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reserved memory of imx7ulkevk

Question asked by Ka-Yi Yeh on Mar 28, 2019
Latest reply on Jun 3, 2019 by Ka-Yi Yeh

Hi, there,

I build an core-image-minimal image for my imx7ulpevk board with 4.14 kernel. And I found after boot up, the kernel occupies about 120MB, which is about 50% more than that of imx8evk build:


"imx7ulpevk login: root
root@imx7ulpevk:~# free -m
                  total          used       free          shared       buffers       cached
Mem:         991212    120944    870268    8496          1860          35932
-/+ buffers/cache: 83152 908060
Swap: 0 0 0"


I checked the boot log and found it may caused by the reserved memory:


"Reserved memory: created CMA memory pool at 0x92000000, size 192 MiB
OF: reserved mem: initialized node linux,cma, compatible id shared-dma-pool
DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map"


I tried to use menuconfig to turn off the CMA, but it doesn't help because the total memory the system can use is reduced to 800MB:


"root@imx7ulpevk:~# free -m
                     total          used             free             shared       buffers    cached
Mem:            794988      120728        674260       8536          2088       35516
-/+ buffers/cache: 83124 711864
Swap: 0 0 0"


Is there any method to keep the total memory as 1GB and remove the reserved memory as least as possible? Because all I need is to run a memory test program and I don't need any peripheral except MMC to boot up, not even panel display. 




p.s the attached files are the log files for the two cases, wish it may help.