Hello,
I’m trying to run **LVGL 9.3** on a **nRF52840 DK** with a **2.8" ILI9341 TFT display (SPI)** using **NCS v3.1.0 / Zephyr 4.1 / Toolchain v3.1.0**.
### Problem
The app compiles and starts, but I get some **malloc fails**.
The fault seems related to mallocs inside LVGL during initialization.
The crash happens later.
First `lv_label_create` returns a null pointer, then I call `lv_label_set_text()` and it crashes in `main()`. But the root seems to be in `lv_image_decoder_init()`.
### Error location
File:
```
C:\ncs\v3.1.0\modules\lib\gui\lvgl\src\draw\lv_image_decoder.c:65
```
Function where the first malloc error occurs:
```c
void lv_image_decoder_init(uint32_t image_cache_size, uint32_t image_header_count)
{
lv_ll_init(img_decoder_ll_p, sizeof(lv_image_decoder_t));
/* Initialize the cache */
lv_image_cache_init(image_cache_size); // malloc(64) -> OK
lv_image_header_cache_init(image_header_count); // malloc(64) -> fail
}
```
### Fault log
```
lv_malloc: alloc of 1796 size succeeded - lv_mem.c:71
lv_malloc: alloc of 24 size succeeded - lv_mem.c:71
lv_malloc: alloc of 32 size succeeded - lv_mem.c:71
lv_malloc: alloc of 64 size succeeded - lv_mem.c:71
lv_malloc: alloc of 64 size failed - lv_mem.c:71
[Error] (0.000, +0) alloc_cb: Asserted at expression: res != NULL (Out of memory) lv_cache_lru_rb.c:190
[Error] (0.000, +0) alloc_cb: malloc failed lv_cache_lru_rb.c:192
[Error] (0.000, +0) lv_cache_create: Asserted at expression: cache != NULL (Out of memory) lv_cache.c:51
lv_malloc: alloc of 32 size failed - lv_mem.c:71
[Error] (0.000, +0) lv_image_decoder_create: Asserted at expression: decoder != NULL (Out of memory) lv_image_decoder.c:175
[Error] (0.000, +0) lv_bin_decoder_init: Asserted at expression: decoder != NULL (Out of memory) lv_bin_decoder.c:100
lv_malloc: alloc of 804 size failed - lv_mem.c:71
[00:00:00.687,866] <err> os: ***** BUS FAULT *****
[00:00:00.687,896] <err> os: Precise data bus error
[00:00:00.687,896] <err> os: BFAR Address: 0x28808fa
[00:00:00.687,927] <err> os: r0/a1: 0x028808f3 r1/a2: 0x0000005a r2/a3: 0x2000b080
[00:00:00.687,927] <err> os: r3/a4: 0x028808f3 r12/ip: 0x00000000 r14/lr: 0x0000894f
[00:00:00.687,957] <err> os: xpsr: 0x21000000
[00:00:00.687,957] <err> os: Faulting instruction address (r15/pc): 0x00029b86
[00:00:00.687,988] <err> os: >>> ZEPHYR FATAL ERROR 25: Unknown error on CPU 0
[00:00:00.688,018] <err> os: Current thread: 0x200010c8 (main)
[00:00:00.821,044] <err> os: Halting system
```
### prj.conf
```conf
CONFIG_DISPLAY=y
CONFIG_SPI=y
CONFIG_LVGL=y
CONFIG_GPIO=y
CONFIG_MIPI_DBI=y
CONFIG_MIPI_DBI_SPI=y
# Console and logging support
CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=y
CONFIG_SERIAL=y
CONFIG_LOG=y
CONFIG_PRINTK=y
CONFIG_MAIN_STACK_SIZE=4096
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=4096
CONFIG_HEAP_MEM_POOL_SIZE=65536
CONFIG_MPU_ALLOW_FLASH_WRITE=y
CONFIG_HW_STACK_PROTECTION=n # Temporarily disable for debugging
CONFIG_DISPLAY=y
CONFIG_DISPLAY_LOG_LEVEL_ERR=y
```
### DeviceTree overlay
```dts
/ {
chosen {
zephyr,display = &ili9341;
};
mipi_dbi {
compatible = "zephyr,mipi-dbi-spi";
dc-gpios = <&gpio1 11 GPIO_ACTIVE_HIGH>; // P1.04
reset-gpios = <&gpio1 10 GPIO_ACTIVE_LOW>; // P1.03
write-only;
#address-cells = <1>;
#size-cells = <0>;
spi-dev = <&spi1>;
pinctrl-0 = <&spi1_default>;
pinctrl-names = "default";
ili9341: ili9341@0 {
compatible = "ilitek,ili9341";
reg = <0>;
mipi-max-frequency = <4000000>;
width = <240>;
height = <320>;
rotation = <180>;
...
};
};
};
&spi1 {
status = "okay";
cs-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>; // P1.05
pinctrl-0 = <&spi1_default>;
pinctrl-1 = <&spi1_sleep>;
pinctrl-names = "default", "sleep";
};
```
### What I tried
* Verified the SPI pins & connections
* Display initializes correctly (backlight on, no SPI errors)
* Modified `CONFIG_HEAP_MEM_POOL_SIZE` in `prj.conf`
* Modified `CONFIG_MAIN_STACK_SIZE` in `prj.conf`
Any hints or guidance would be much appreciated!
Thanks in advance,
Niels Ouvrard
