From: Herman Rimm <herman@rimm.ee>
Date: Mon, Sep 16 2024 19:24:02 +0200
Subject: [PATCH] Configure Raspberry Pis to reserve 50 MB for linux kernels.

---
The 6.9 and newer linux-libre-arm64-generic kernels for Guix can be
larger than the allocated 36 MB.  This patch is not submitted upstream.

diff --git a/board/raspberrypi/rpi/rpi.env b/board/raspberrypi/rpi/rpi.env
index 30228285edd..666883e9212 100644
--- a/board/raspberrypi/rpi/rpi.env
+++ b/board/raspberrypi/rpi/rpi.env
@@ -43,22 +43,22 @@ dfu_alt_info+=zImage fat 0 1
  *   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.
+ *   satisfies all these constraints and reserving memory up to 0x03400000
+ *   permits fairly large (roughly 50M) 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.
+ * 0x03200000-0x03300000 and 0x03300000-0x03400000 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.
+ * satisfies this constraint again. Reserving 1M at 0x03400000-0x03500000 for
+ * the DTB leaves rest of the free RAM to the initrd starting at 0x03500000.
  * Even with the smallest possible CPU-GPU memory split of the CPU getting
- * only 64M, the remaining 25M starting at 0x02700000 should allow quite
+ * only 64M, the remaining 11M starting at 0x03500000 should allow quite
  * large initrds before they start colliding with U-Boot.
  */
 #ifdef CONFIG_ARM64
@@ -69,9 +69,9 @@ 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
+scriptaddr=0x03200000
+pxefile_addr_r=0x03300000
+fdt_addr_r=0x03400000
+ramdisk_addr_r=0x03500000
 
 boot_targets=mmc usb pxe dhcp