diff options
Diffstat (limited to 'board/raspberrypi/rpi')
| -rw-r--r-- | board/raspberrypi/rpi/rpi.env | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/board/raspberrypi/rpi/rpi.env b/board/raspberrypi/rpi/rpi.env new file mode 100644 index 00000000000..30228285edd --- /dev/null +++ b/board/raspberrypi/rpi/rpi.env @@ -0,0 +1,77 @@ +/* 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 |