Its purpose is to ensure that all data transmitted between the server and the client remains private and secure from eavesdropping, tampering, or forgery. While SSL itself has been deprecated in favor of its successor, TLS (Transport Layer Security), the term “SSL” is still commonly used to refer to the broader concept of secure network communication.

Overall Idea Avoid immediate trading post-result; monitor price behaviour instead. Monitor for retracement and consistent trends See quarterly result and shortlist high growth stocks Fundamental Analysis is must because if the analysis is even wrong but fundamentals are strong then the loss will be minimal. So, less chance of being wrong. Filter by Fundamentals High Growth Criteria: Quarterly sales growth YoY > 10%. Quarterly profit growth YoY > 10%. Sales and profit in the latest quarter should be the highest compared to previous quarters. See percent change in growth of past 3 years ...

Alt + H = Horizontal line Alt + V = Vertical line Alt + T = Trendline Alt + F = Fibonacci Alt + C = Crossline Alt + I = Invert chart Alt + S = Link to your chart References https://www.tradingview.com/charting-library-docs/latest/getting_started/Shortcuts/

Problem In bootloader the environment variables are accessible. The values could be accessed and modified perfectly from bootloader cli (hush shell). When booting to the linux kernel and accessing from bash shell (userspace) through fw_printenv the environment variables are not accessible. Getting following logs: Warning: Bad CRC, using default environment Setup: Using MMC storage The /etc/fw_env.config file has following entry and the offset and size are same from uboot’s .config file /dev/mmcblk0p2 0x3f8000 0x8000 Uboot Environment in RK3588 Uboot Config config ENV_OFFSET hex "Environment offset" depends on !ENV_IS_IN_UBI depends on !ENV_IS_NOWHERE || ENVF default 0x0 if ENVF default 0x3f8000 help Offset from the start of the device (or partition) config ENV_SIZE hex "Environment size" default 0x8000 help Size of the environment storage area Parameters CONFIG_ENV_SIZE=0x8000 --> 32K CONFIG_ENV_OFFSET=0x3f8000 --> 4096-32=4064 4096K=4M u-boot/tools/env/fw_env.c Either crc0_ok = (crc0 == *environment.crc); is invalid ...

This guide provides step-by-step instructions for setting up consistent formatting, rules checking, and documentation for C/C++ code using clang-format, clang-tidy, and Doxygen in VS Code. Follow this guide to ensure uniformity across the team. 1. Prerequisites Before starting, ensure you have the following tools installed: VS Code (latest version) Extensions for VS Code: C/C++ (Microsoft) Doxygen Documentation Generator Command-line tools: clang-format clang-tidy doxygen Python (for pre-commit hooks) 2. Auto-Formatting Using clang-format clang-format is used for consistent code formatting. ...

Number Macro Log Level Description Equivalent 0 pr_emerg Emergency System is unusable. KERN_EMERG 1 pr_alert Alert Action must be taken immediately. KERN_ALERT 2 pr_crit Critical Critical conditions. KERN_CRIT 3 pr_err Error Error conditions. KERN_ERR 4 pr_warn Warning Warning conditions. KERN_WARNING 5 pr_notice Notice Normal but significant condition. KERN_NOTICE 6 pr_info Informational Informational messages. KERN_INFO 7 pr_debug pr_devel Debug Debugging messages. pr_debug() and pr_devel() if DEBUG is defined KERN_DEBUG The number corresponds to the log level used by the Linux kernel, with lower numbers indicating higher severity. For example, if the log level is set to 4 (Warning), only messages from pr_emerg to pr_warn will appear in the system logs. Default log level is generally set to 6. You can check the current console_loglevel with: cat /proc/sys/kernel/printk 4 4 1 7 echo 8 > /proc/sys/kernel/printk dmesg -n 5 Reference https://www.kernel.org/doc/html/next/core-api/printk-basics.html

Overview Get the final files into a directory eg. target and treat it as root(/) directory of target board/system. Generate users eg. root, admin, ssh, etc Generate device lists Clean few files Generate ext image using mkfs Taking reference from buildroot common.mk and ext2.mk scripts/makedevs -d output/build/buildroot-fs/full_devices_table.txt output/build/buildroot-fs/ext2/target mkfs.ext4 -d output/build/buildroot-fs/ext2/target -r 1 -N 0 -m 5 -L rootfs -O ^64bit output/images/rootfs.ext2 2G # Fakeroot execution complete /opt/rk3588_nvrx/host/sbin/resize2fs -M output/images/rootfs.ext2 /opt/rk3588_nvrx/host/sbin/e2fsck -fy /output/images/rootfs.ext2 /opt/rk3588_nvrx/host/sbin/resize2fs -M /output/images/rootfs.ext2 Fakeroot Script #!/bin/sh set -ex chown -h -R 0:0 $(TARGET) $(HOST_DIR)/bin/makedevs -d full_devices_table.txt $(TARGET) $(HOST_DIR)/sbin/mkfs.ext4 -d $(TARGET) -r 1 -N 0 -m 5 -L "rootfs" -O ^64bit rootfs.ext2 "2G" Post EXT4 $(HOST_DIR)/sbin/resize2fs -M rootfs.ext2 $(HOST_DIR)/sbin/e2fsck -fy rootfs.ext2 $(HOST_DIR)/sbin/tune2fs -m 5 rootfs.ext2 $(HOST_DIR)/sbin/resize2fs -M rootfs.ext2 Testing on Host sudo mount -o loop path/to/rootfs.ext4 /tmp/fs_path Makedevs Creates a batch of special files as specified in a device table. ...

Basics of I2C Overview Synchronous, multi-master, multi-slave serial bus. Half-duplex communication (bidirectional SDA line). Uses 2 wires: SCL (clock), SDA (data). Speeds: Standard (100 kHz), Fast (400 kHz), High-Speed (3.4 MHz). Physical Layer Open-drain outputs – requires pull-up resistors. 7-bit or 10-bit addressing (supports up to 128/1024 devices). Data Frame Structure Start condition: SDA ↓ while SCL is high. Address frame: 7/10-bit address + R/W bit. ACK/NACK: Slave pulls SDA low to acknowledge. Data frames (8-bit chunks, MSB-first). Stop condition: SDA ↑ while SCL is high. Start | Address | Read/Write | ACK/NACK | Data | Stop Key Features Clock stretching: Slaves can hold SCL low to pause communication. Multi-master arbitration: Masters detect collisions via SDA monitoring. Speeds: Standard (100 kbps), Fast (400 kbps), High-Speed (3.4 Mbps). Use Cases Sensors (temperature, accelerometers). EEPROMs, RTC (Real-Time Clock) modules. Device Tree TODO Writing client device drivers TODO I2C-Tools Package in Userspace Useful for debugging, testing, some simple prototyping Accesses the I²C bus via /dev/i2c-0, /dev/i2c-1… Assume devices have registers, SMBus-like i2cdetect scan an I2C bus for devices No guarantee it works (I²C is not discoverable by the spec) [rishav] ➜ ~ i2cdetect -l i2c-0 i2c i915 gmbus dpc I2C adapter i2c-1 i2c i915 gmbus dpb I2C adapter i2c-2 i2c i915 gmbus dpd I2C adapter i2c-3 i2c AUX A/DDI A/PHY A I2C adapter i2c-4 unknown Synopsys DesignWare I2C adapter N/A i2c-5 unknown Synopsys DesignWare I2C adapter N/A i2c-6 unknown SMBus I801 adapter at f040 N/A [rishav] ➜ ~ i2cdetect -y 2 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- 28 -- -- -- -- -- -- -- 30: -- -- -- UU -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- -- -- -- -- -- -- No response 28 Response from address 28 UU Address in use (by driver) i2cget, i2cset i2cget: read a register value i2cset: set a register value Can use various types of SMBus and I2C transactions Limited to 8-bit register address # i2cget -y 2 0x28 0x1b 0x21 # i2cset -y 2 0x28 0x55 # i2cdump dump value of all registers i2ctransfer i2ctransfer: the “swiss army knife of Linux I2C”, in userspace Example: reimplement the i2cget -y 2 0x28 0x1b command: # i2ctransfer -y 2 w1@0x28 0x1b r1@0x28 0x21 # w1@0x28 Write transaction, 1 byte, client address 0x28 0x1b Data to send in the write transaction r1@0x28 Read transaction, 1 byte, client address 0x28 Troubleshooting Return code from i2c_*() functions — Never ignore errors! Kernel logs i2c-tools Oscilloscope or logic analyzer No ACK from client - systematic Problem: a client never responds to transactions ...

Example Image Tree Source (.its) file /dts-v1/; / { description = "U-Boot FIT source file for arm"; images { uboot { data = /incbin/("uboot.img.enc"); type = "standalone"; arch = "arm64"; compression = "none"; load = <0xffffff00>; hash { algo = "sha256"; }; }; }; configurations { default = "conf"; conf { rollback-index = <0x00>; uboot = "uboot"; board-type = "MU_BOARD"; signature { algo = "sha256,rsa2048"; padding = "pss"; key-name-hint = "dev"; sign-images = "uboot"; }; }; }; }; References https://devicetree-specification.readthedocs.io/en/stable/index.html

Device Tree Standard Properties compatible The compatible property value consists of one or more strings that define the specific programming model for the device. This list of strings should be used by a client program for device driver selection. The property value consists of a concatenated list of null terminated strings, from most specific to most general. They allow a device to express its compatibility with a family of similar devices, potentially allowing a single device driver to match against several devices. ...