprop_u32(fdt, node, "data-position",
>>> + params->external_offset + buf_ptr);
>>> + } else {
>>> + fdt_setprop_u32(fdt, node, "data-offset", buf_ptr);
>>> + }
>>> fdt_setprop_u32(fdt, node, "data-size", len);
>>>
>>> buf_ptr += (len + 3) & ~3;
>>> @@ -438,6 +444,17 @@ static int fit_extract_data(struct image_tool_params *params, const char *fname)
>>> ret = -EIO;
>>> goto err;
>>> }
>>> +
>>> + /* Check if an offset for the external data was set. */
>>> + if (params->external_offset > 0) {
>>> + if (params->external_offset < new_size) {
>>> + debug("External offset %x overlaps FIT length %x",
>>> + params->external_offset, new_size);
>>> + ret = -EINVAL;
>>> + goto err;
>>> + }
>>> + new_size = params->external_offset;
>>> + }
>>> if (lseek(fd, new_size, SEEK_SET) < 0) {
>>> debug("%s: Failed to seek to end of file: %s\n", __func__,
>>> strerror(errno));
>>> diff --git a/tools/imagetool.h b/tools/imagetool.h
>>> index 24f8f4b..7862fa3 100644
>>> --- a/tools/imagetool.h
>>> +++ b/tools/imagetool.h
>>> @@ -73,6 +73,7 @@ struct image_tool_params {
>>> struct content_info *content_head; /* List of files to include */
>>> struct content_info *content_tail;
>>> bool external_data; /* Store data outside the FIT */
>>> + unsigned int external_offset; /* Add padding to external data */
>>> };
>>>
>>> /*
>>> diff --git a/tools/mkimage.c b/tools/mkimage.c
>>> index 2931783..85e4781 100644
>>> --- a/tools/mkimage.c
>>> +++ b/tools/mkimage.c
>>> @@ -138,7 +138,7 @@ static void process_args(int argc, char **argv)
>>>
>>> expecting = IH_TYPE_COUNT; /* Unknown */
>>> while ((opt = getopt(argc, argv,
>>> - "-a:A:bcC:d:D:e:Ef:Fk:K:ln:O:rR:sT:vVx")) != -1) {
>>> + "-a:A:bcC:d:D:e:Ef:Fk:K:ln:p:O:rR:sT:vVx")) != -1) {
>>> switch (opt) {
>>> case 'a':
>>> params.addr = strtoull(optarg, &ptr, 16);
>>> @@ -213,6 +213,13 @@ static void process_args(int argc, char **argv)
>>> if (params.os < 0)
>>> usage("Invalid operating system");
>>> break;
>>> + case 'p':
>>> + params.external_offset = strtoull(optarg, &ptr, 16);
>>> + if (*ptr) {
>>> + fprintf(stderr, "%s: invalid offset size %s\n",
>>> + params.cmdname, optarg);
>>> + exit(EXIT_FAILURE);
>>> + }
>>> case 'r':
>>> params.require_keys = 1;
>>> break;
>>> --
>>> 1.9.1
>>
>
> Thanks!
> --
> Teddy Reed V
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