reserved memory of imx7ulkevk

[kayiyeh]

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. 

Regards,

kayiyeh

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

[igorpadykov]

Hi Ka-Yi

one can try using dts "reserved-memory" :

imx7ulp.dtsi\dts\boot\arm\arch - linux-imx - i.MX Linux kernel 

Best regards
igor
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[kayiyeh]

Hi, Igor,

I tried your suggestion with my colleague, but it fail to boot. The boot boot log is as below, and basically, the boot up procedure stop after kernel was loaded to memory and no more message presented and the system is dead.

"

U-Boot 2018.03-imx_v2018.03_4.14.98_2.0.0_ga+g87a19df (May 28 2019 - 19:34:19 +0000)

CPU: Freescale i.MX7ULP rev2.1 at 500 MHz
Reset cause: POR
Boot mode: Dual boot
Model: NXP i.MX7ULP EVK
DRAM: 1 GiB
MMC: FSL_SDHC: 0
Loading Environment from MMC... *** Warning - bad CRC, using default environment

Failed (-5)
No panel detected: default to RM68200_WXGA
Display: RM68200_WXGA (720x1280)
Video: 720x1280x24
In: serial
Out: serial
Err: serial
switch to partitions #0, OK
mmc0 is current device
flash target is MMC:0
Net: Net Initialization Skipped
No ethernet found.
Fastboot: Normal
Normal Boot
Hit any key to stop autoboot: 0
switch to partitions #0, OK
mmc0 is current device
** Unable to read file boot.scr **
7267608 bytes read in 363 ms (19.1 MiB/s)
Booting from mmc ...
21577 bytes read in 16 ms (1.3 MiB/s)
263432 bytes read in 28 ms (9 MiB/s)
## Booting kernel from Legacy Image at 64000000 ...
Image Name:
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 263368 Bytes = 257.2 KiB
Load Address: 64000000
Entry Point: 64000000
Verifying Checksum ... OK
## Flattened Device Tree blob at 63000000
Booting using the fdt blob at 0x63000000
Loading Kernel Image ... OK
Using Device Tree in place at 63000000, end 63008448

Starting kernel ...

E/TC:0 plat_rng_init:354 Warning: seeding RNG with zeroes"

Please help.

[kayiyeh]

Dear Igor,

Thank you for your help.

I already followed the BSP porting guide to git the source code and make the zImage, dts and u-boot.imx. However, I have problem to flash the images to micro SD card.

I follow the BSP porting guide and I can build zImage, *.dts, u-boot.imx. However, I can't figure out how to flash them to my micro SD card. I followed the instruction in the guide to use "dd if=... of=..." but it doesn't work. I searched the web and found there are few people have similar problem as mine but they got few help, too. I want to try the mkimage utility but I don't know what is the correct instruction for a genuine imx7ulpevk board, which I didn't modify anything. Can you help?

Finally, I have to tell you there are at least 2 typos in the I.MX_BSP_Porting_Guide.pdf. And they are not trivial for beginners. In page 10 and 14, the git instruction following a web address mixed "_" with "-" and causing error.

Thank you for you help again.

Regards,

Ka-Yi Yeh