Hi Paresh, On Thu Jun 11, 2026 at 8:14 PM CEST, Paresh Bhagat wrote: > Hi Markus, > > Btw Had a quick look at series > > https://lore.kernel.org/all/20260609-topic-am62a-ioddr-dt-v6-19-v6-0-16afba97f...@baylibre.com/ > > I did not know this problem was for other devices too. > > > On 10/06/26 13:42, Markus Schneider-Pargmann wrote: >> Hi Paresh, >> >> On Tue Jun 9, 2026 at 8:10 PM CEST, Paresh Bhagat wrote: >>> This patch series addresses DM firmware reserved memory fixup for AM62a >>> and AM62d: >>> >>> 1. AM62D is missing OF_SYSTEM_SETUP config, required for FDT fixups to >>> be applied before passing dtb to kernel. >>> >>> 2. DM firmware reserved memory region is insufficient to accommodate the >>> binary. Analysis of the DM firmware binary using objdump reveals that >>> the resource_table section and .stack section occupies memory from >>> 0x9c900000 to 0x9e608000. So increase the reserved region size from >>> 0xf00000 to 0x1f00000 via fdt fixup. Add new configs in Kconfig. >> I am wondering why you chose 0x1f00000 and not 0x1d08000? >> >> Also for am62a the firmware linker file says it is shorter: >> /* DDR for DM R5F code/data [ size 27 MiB + 364 KB ] */ >> DDR : ORIGIN = 0x9CAA5000 LENGTH = 0x1B5B000 >> >> >> https://github.com/TexasInstruments/mcupsdk-core-k3/blob/k3_main/examples/drivers/ipc/ipc_rpmsg_echo_linux/am62px-sk/wkup-r5fss0-0_freertos/ti-arm-clang/linker.cmd#L175 >> >> I am wondering what is correct, the linker file or the objdump you did? > > > Yes apart from the objdump output I noticed a gap between end of > wkup_r5fss0_core0_memory_region and start of secure_ddr. So intention to > fix the bug and use all of the available space. > > >> >>> 3. The existing fdt_fixup_reserved_memory() used a delete/recreate >>> approach which corrupted phandle references to DM node, causing DM >>> initialization failures. Fixed it by updating nodes in-place using >>> fdt_setprop() to preserve original phandles. >> I haven't looked at the code yet, why do you use a fixup instead of >> fixing the devicetree? >> >> Best >> Markus > > > I had a discussion with bryan regarding the device tree fix approach. He > pointed out that firmware and kernel versions can be updated > independently which can lead to unused reserved memory. So bootloaders > should dynamically update the reserved memory based on firmware > requirements before handing off to kernel.
Maybe I am missing something here, but isn't the firmware distributed together with u-boot? u-boot gets the devicetree merged from upstream every major version. So isn't a kernel update independent of u-boot/firmware/devicetree update? Also do updates to the memory regions of your firmware really happen that often? Best Markus
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