- * ramdisk_addr_r simply shouldn't overlap anything else. Choosing 33M allows
- * for any boot script to be up to 1M, which is hopefully 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.