| /* |
| * Copyright (c) 2019, ARM Limited and Contributors. All rights reserved. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| #ifndef ARM_TRUSTED_FIRMWARE_EXPORT_LIB_BL_AUX_PARAMS_EXP_H |
| #define ARM_TRUSTED_FIRMWARE_EXPORT_LIB_BL_AUX_PARAMS_EXP_H |
| |
| /* EXPORT HEADER -- See include/export/README for details! -- EXPORT HEADER */ |
| |
| #include "../../drivers/gpio_exp.h" |
| |
| /* |
| * This API implements a lightweight parameter passing mechanism that can be |
| * used to pass SoC Firmware configuration data from BL2 to BL31 by platforms or |
| * configurations that do not want to depend on libfdt. It is structured as a |
| * singly-linked list of parameter structures that all share the same common |
| * header but may have different (and differently-sized) structure bodies after |
| * that. The header contains a type field to indicate the parameter type (which |
| * is used to infer the structure length and how to interpret its contents) and |
| * a next pointer which contains the absolute physical address of the next |
| * parameter structure. The next pointer in the last structure block is set to |
| * NULL. The picture below shows how the parameters are kept in memory. |
| * |
| * head of list ---> +----------------+ --+ |
| * | type | | |
| * +----------------+ |--> struct bl_aux_param |
| * +----| next | | |
| * | +----------------+ --+ |
| * | | parameter data | |
| * | +----------------+ |
| * | |
| * +--> +----------------+ --+ |
| * | type | | |
| * +----------------+ |--> struct bl_aux_param |
| * NULL <---| next | | |
| * +----------------+ --+ |
| * | parameter data | |
| * +----------------+ |
| * |
| * Note: The SCTLR_EL3.A bit (Alignment fault check enable) is set in TF-A, so |
| * BL2 must ensure that each parameter struct starts on a 64-bit aligned address |
| * to avoid alignment faults. Parameters may be allocated in any address range |
| * accessible at the time of BL31 handoff (e.g. SRAM, DRAM, SoC-internal scratch |
| * registers, etc.), in particular address ranges that may not be mapped in |
| * BL31's page tables, so the parameter list must be parsed before the MMU is |
| * enabled and any information that is required at a later point should be |
| * deep-copied out into BL31-internal data structures. |
| */ |
| |
| enum bl_aux_param_type { |
| BL_AUX_PARAM_NONE = 0, |
| BL_AUX_PARAM_VENDOR_SPECIFIC_FIRST = 0x1, |
| /* 0x1 - 0x7fffffff can be used by vendor-specific handlers. */ |
| BL_AUX_PARAM_VENDOR_SPECIFIC_LAST = 0x7fffffff, |
| BL_AUX_PARAM_GENERIC_FIRST = 0x80000001, |
| BL_AUX_PARAM_COREBOOT_TABLE = BL_AUX_PARAM_GENERIC_FIRST, |
| /* 0x80000001 - 0xffffffff are reserved for the generic handler. */ |
| BL_AUX_PARAM_GENERIC_LAST = 0xffffffff, |
| /* Top 32 bits of the type field are reserved for future use. */ |
| }; |
| |
| /* common header for all BL aux parameters */ |
| struct bl_aux_param_header { |
| uint64_t type; |
| uint64_t next; |
| }; |
| |
| /* commonly useful parameter structures that can be shared by multiple types */ |
| struct bl_aux_param_uint64 { |
| struct bl_aux_param_header h; |
| uint64_t value; |
| }; |
| |
| struct bl_aux_gpio_info { |
| uint8_t polarity; |
| uint8_t direction; |
| uint8_t pull_mode; |
| uint8_t reserved; |
| uint32_t index; |
| }; |
| |
| struct bl_aux_param_gpio { |
| struct bl_aux_param_header h; |
| struct bl_aux_gpio_info gpio; |
| }; |
| |
| #endif /* ARM_TRUSTED_FIRMWARE_EXPORT_LIB_BL_AUX_PARAMS_EXP_H */ |