/* 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