On 14.04.18 20:04, Tuomas Tynkkynen wrote: > Hi Alexander, > > On Fri, 13 Apr 2018 17:49:00 +0200 > Alexander Graf <ag...@suse.de> wrote: > > [...] >> >> diff --git a/include/configs/rpi.h b/include/configs/rpi.h >> index 325e52a019..fcf7e0976b 100644 >> --- a/include/configs/rpi.h >> +++ b/include/configs/rpi.h >> @@ -124,7 +124,7 @@ >> #define ENV_MEM_LAYOUT_SETTINGS \ >> "fdt_high=ffffffff\0" \ >> "initrd_high=ffffffff\0" \ >> - "fdt_addr_r=0x00000100\0" \ >> + "fdt_addr_r=0x01f00000\0" \ >> "pxefile_addr_r=0x00100000\0" \ >> "kernel_addr_r=0x01000000\0" \ >> "scriptaddr=0x02000000\0" \ > > Note that above the #define is a larger comment block that needs to be > updated as well. Also the other addresses also need updatingfor bigger > kernels on AArch64: https://patchwork.ozlabs.org/patch/777725/ > > Though now I double-checked that the smallest possible GPU-CPU memory > split is actually 64MB for the CPU, not 128M. So maybe something like: > > "kernel_addr_r=0x00080000\0" \ > "fdt_addr_r=0x02400000\0" \ > "scriptaddr=0x02500000\0" \ > "pxefile_addr_r=0x02600000\0" \ > "ramdisk_addr_r=0x02700000\0" > > which would allow a kernel up to 36M, 1M for dtb, script and pxe files > each, and at least 25M for the initrd. Also I think giving up with the > constraint of locating the zImage high enough so that the kernel > decompressor doesn't need to relocate itself can be dropped. If the > boot speed of their Raspi matters that much, probably they wouldn't use > U-Boot in the first place. > > What is the address that the RPi firmware loads its device tree to? I > hope that we don't have to worry about the positioning of that too...
U-Boot> bdinfo arch_number = 0x00000000 boot_params = 0x00000100 DRAM bank = 0x00000000 -> start = 0x00000000 -> size = 0x3B400000 baudrate = 115200 bps TLB addr = 0x3B3F0000 relocaddr = 0x3B348000 reloc off = 0x3B2C8000 irq_sp = 0x3AF3E120 sp start = 0x3AF3E120 Early malloc usage: 138 / 2000 fdt_blob = 000000003af3e130 U-Boot> print fdt_addr fdt_addr=2effb300 So on boot the DT passed into U-Boot is either at ~750MB or close to the top. I can't quite find any code that explains the difference in the two variables. Either way, I guess firmware tries to put it reasonably high? So as long as we keep the load addresses low enough, we should be safe. Also fyi, I would like to switch to CONFIG_OF_BOARD by default, once I added code that marks u-boot.bin as an "upstream kernel" for the RPi firmware, because then newer RPi firmwares will pass us a fully upstream compatible device tree [1] which we can then pass on to Linux as default. Alex [1] https://github.com/raspberrypi/firmware/issues/943 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
