On Wed, Mar 22, 2023 at 11:59:02AM +0100, Frieder Schrempf wrote: > Hi, > > On 07.03.23 21:26, Mathieu Poirier wrote: > > On Sat, Mar 04, 2023 at 03:59:38PM +0800, Peng Fan wrote: > >> > >> > >> On 2/14/2023 1:50 AM, Mathieu Poirier wrote: > >>> On Mon, Feb 13, 2023 at 12:15:59PM +0200, Iuliana Prodan wrote: > >>>> On 2/12/2023 9:43 AM, Peng Fan wrote: > >>>>> Hi Iuliana, > >>>>> > >>>>>> Subject: Re: [PATCH V3 0/6] remoteproc: imx_rproc: support firmware in > >>>>>> DDR > >>>>>> > >>>>>> > >>>>>> On 2/9/2023 8:38 AM, Peng Fan (OSS) wrote: > >>>>>>> From: Peng Fan <peng.fan@xxxxxxx> > >>>>>>> > >>>>>>> V3: > >>>>>>> > >>>>>>> Daniel, Iuliana > >>>>>>> > >>>>>>> Please help review this patchset per Mathieu's comments. > >>>>>>> > >>>>>>> Thanks, > >>>>>>> Peng. > >>>>>>> > >>>>>>> Move patch 3 in v2 to 1st patch in v3 and add Fixes tag Per Daniel > >>>>>>> IMX_RPROC_ANY in patch 3 Per Mathieu > >>>>>>> Update comment and commit log in patch 5, 6. > >>>>>>> > >>>>>>> NXP SDK provides ".interrupts" section, but I am not sure how others > >>>>>>> build the firmware. So I still keep patch 6 as v2, return bootaddr > >>>>>>> if there is no ".interrupts" section. > >>>>>>> > >>>>>>> V2: > >>>>>>> patch 4 is introduced for sparse check warning fix > >>>>>>> > >>>>>>> This pachset is to support i.MX8M and i.MX93 Cortex-M core firmware > >>>>>>> could be in DDR, not just the default TCM. > >>>>>>> > >>>>>>> i.MX8M needs stack/pc value be stored in TCML entry address[0,4], the > >>>>>>> initial value could be got from firmware first section ".interrupts". > >>>>>>> i.MX93 is a bit different, it just needs the address of .interrupts > >>>>>>> section. NXP SDK always has .interrupts section. > >>>>>>> > >>>>>>> So first we need find the .interrupts section from firmware, so patch > >>>>>>> 1 is to reuse the code of find_table to introduce a new API > >>>>>>> rproc_elf_find_shdr to find shdr, the it could reused by i.MX driver. > >>>>>>> > >>>>>>> Patch 2 is introduce devtype for i.MX8M/93 > >>>>>>> > >>>>>>> Although patch 3 is correct the mapping, but this area was never used > >>>>>>> by NXP SW team, we directly use the DDR region, not the alias region. > >>>>>>> Since this patchset is first to support firmware in DDR, mark this > >>>>>>> patch as a fix does not make much sense. > >>>>>>> > >>>>>>> patch 4 and 5 is support i.MX8M/93 firmware in DDR with parsing > >>>>>>> .interrupts section. Detailed information in each patch commit message. > >>>>>>> > >>>>>>> Patches were tested on i.MX8MQ-EVK i.MX8MP-EVK i.MX93-11x11-EVK > >>>>>> If one can build their firmware as they want, then the .interrupt section can > >>>>>> also be called differently. > >>>>>> I don't think is a good idea to base all your implementation on this > >>>>>> assumption. > >>>>>> > >>>>>> It's clear there's a limitation when linking firmware in DDR, so this should be > >>>>>> well documented so one can compile their firmware and put the needed > >>>>>> section (interrupt as we call it in NXP SDK) always in TCML - independently > >>>>>> where the other section go. > >>>>> Ok, so .interrupt section should be a must in elf file if I understand correctly. > >>>>> > >>>>> I could add a check in V4 that if .interrupt section is not there, driver will report > >>>>> failure. > >>>>> > >>>>> How do you think? > >>>> > >>>> Peng, I stand by my opinion that the limitation of linking firmware in DDR > >>>> should be documented in an Application Note, or maybe there are other > >>>> documents where how to use imx_rproc is explained. > >>>> > >>>> The implementation based on the .interrupt section is not robust. > >>>> Maybe a user linked his firmware correctly in TCML, but the section is not > >>>> called .interrupt so the firmware loading will work. > >>>> > >>>> So, instead of using the section name, you should use the address. > >>> > >>> Can you be more specific on the above? > >>> > >>>> > >>>> First, check whether there is a section linked to TCML. > >>>> If there is none, check for section name - as you did. > >>>> If there is no section called .interrupt, give an error message. > >>> > >>> We have two ways of booting, one that puts the firmware image in the TCML and > >>> another in RAM. Based on the processor type, the first 8 bytes of the TCML need > >>> to include the address for the stack and PC value. > >>> > >>> I think the first thing to do is have two different firmware images, one for > >>> i.MX8M and another one for i.MX93. That should greatly simplify things. > >> > >> sorry, I not got your points. i.MX8M and i.MX93 are not sharing firmware > > > > Perfect. > > > >> images. i.MX93 M33 has ROM, kicking M33 firmware just requires the > >> address of the .interrupt address which holds stack/pc value. > >> i.MX8M not has ROM, kick M33 firmware requires driver to copy > >> stack/pc into the TCML beginning address. > > > > It's been more than a month since I have looked at this patchset so the details are > > vague in my memory. That said, there should be one image for the TCML and > > another one for the RAM. And the image that runs in RAM should have a program > > segment that write the correct information in the first 8 bytes. > > > >> > >> Whether i.MX8M/i.MX93, the NXP released MCU SDK use the section > >> ".interrupt" to hold stack/pc initialization value in the beginning > >> 8 bytes of the section. > >> > > > > And that is fine. Simply release another version of the SDK that does the right > > thing. > > > > I suggest to work with Daniel and Iuliana if some details are still unclear. > > Unlike me, they have access to the reference manual and the boot requirements. > > > > > >>> > >>> Second, there should always be a segment that adds the right information to the > >>> TMCL. That segment doesn't need a name, it simply have to be part of the > >>> segments that are copied to memory (any kind of memory) so that function > >>> rproc_elf_load_segments() can do its job. > >>> > >>> That pushes the complexity to the tool that generates the firmware image, > >>> exactly where it should be. > >> > >> For i.MX8M, yes. For i.MX93, the M33 ROM needs address of storing stack/pc. > >>> > >>> This is how I think we should solve this problem based on the very limited > >>> information provided with this patchset. Please let me know if I missed > >>> something and we'll go from there. > >> > >> I am not sure how to proceed on supporting the current firmware. what should > >> I continue with current patchset? > > I've successfully tested this on i.MX8MM with an elf file generated by > the NXP SDK. > > I would really like to see this upstreamed. If this requires changes > that are not compatible with binaries compiled with the current SDK as > discussed above, that would be fine for me as long as the kernel is able > to detect the malformed binary and warns the user about it. > I agree. > The user can then manually adjust the linker script, etc. in the SDK to > match the requirements of the kernel. > That is exactly what I suggested. > Thanks > Frieder
