On 4/8/26 04:30, Peng Fan wrote: >> Subject: Re: [PATCH v2 2/3] remoteproc: imx_rproc: Pass bootaddr to >> SM CPU/LMM reset vector >> > [...] >>> Aligning the ELF entry point with the hardware reset base on >> Cortex‑M >>> systems is possible, but it comes with several risks. >> I'm not asking to align the ELF entry point with the hardware reset base. >> All I want is to have the correct start address embedded in the ELF file >> to avoid having to use a mask. > I see, per my understanding: > FreeRTOS typically exposes __isr_vector, which corresponds to the hardware > reset / vector table base. > Zephyr (Cortex‑M) exposes _vector_table, which serves the same purpose. > I am not certain about other RTOSes, but the pattern seems consistent: > the vector table base is already available as a named ELF symbol. > > Given that, if the preferred approach is to parse the ELF and explicitly > retrieve the hardware reset base, I can update the implementation accordingly. > If you prefer to parse the elf file to get the hardware reset base, > I could update to use them. > > Options1: Something as below: > 1. Include rproc_elf_find_symbol in remoteproc_elf_loader.c > 2. Use below in imx_rproc.c > ret = rproc_elf_find_symbol(rproc, fw, "__isr_vector", &vector_base); > if (ret) > ret = rproc_elf_find_symbol(rproc, fw, "__vector_table", &vector_base); > > if (!ret) > rproc->bootaddr = vector_base > else > dev_info(dev, "no __isr_vector or __vector_table\n") > > This makes the hardware reset base explicit, avoids masking e_entry. > > Option 2: User‑provided reset symbol via sysfs > As an alternative, we could expose a sysfs attribute, > e.g. reset_symbol, allowing users to specify the symbol name > to be used as the reset base: > > echo __isr_vector > /sys/class/remoteproc/remoteprocX/reset_symbol > > The remoteproc core would then resolve that symbol from > the ELF and set rproc->bootaddr accordingly. > This provides maximum flexibility but does introduce a new user‑visible ABI, > so I see it more as an opt‑in or fallback mechanism. > > Please let me know which approach you prefer, and I will update > this series accordingly in v3..
I would go with option 1) as this and having something like this: #define IMX_RPROC_DEFAULT_RST_VECTOR_NAME "..." later we can expand that with a configurable name via sysfs. This was along my initial proposal where you would determine the reset vector address from the elf file.
