how to update vmalloc space in SDK 1.7

tbowen — Thu, 22 Jan 2015 21:19:04 GMT

Background:

We have recently upgraded our board (similar to the P2020RDB) to use a 256MB NOR flash, up from 64MB NOR. During boot, the kernel complains about not being able to vmalloc enough space to cover the increased 256MB NOR:

Memory: 2005736K/2097152K available (5828K kernel code, 304K rwdata, 1604K rodata, 248K init, 183K bss, 91416K reserved, 1310716K highmem)

Kernel virtual memory layout:

* 0xfffbf000..0xfffff000 : fixmap

* 0xff800000..0xffc00000 : highmem PTEs

* 0xff7fc000..0xff800000 : early ioremap

* 0xf1000000..0xff7fc000 : vmalloc & ioremap

...

vmap allocation for size 268439552 failed: use vmalloc=<size> to increase size.

of-flash e0000000.nor: Failed to ioremap() flash region

of-flash: probe of e0000000.nor failed with error -12

Based on this forum thread:

How can I get more vmalloc/ioremap space?

We previously (LTIB-era) shifted the page_offset / task_size boundary to allow for more kernel and vmalloc space with the following kernel-config subsection:

# Advanced setup

CONFIG_ADVANCED_OPTIONS=y

CONFIG_LOWMEM_SIZE_BOOL=y

CONFIG_LOWMEM_SIZE=0x30000000

# CONFIG_LOWMEM_CAM_NUM_BOOL is not set

CONFIG_LOWMEM_CAM_NUM=3

# CONFIG_RELOCATABLE is not set

CONFIG_PAGE_OFFSET_BOOL=y

CONFIG_PAGE_OFFSET=0xa0000000

CONFIG_KERNEL_START_BOOL=y

CONFIG_KERNEL_START=0xa0000000

# CONFIG_PHYSICAL_START_BOOL is not set

CONFIG_PHYSICAL_START=0x00000000

CONFIG_PHYSICAL_ALIGN=0x04000000

CONFIG_TASK_SIZE_BOOL=y

CONFIG_TASK_SIZE=0xa0000000

CONFIG_NET=y

We recently updated to the latest SDK 1.7, which also exhibits the same VMALLOC era. So, after a full Yocto/SDK-1.7 build for the P2020RDB, I have tried to modify the kernel config with the above options by following these directions:

Linux Kernel

Which are in short:

$ cd <SDK-V1.7>/poky/build_p2020rdb_release

$ bitbake -c menuconfig virtual/kernel

<... make above changes via Advanced menu ...>

$ bitbake -c compile -f virtual/kernel

$ bitbake virtual/kernel

$ cp -L tmp/deploy/images/p2020rdb/uImage <TFTP server path to test new kernel>

Problem:

Here's the problem: Many of my changes persist and are included in the new kernel. However, several changes - SquashFS, disabling unused file-systems, enable timestamp in printk and most importantly adding the above advanced options - are lost! If I run menuconfig again, I see that they are missing. ... It appears that specific kernel config options - not all - are overwritten as part of each build.

How do I stop this behavior and force my changes to be included in the new kernel?

Thanks!

Trevor

Re: how to update vmalloc space in SDK 1.7

tbowen — Thu, 22 Jan 2015 22:13:45 GMT

Found the problem ... I have to manually perform a "Save" to ".config" during menuconfig. I'm not accustomed to that extra step. Also, I'm not sure why part of my config changes are saved ...

topic how to update vmalloc space in SDK 1.7 in P-Series

how to update vmalloc space in SDK 1.7

Background:

Problem:

Re: how to update vmalloc space in SDK 1.7