board: qualcomm: dragonboard820c: update readme
Update build instructions.
Be sure to use the u-boot-nodtb.bin image, as the Snapdragon platform
prioritizes the embedded Device Tree Blob (DTB) when present, rather
than the external one. The external DTB—modified by LK—is the version
required by the DB820c.
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez@oss.qualcomm.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Christopher Obbard <christopher.obbard@linaro.org>
Reviewed-by:
Link: https://lore.kernel.org/r/20250407175617.3494506-1-jorge.ramirez@oss.qualcomm.com
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
diff --git a/board/qualcomm/dragonboard820c/readme.txt b/board/qualcomm/dragonboard820c/readme.txt
index 966e952..a01d241 100644
--- a/board/qualcomm/dragonboard820c/readme.txt
+++ b/board/qualcomm/dragonboard820c/readme.txt
@@ -16,10 +16,7 @@
Build & Run instructions
================================================================================
-1) Install mkbootimg and dtbTool from Codeaurora:
-
- git://codeaurora.org/quic/kernel/skales
- commit 8492547e404e969262d9070dee9bdd15668bb70f worked for me.
+1) Install mkbootimg
2) Setup CROSS_COMPILE to aarch64 compiler or if you use ccache just do
CROSS_COMPILE="ccache aarch64-linux-gnu-"
@@ -33,15 +30,15 @@
$ touch rd
-5) Generate qualcomm device tree table with dtbTool
+5) Append the dtb to the u-boot binary discarding the internal dtb.
- $ dtbTool -o dt.img arch/arm/dts
+ $ gzip u-boot-nodtb.bin
+ $ cat u-boot.dtb >> u-boot-nodtb.bin.gz
6) Generate Android boot image with mkbootimg:
- $ mkbootimg --kernel=u-boot-dtb.bin \
+ $ mkbootimg --kernel=u-boot-nodtb.bin.gz \
--output=u-boot.img \
- --dt=dt.img \
--pagesize 4096 \
--base 0x80000000 \
--ramdisk=rd \
@@ -251,44 +248,42 @@
[5300] booting linux @ 0x80080000, ramdisk @ 0x82200000 (0), tags/device tree @ 0x82000000
[5310] Jumping to kernel via monitor
-U-Boot 2017.11-00145-ge895117 (Nov 29 2017 - 10:04:06 +0100)
+U-Boot 2025.04-rc5-00020-g40a61ca0e7eb-dirty (Apr 07 2025 - 09:37:03 +0200)
Qualcomm-DragonBoard 820C
-DRAM: 3 GiB
-PSCI: v1.0
-MMC: sdhci@74a4900: 0
+DRAM: 3.5 GiB (effective 3 GiB)
+Core: 136 devices, 18 uclasses, devicetree: board
+MMC: Bulk clocks not available (-19), trying core clock
+mmc@74a4900: 0
+Loading Environment from EXT4... OK
In: serial@75b0000
Out: serial@75b0000
Err: serial@75b0000
-Net: Net Initialization Skipped
-No ethernet found.
+Net: No ethernet found.
Hit any key to stop autoboot: 0
switch to partitions #0, OK
mmc0 is current device
Scanning mmc 0:1...
Found /extlinux/extlinux.conf
Retrieving file: /extlinux/extlinux.conf
-433 bytes read in 71 ms (5.9 KiB/s)
1: nfs root
-
+Enter choice: 1: nfs root
Retrieving file: /uImage
-19397184 bytes read in 2024 ms (9.1 MiB/s)
-append: root=/dev/nfs rw nfsroot=192.168.1.2:/db820c/rootfs,v3,tcp rootwait ip=dhcp consoleblank=0 console=tty0 console=ttyMSM0,115200n8 earlyprintk earlycon=msm_serial_dm,0x75b0000 androidboot.bootdevice=624000.ufshc androidboot.verifiedbootstate=orange androidboot.ver0
-
+append: root=/dev/nfs rw nfsroot=192.168.1.6:/home/jramirez/Src/qualcomm-lt/db820c/rootfs,v3,tcp rootwait ip=dhcp consoleblank=0 console=tty0 console=ttyMSM0,115200n8 earlyprintk earlyco0
Retrieving file: /apq8096-db820c.dtb
-38134 bytes read in 37 ms (1005.9 KiB/s)
-
-## Booting kernel from Legacy Image at 95000000 ...
+## Booting kernel from Legacy Image at 155000000 ...
Image Name: Dragonboard820c
Image Type: AArch64 Linux Kernel Image (uncompressed)
Data Size: 19397120 Bytes = 18.5 MiB
Load Address: 80080000
Entry Point: 80080000
Verifying Checksum ... OK
-## Flattened Device Tree blob at 93000000
- Booting using the fdt blob at 0x93000000
- Loading Kernel Image ... OK
- Using Device Tree in place at 0000000093000000, end 000000009300c4f5
+## Flattened Device Tree blob at 148600000
+ Booting using the fdt blob at 0x148600000
+Working FDT set to 148600000
+ Loading Kernel Image to 80080000
+ Using Device Tree in place at 0000000148600000, end 000000014860c4f5
+Working FDT set to 148600000
Starting kernel ...