I want to switch the boot partition(emmc <-> nvme ssd) when the gpio value is low in cboot.
How do I get the gpio status and choose the boot partition in cboot?
The information as below.
Jetpack version : R32.4.4
Jetson device : Xavier NX, AGX Xavier, Nano
Thank you.
hello manny_wang,
please download L4T sources via download center, you may check the header file for the APIs to check GPIO status.
for example,
$L4T_Sources/r32.4.4/Linux_for_Tegra/source/public/cboot/bootloader/partner/t18x/cboot/include/dev/gpio.h
Hi JerryChang,
Thank you for your reply.
But I get the compile error as below when I include the “/dev/gpio.h” and use the apis.
/home/nvidia/Workspace/NVIDIA/SDKManager/SDK/JetPack_4.4.1_Linux_JETSON_XAVIER_NX/Linux_for_Tegra/cboot/bootloader/partner/t18x/cboot/top/main.c:74: undefined reference to `gpio_config’
/home/nvidia/Workspace/NVIDIA/SDKManager/SDK/JetPack_4.4.1_Linux_JETSON_XAVIER_NX/Linux_for_Tegra/cboot/bootloader/partner/t18x/cboot/top/main.c:76: undefined reference to `gpio_get’
Is it the static library?
If it does, I need to write the library name into Makefile, right?
hello manny_wang,
could you please try to include below header file for testing,
$L4T_Sources/r32.4.4/Linux_for_Tegra/source/public/cboot/bootloader/partner/common/include/drivers/tegrabl_gpio.h
please use this GPIO API for reading a GPIO pin state in CBoot.
for example,
static inline tegrabl_error_t gpio_read(struct gpio_driver *drv, uint32_t gpio_num, gpio_pin_state_t *state){...}
Hi JerryChang,
Which one is correct?
$L4T_Sources/r32.4.4/Linux_for_Tegra/source/public/cboot/bootloader/partner/t18x/cboot/include/dev/gpio.h
or
$L4T_Sources/r32.4.4/Linux_for_Tegra/source/public/cboot/bootloader/partner/common/include/drivers/tegrabl_gpio.h
thanks.
$L4T_Sources/r32.4.4/Linux_for_Tegra/source/public/cboot/bootloader/partner/common/include/drivers/tegrabl_gpio.h
Hi JerryChang,
I call the “tegrabl_gpio_driver_get” api in main.c file, and I get the panic error as below on boot.
how do i fix the problem? and what is the root cause?
hello manny_wang,
you may check you’re assign correct pin numbers.
this tegrabl_gpio_driver_get() API will retrieve a handle to a GPIO driver from its chip_id number.
Hi JerryChang,
The pin number’s value is 446.
The signal name is “I2C0_DOUT”(Pin# 193) in the ODM document.
There will get the error code, not the panic when I use the incorrect number, right?
hello manny_wang,
according to pinmux spreadsheets. the signal name is I2S0_DOUT for pin# 193, it is GPIO3_PT.06.
you may also refer to Xavier NX’s GPIO definition,
for example,
$L4T_Sources/r32.4.4/Linux_for_Tegra/source/public/kernel/nvidia/include/dt-bindings/gpio/tegra194-gpio.h
you’re correct this pin number is 446 form kernel side, which coming from ( (19 * 8) + 6) + 288 = 446.
however, you should note that there’re GPIO allocation ranges for kernel.
for example, you may found the kernel init messages to register these GPIO within the range.
[ 0.875748] gpiochip_setup_dev: registered GPIOs 288 to 511 on device: gpiochip0 (tegra-gpio)
according to Boot Flow, since you’re going to check the GPIO state in CBoot.
could you please revise the pin number as (19 * 8) + 6 = 158, for verification.
thanks
Hi JerryChang,
Before revise the pin number, I want to check the error message.
It happened panic when i use the " tegrabl_gpio_driver_get".
Maybe the root cause is NOT the pin number, right?
hello manny_wang,
ideally, it should return TEGRABL_ERR_NOT_FOUND if you’re assign incorrect pin number.
thanks
Hi JerryChang,
So, why do I get the panic?
The API can NOT use in lk_main function?
had you tried to revise the pin number as (19 * 8) + 6 = 158, for verification ?
Yes, I try it.
But the panic still happened when I use the “tegrabl_gpio_driver_get”.
hello manny_wang,
FYI,
it turns out CBoot can’t load NVMe, because it doesn’t have the NVMe driver.
Hi JerryChang,
OK. But I still want to know what is the root cause of panic issue.
Could you just tell me why do I get the panic when I use the “tegrabl_gpio_driver_get” API in lk_main function in main.c.
can you share the panic log?
can you share the change you made.
this is not kernel panic. this cboot panic.