Jetson TK1 4GB DRAM upgrade

Hardware

Jetson TK1 ships with four H5TC4G63AFR-RDA 256Mb x 16 DDR3L ICs. These can be replaced with 512Mb x 16 DDR3L ICs for a total capacity of 4GB. The replacements I've used are H5TC8G63AMR-PBA.

Requirements:

• BGA rework capabilities - outside the scope of this document
• 8Gb replacement ICs - these are quite difficult to find, I got mine on Aliexpress (listing no longer available)
• replacement thermal paste because the heatsink must be removed while reworking the board
• a host computer with the Jetson driver package for setting up the Jetson board
• the L4T kernel source

I recommend replacing one IC at a time and testing that everything works correctly in between. This makes it possible to catch any soldering issues. A mix of H5TC4G63AFR and H5TC8G63AMR seems to work correctly with the default SDRAM configuration, but only 2 GB of memory are available.

Software configuration

The default kernel configuration doesn't allow use of more than 2GB of RAM. The following options must be enabled:

• System Type > Full 4GB physical memory support
• System Type > Support for the Large Physical Address Extension

A patch is required to limit the range of memory used for DMA buffers to the first 4GB of physical memory.

The default vmalloc size might need to be increased, either by passing a kernel argument (e.g. vmalloc=300M) or by applying another patch to increase the default size.

The updated kernel image can be flashed by replacing Linux_for_Tegra/kernel/zImage and running:

sudo ./flash.sh -k 6 jetson-tk1 mmcblk0p1

Finally, access to the full 4GB of RAM is enabled by writing a new BCT file with the updated SDRAM configuration:

sudo nvflash --bct PM375_Hynix_4GB_H5TC8G63AMR_PBA_792MHz.cfg --updatebct SDRAM --bl ./fastboot.bin --go

This configuration was derived from the E1780_Hynix_4GB_H5TC8G63AMR_PBA_792Mhz.cfg and PM375_Hynix_2GB_H5TC4G63AFR_RDA_792MHz.cfg files provided by NVIDIA. This configuration works for me, but it might not be stable on other units.

The bootloader should then automatically pass similar parameters to the kernel:

mem=1862M@2048M mem=2048M@4096M ddr_die=2048M@2048M ddr_die=2048M@4096M

License

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