The PD state machine checks this variable to decide how to handle power negotiation.

/* In usb_pd_policy.c */
void pd_check_power_role(int port)
if (pp_var_usb_rvp) 
        /*
         * RVP Feature: 
         * RVPs often act as a dedicated Source (provider) or Sink (consumer)
         * depending on the connected peripheral. We force 'Source' 
         * capability to power attached debug accessories.
         */
        pd_set_power_role(port, PD_ROLE_SOURCE);
        pd_set_max_voltage(port, 20000); // Allow 20V for validation
     else 
        /*
         * Production Feature:
         * Use standard dual-role (DRP) or specific OEM battery limits.
         */
        pd_set_power_role(port, PD_ROLE_DRP);
        pd_set_max_voltage(port, DEFAULT_BATTERY_MAX_VOLTAGE);

You’ve come across the string pp-var-usb-rvp and can’t find a datasheet, product listing, or manual that explains it. You’re not alone – sometimes hardware engineers, hobbyists, or system integrators use cryptic internal codes. Let’s break down what this could mean, and how to approach unknown identifiers like this one.

Field: Petroleum Chemistry / Environmental Science
Full Form: Reid Vapor Pressure

Definition:
RVP is a measure of the volatility of gasoline and other petroleum products. It indicates the pressure exerted by the vapor above a liquid fuel at 100°F (37.8°C) in a standardized test.

Key Points:

Example: If you fill your car with a “summer blend” gasoline, its RVP is lower (~9 psi) than winter blend (~13 psi), meaning it won’t evaporate as easily on a hot day, reducing air pollution.

In the board configuration header (e.g., board.h or config.h):

/*
 * pp-var-usb-rvp
 * Enables Reference Validation Platform (RVP) specific USB-PD behavior.
 * Value: 
 *   0 - Production behavior (Default).
 *   1 - RVP behavior (usually auto-detected via GPIO strap).
 */
#define CONFIG_USB_PD_RVP_SUPPORT
#ifdef CONFIG_USB_PD_RVP_SUPPORT
extern int pp_var_usb_rvp;
#endif