From 983dc939ab652b3fc61837d0c228c663c31d6def Mon Sep 17 00:00:00 2001
From: Rodrigo Arias Mallo <rodrigo.arias@bsc.es>
Date: Fri, 12 Jul 2024 14:43:09 +0200
Subject: [PATCH] Move the FDT to 0x80100000

---
 JOURNAL.md     | 118 +++++++++++++++++++++++++++++++++++++++++++++++++
 lagarto-ox.nix |   4 ++
 2 files changed, 122 insertions(+)

diff --git a/JOURNAL.md b/JOURNAL.md
index f53252c..642d562 100644
--- a/JOURNAL.md
+++ b/JOURNAL.md
@@ -1752,3 +1752,121 @@ clears the -3 error.
 I'll leave it at 0x40002000, but I suspect the address might be 0x40170000:
 
     #define OX_ALVEO_TIMER_BASE		0x40170000
+
+After booting again, now it seems to work. But I'm not sure if that
+may cause more problems down the line.
+
+    GGGGGGGGG
+    OpenSBI v1.5
+       ____                    _____ ____ _____
+      / __ \                  / ____|  _ \_   _|
+     | |  | |_ __   ___ _ __ | (___ | |_) || |
+     | |  | | '_ \ / _ \ '_ \ \___ \|  _ < | |
+     | |__| | |_) |  __/ | | |____) | |_) || |_
+      \____/| .__/ \___|_| |_|_____/|____/_____|
+            | |
+            |_|
+
+    sbi_timer_init: begins
+    sbi_timer_init: got Zicntr extension
+    fdt_timer_cold_init: pos = 0
+    fdt_timer_cold_init: got match, name = riscv,aclint-mtimer
+    fdt_timer_cold_init: enabled
+    timer_mtimer_cold_init: begins, is_clint = 0
+    timer_mtimer_cold_init: mtime_addr = 0x40002000
+    timer_mtimer_cold_init: mtime_size = 0x00000008
+    timer_mtimer_cold_init: mtimecmp_addr = 0x40002008
+    timer_mtimer_cold_init: mtimecmp_size = 0x00000008
+    fdt_timer_cold_init: drc->cold_init = 0
+    fdt_timer_cold_init: pos = 1
+    fdt_timer_cold_init: returns 0
+    Platform Name             : Barcelona Supercomputing Center - Lagarto Ox (NixOS)
+    Platform Features         : medeleg
+    Platform HART Count       : 1
+    Platform IPI Device       : ---
+    Platform Timer Device     : aclint-mtimer @ 50000Hz
+    Platform Console Device   : uart8250
+    Platform HSM Device       : ---
+    Platform PMU Device       : ---
+    Platform Reboot Device    : ---
+    Platform Shutdown Device  : ---
+    Platform Suspend Device   : ---
+    Platform CPPC Device      : ---
+    Firmware Base             : 0x80000000
+    Firmware Size             : 327 KB
+    Firmware RW Offset        : 0x40000
+    Firmware RW Size          : 71 KB
+    Firmware Heap Offset      : 0x49000
+    Firmware Heap Size        : 35 KB (total), 2 KB (reserved), 11 KB (used), 21 KB (free)
+    Firmware Scratch Size     : 4096 B (total), 408 B (used), 3688 B (free)
+    Runtime SBI Version       : 2.0
+
+    Domain0 Name              : root
+    Domain0 Boot HART         : 0
+    Domain0 HARTs             : 0*
+    Domain0 Region00          : 0x0000000040002000-0x000000004000200f M: (I,R,W) S/U: ()
+    Domain0 Region01          : 0x0000000040001000-0x0000000040001fff M: (I,R,W) S/U: (R,W)
+    Domain0 Region02          : 0x0000000080040000-0x000000008005ffff M: (R,W) S/U: ()
+    Domain0 Region03          : 0x0000000080000000-0x000000008003ffff M: (R,X) S/U: ()
+    Domain0 Region04          : 0x0000000040800000-0x0000000040bfffff M: (I,R,W) S/U: (R,W)
+    Domain0 Region05          : 0x0000000000000000-0xffffffffffffffff M: () S/U: (R,W,X)
+    Domain0 Next Address      : 0x0000000080200000
+    Domain0 Next Arg1         : 0x0000000082200000
+    Domain0 Next Mode         : S-mode
+    Domain0 SysReset          : yes
+    Domain0 SysSuspend        : yes
+
+    Boot HART ID              : 0
+    Boot HART Domain          : root
+    Boot HART Priv Version    : v1.10
+    Boot HART Base ISA        : rv64imafdc
+    Boot HART ISA Extensions  : zicntr,zihpm,sdtrig
+    Boot HART PMP Count       : 0
+    Boot HART PMP Granularity : 0 bits
+    Boot HART PMP Address Bits: 0
+    Boot HART MHPM Info       : 29 (0xfffffff8)
+    Boot HART Debug Triggers  : 0 triggers
+    Boot HART MIDELEG         : 0x0000000000000222
+    Boot HART MEDELEG         : 0x000000000000b109
+
+    <debug_uart>
+    Core:  12 devices, 8 uclasses, devicetree: board
+    Loading Environment from nowhere... OK
+    In:    serial,usbkbd
+    Out:   serial,vidconsole
+    Err:   serial,vidconsole
+    No working controllers found
+    Net:   No ethernet found.
+    Working FDT set to 82200000
+    Hit any key to stop autoboot:  0
+
+    Device 0: unknown device
+
+    Device 1: unknown device
+    scanning bus for devices...
+
+    Device 0: unknown device
+    starting USB...
+    No working controllers found
+    No ethernet found.
+    No ethernet found.
+
+However, now I cannot boot the kernel, as it is overwritting the FDT:
+
+    => printenv fdtcontroladdr
+    fdtcontroladdr=82200000
+    => fdt addr ${fdtcontroladdr }
+    Working fdt: 82200000
+    => setenv bootargs "root=/dev/ram0 loglevel=7 debug rw earlycon=sbi console=hvc0"
+    => setenv ramdisk_size 12614846
+    => #booti ${kernel_addr_r} ${ramdisk_addr_r}:${ramdisk_size} ${fdtcontroladdr}
+    => printenv kernel_addr_r
+    kernel_addr_r=0x84000000
+    => printenv ramdisk_addr_r
+    ramdisk_addr_r=0x8c300000
+    => booti ${kernel_addr_r} ${ramdisk_addr_r}:${ramdisk_size} ${fdtcontroladdr}
+    Moving Image from 0x84000000 to 0x80200000, end=83044650
+    ERROR: Did not find a cmdline Flattened Device Tree
+    Could not find a valid device tree
+
+Let's move the FDT to 0x80100000.
diff --git a/lagarto-ox.nix b/lagarto-ox.nix
index c9ab49c..2cecee9 100644
--- a/lagarto-ox.nix
+++ b/lagarto-ox.nix
@@ -317,6 +317,10 @@
         #"PLATFORM_RISCV_ABI=lp64d"
         "FW_PAYLOAD_PATH=${final.uboot}/u-boot-nodtb.bin"
         "FW_FDT_PATH=${final.ox-dtb}"
+
+        # Ensure it doesn't overlap from the 0x80200000 where the kernel will be
+        # placed.
+        "FW_PAYLOAD_FDT_ADDR=0x80100000"
       ];
       patches = [
         ./opensbi-timer-debug.patch