| /* SPDX-License-Identifier: GPL-2.0+ */ |
| |
| /* environment for Raspberry Pi boards */ |
| |
| dhcpuboot=usb start; dhcp u-boot.uimg; bootm |
| |
| /* Environment */ |
| stdin=serial,usbkbd |
| stdout=serial,vidconsole |
| stderr=serial,vidconsole |
| |
| /* DFU over USB/UDC */ |
| #ifdef CONFIG_CMD_DFU |
| dfu_alt_info=u-boot.bin fat 0 1;uboot.env fat 0 1; |
| config.txt fat 0 1; |
| #ifdef CONFIG_ARM64 |
| dfu_alt_info+=Image fat 0 1 |
| #else |
| dfu_alt_info+=zImage fat 0 1 |
| #endif |
| #endif /* CONFIG_CMD_DFU */ |
| |
| /* |
| * Memory layout for where various images get loaded by boot scripts: |
| * |
| * I suspect address 0 is used as the SMP pen on the RPi2, so avoid this. |
| * |
| * Older versions of the boot firmware place the firmware-loaded DTB at 0x100, |
| * newer versions place it in high memory. So prevent U-Boot from doing its own |
| * DTB + initrd relocation so that we won't accidentally relocate the initrd |
| * over the firmware-loaded DTB and generally try to lay out things starting |
| * from the bottom of RAM. |
| * |
| * kernel_addr_r has different constraints on ARM and Aarch64. For 32-bit ARM, |
| * it must be within the first 128M of RAM in order for the kernel's |
| * CONFIG_AUTO_ZRELADDR option to work. The kernel itself will be decompressed |
| * to 0x8000 but the decompressor clobbers 0x4000-0x8000 as well. The |
| * decompressor also likes to relocate itself to right past the end of the |
| * decompressed kernel, so in total the sum of the compressed and |
| * decompressed kernel needs to be reserved. |
| * |
| * For Aarch64, the kernel image is uncompressed and must be loaded at |
| * text_offset bytes (specified in the header of the Image) into a 2MB |
| * boundary. The 'booti' command relocates the image if necessary. Linux uses |
| * a default text_offset of 0x80000. In summary, loading at 0x80000 |
| * satisfies all these constraints and reserving memory up to 0x02400000 |
| * permits fairly large (roughly 36M) kernels. |
| * |
| * scriptaddr and pxefile_addr_r can be pretty much anywhere that doesn't |
| * conflict with something else. Reserving 1M for each of them at |
| * 0x02400000-0x02500000 and 0x02500000-0x02600000 should be plenty. |
| * |
| * On ARM, both the DTB and any possible initrd must be loaded such that they |
| * fit inside the lowmem mapping in Linux. In practice, this usually means not |
| * more than ~700M away from the start of the kernel image but this number can |
| * be larger OR smaller depending on e.g. the 'vmalloc=xxxM' command line |
| * parameter given to the kernel. So reserving memory from low to high |
| * satisfies this constraint again. Reserving 1M at 0x02600000-0x02700000 for |
| * the DTB leaves rest of the free RAM to the initrd starting at 0x02700000. |
| * Even with the smallest possible CPU-GPU memory split of the CPU getting |
| * only 64M, the remaining 25M starting at 0x02700000 should allow quite |
| * large initrds before they start colliding with U-Boot. |
| */ |
| #ifdef CONFIG_ARM64 |
| fdt_high=ffffffffffffffff |
| initrd_high=ffffffffffffffff |
| #else |
| fdt_high=ffffffff |
| initrd_high=ffffffff |
| #endif |
| kernel_addr_r=0x00080000 |
| scriptaddr=0x02400000 |
| pxefile_addr_r=0x02500000 |
| fdt_addr_r=0x02600000 |
| ramdisk_addr_r=0x02700000 |
| |
| boot_targets=mmc usb pxe dhcp |
