U-Boot fails to load a large ramdisk into memory properly (tested to occur with a 20MB image on the zynq microzed). I have found a solution to the problem but I'm unsure how to fix the problem in buildroot.


The U-Boot environment variable 'sdboot' is set to 

echo Booting from SD...; run envload; run fpgaboot; fatload mmc 0 0x1000000 ${kernel_image} && fatload mmc 0 0x2000000 ${ramdisk_image} && fatload mmc 0 0x3000000 ${devicetree_image} && bootm 0x1000000 0x2000000 0x3000000

I believe the device tree is being written on top of the ramdisk. The system boots when 'sdboot' is set to 

echo Booting from SD...; run envload; run fpgaboot; fatload mmc 0 0x1000000 ${kernel_image} && fatload mmc 0 0x3000000 ${ramdisk_image} && fatload mmc 0 0x2000000 ${devicetree_image} && bootm 0x1000000 0x3000000 0x2000000

Here is a log of the default boot behavior.

######## begin boot log ########
U-Boot 2015.07 (Jul 07 2016 - 05:52:07 -0400)

Model: Zynq MicroZED Board
I2C: ready
DRAM: ECC disabled 1 GiB
MMC: zynq_sdhci: 0
Using default environment

In: serial
Out: serial
Err: serial
Model: Zynq MicroZED Board
Net: Gem.e000b000
Error: Gem.e000b000 address not set.

Hit any key to stop autoboot: 0
Booting from SD...
Device: zynq_sdhci
Manufacturer ID: 2
OEM: 544d
Name: SA04G
Tran Speed: 50000000
Rd Block Len: 512
SD version 3.0
High Capacity: Yes
Capacity: 3.6 GiB
Bus Width: 4-bit
Erase Group Size: 512 Bytes
reading uEnv.txt
** Unable to read file uEnv.txt **
reading system.bit
** Unable to read file system.bit **
FPGA image system.bit was not found, skipping...
reading uImage
3450752 bytes read in 309 ms (10.6 MiB/s)
reading rootfs.cpio.uboot
23719921 bytes read in 2027 ms (11.2 MiB/s)
reading zynq-zed.dtb
9141 bytes read in 19 ms (469.7 KiB/s)
## Booting kernel from Legacy Image at 01000000 ...
Image Name: Linux-3.18.0-xilinx
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 3450688 Bytes = 3.3 MiB
Load Address: 00008000
Entry Point: 00008000
Verifying Checksum ... OK
## Loading init Ramdisk from Legacy Image at 02000000 ...
Image Name:
Image Type: ARM Linux RAMDisk Image (uncompressed)
Data Size: 23719857 Bytes = 22.6 MiB
Load Address: 00000000
Entry Point: 00000000
Verifying Checksum ... Bad Data CRC
Ramdisk image is corrupt or invalid
zynq-uboot>
######## end boot log ########