Hi Alexander, On Thu, 24 May 2018 10:12:54 +0200 Alexander Graf <ag...@suse.de> wrote:
> 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? I believe fdt_addr is what is passed to the kernel and fdt_blob is what U-Boot's device model is using. > So as long as we keep the load addresses low enough, we should be safe. Good. > 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. Makes sense, but I guess needs some documentation. Also for existing things like whether enable_uart=1 is needed or not. > > Alex > > [1] https://github.com/raspberrypi/firmware/issues/943 Thanks, Tuomas _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
