K230 Memory Optimization Guide#
Memory Analysis#
Please refer to the document K230_Memory_Usage_Analysis_Guide.md
Memory Optimization#
Small-core Memory Optimization#
Linux Module Deletion#
Based on the introduction of ksize.py in the memory usage analysis guide, unnecessary modules or configuration information can be deleted, for example:
Remove CONFIG_IKCONFIG/CONFIG_IKCONFIG_PROC: The .config support within the kernel, also known as IKCONFIG, allows system administrators to build a copy of the configuration used during kernel build into the kernel itself. This allows checking the kernel’s configuration while the kernel is running without worrying about changes or cleaning the kernel source directory after compilation.
Remove CONFIG_KPROBES
Remove CONFIG_ACORN_*, Acorn is an application packaging and deployment framework that simplifies running applications on Kubernetes.
Remove CONFIG_SGI_PARTITION
Remove CONFIG_ULTRIX_PARTITION
Remove CONFIG_IPV6
Remove CONFIG_IP_PNP, this option enables the automatic configuration of the device’s IP address and routing table based on information provided on the kernel command line or protocols like BOOTP/DHCP/RARP during kernel startup.
Remove CONFIG_NET_9P, CONFIG_NET_9P is a Linux kernel configuration option for enabling 9P protocol network file system support.
Remove CONFIG_VIRITO_NET, remove virtual network support
Remove unnecessary filesystem drivers, such as removing support for ext2, ext4, nfs, jffs, 9pfs, etc., if using flash ubifs.
Remove CONFIG_FTRACE, remove FTRACE debugging options
Set CONFIG_SECTION_ALIGN_4KB=y to change the segment alignment size of the kernel to 4KB, effectively avoiding excessive memory usage due to segment alignment.
Remove SWIOTLB, this option handles the capability of the DMA controller to access address ranges, which is not needed for K230. It needs to be deleted in arch/riscv/Kconfig with
select SWIOTLB if MMU.
In the current Linux code, you can refer to the following trimmed defconfig files located at k230_sdk/src/little/linux/arch/riscv/configs:
k230_evb_fastboot_defconfig # Regular fastboot configuration file
k230_evb_doorlock_defconfig # Configuration file for door locks, optimized for memory by default
LVGL Display Memory Optimization#
This section mainly introduces how to reduce the display memory usage for LVGL, taking the door lock POC as an example. Refer to the code at src/little/buildroot-ext/package/door_lock/src/ui/.
Use ARGB4444 or RGB565 as referenced in the door lock POC lvgl_port/k230/lv_port_disp.cpp with the following code:
static int disp_init(void)
{
if (drm_dev_setup(&drm_dev, DRM_DEV_NAME_DEFAULT))
return -1;
drm_get_resolution(&drm_dev, &screen_width, &screen_height);
input_map_set(0);
for (int i = DRM_UI_BUF_START_IDX; i < DRM_UI_BUF_END_IDX; i++) {
drm_bufs[i].width = ALIGNED_UP_POWER_OF_TWO(display_width, 3);
drm_bufs[i].height = ALIGNED_DOWN_POWER_OF_TWO(display_height, 0);
drm_bufs[i].offset_x = (screen_width - display_width) / 2;
drm_bufs[i].offset_y = (screen_height - display_height);
drm_bufs[i].fourcc = DRM_FORMAT_ARGB4444;
drm_bufs[i].bpp = 16;
buf_mgt_reader_put(&ui_buf_mgt, (void *)i);
}
}
Reduce the DRM buffer to 2 by modifying the door lock POC lvgl_port/k230/lv_port_disp.cpp with the following code:
#define DRM_UI_BUF_COUNT 2
Large-core Memory Optimization#
Memory Reuse#
In the current K230 heterogeneous system SDK, multimedia tasks are generally placed on the large core. Before the application on the large core is fully started, the ELF application of the large core can be loaded into the MMZ address range via ROMFS. The downside of this method is that the program can only run once, and currently only supports spinor flash boot method.
Use the make menuconfig command in the k230_sdk directory to configure the SDK’s memory distribution range. After entering the command, choose Memory configuration--->spi nor cfg part configuration to configure.
Refer to the door lock POC configuration file k230_sdk/configs/k230_evb_doorlock_defconfig.
CONFIG_MEM_MMZ_BASE=0x5c00000
CONFIG_MEM_MMZ_SIZE=0x2000000
CONFIG_MEM_RTAPP_BASE=0x5c00000 # Reuse MMZ address space
CONFIG_MEM_RTAPP_SIZE=0x2000000
Multimedia Memory Optimization#
To meet the program’s needs, minimize the number of VBs. After the program starts, use the msh command to input cat /proc/umap/vb to check the VB usage information. The maximum optimization limit of the VB quantity can be judged by the MinFree attribute of each pool.
-----VB PUB CONFIG--------------------------------------------------------------
MaxPoolCnt
10
-----VB SUPPLEMENT ATTR---------------------------------------------------------
Config Size VbCnt
1 204 21
-----COMMON POOL CONFIG---------------------------------------------------------
PoolConfId BlkSize Count RemapMode
0 8294400 5 CACHED
1 8192 3 NONE
2 4096 5 NOCACHE
-----MODULE COMMON MOD POOL CONFIG of [2]---------------------------------------
PoolConfId BlkSize Count RemapMode
0 4096 5 CACHED
1 8192 3 NONE
-------------------------------------------------------------------------------------
PoolId PhysAddr VirtAddr IsComm Owner BlkSz BlkCnt Free MinFree
0 0x18001000 0xc00d1000 1 -1 8294400 5 2 2
BLK VI VENC VDEC VO USER AI AREC AENC ADEC AO V_VI V_VO DMA DPU
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0
1 0 0 0 0 1 0 0 0 0 0 0 0 0 0
2 0 0 0 0 1 0 0 0 0 0 0 0 0 0
Sum 0 0 0 0 3 0 0 0 0 0 0 0 0 0
-------------------------------------------------------------------------------------
PoolId PhysAddr VirtAddr IsComm Owner BlkSz BlkCnt Free MinFree
1 0x1a78f000 0x0 1 -1 8192 3 3 3
-------------------------------------------------------------------------------------
PoolId PhysAddr VirtAddr IsComm Owner BlkSz BlkCnt Free MinFree
2 0x1a796000 0xc2860000 1 -1 4096 5 5 5
-------------------------------------------------------------------------------------
PoolId PhysAddr VirtAddr IsComm Owner BlkSz BlkCnt Free MinFree
3 0x1a79c000 0xc2866000 1 2 4096 5 5 5
-------------------------------------------------------------------------------------
PoolId PhysAddr VirtAddr IsComm Owner BlkSz BlkCnt Free MinFree
4 0x1a7a2000 0x0 1 2 8192 3 3 3
ISP Memory Usage Optimization#
Enable the dynamic memory allocation function of MCM. When configuring VICAP with kd_mpi_vicap_set_dev_attr, set dev_attr.pipe_ctrl.bits.dnr3_enable to 0.
RT-Smart System Memory Optimization#
Heap Memory Optimization#
Use the free and list_page commands in the msh command line to get the maximum usage of the entire system heap memory and page memory. Adjust the heap memory and page memory size based on the maximum value obtained. In tools/menuconfig_to_code.sh, when compiling the CONFIG options of the door lock POC, the heap memory size of RT-Smart is configured to 4M.
if [ "${CONFIG_BOARD_NAME}" = "k230_evb_doorlock" ]; then RT_HW_HEAP_END_SIZE="0x400000"; fi;
Page Memory Optimization#
Based on the optimized heap memory size, the static size of the RT-Smart image itself, and the maximum value obtained from the list_page command, you can determine the overall memory size required by the RT-Smart system. This size can be configured by entering make menuconfig in the k230_sdk directory.
Memory Optimization Results#
After the above configuration optimizations, the K230 door lock POC program only needs 128M of physical memory to run. The memory usage of each module in the door lock POC can be referenced in the configuration file k230_sdk/configs/k230_evb_doorlock_defconfig.
CONFIG_MEM_TOTAL_SIZE=0x8000000 # Total memory usage is 128M
CONFIG_MEM_QUICK_BOOT_CFG_BASE=0x00000000 # Uboot fastboot parameter memory range
CONFIG_MEM_QUICK_BOOT_CFG_SIZE=0x00040000
CONFIG_MEM_SENSOR_CFG_BASE=0x00040000 # Sensor configuration parameter memory range
CONFIG_MEM_SENSOR_CFG_SIZE=0x000c0000
CONFIG_MEM_IPCM_BASE=0x00100000 # Inter-core communication memory range
CONFIG_MEM_IPCM_SIZE=0x00100000
CONFIG_MEM_RTT_SYS_BASE=0x0200000 # Memory range used by the large core RT-Smart
CONFIG_MEM_RTT_SYS_SIZE=0x02000000
CONFIG_MEM_LINUX_SYS_BASE=0x2200000 # Memory range used by the small core Linux
CONFIG_MEM_LINUX_SYS_SIZE=0x3a00000
CONFIG_MEM_AI_MODEL_BASE=0x7d00000 # Memory range used by AI models
CONFIG_MEM_AI_MODEL_SIZE=0x0200000
CONFIG_MEM_FACE_DATA_BASE=0x7c00000 # Memory range used by facial data
CONFIG_MEM_FACE_DATA_SIZE=0x040000
CONFIG_MEM_SPECKLE_BASE=0x7c40000 # Memory range used by speckle data, only for OV9286
CONFIG_MEM_SPECKLE_SIZE=0x10000
CONFIG_MEM_MMZ_BASE=0x5c00000 # Multimedia memory range
CONFIG_MEM_MMZ_SIZE=0x2000000
CONFIG_MEM_RTAPP_BASE=0x5c00000 # Memory range occupied by RT-Smart applications in ROMFS
CONFIG_MEM_RTAPP_SIZE=0x2000000