/** * struct resource_table - firmware resource table header * @ver: version number * @num: number of resource entries * @reserved: reserved (must be zero) * @offset: array of offsets pointing at the various resource entries * * A resource table is essentially a list of system resources required * by the remote processor. It may also include configuration entries. * If needed, the remote processor firmware should contain this table * as a dedicated ".resource_table" ELF section. * * Some resources entries are mere announcements, where the host is informed * of specific remoteproc configuration. Other entries require the host to * do something (e.g. allocate a system resource). Sometimes a negotiation * is expected, where the firmware requests a resource, and once allocated, * the host should provide back its details (e.g. address of an allocated * memory region). * * The header of the resource table, as expressed by this structure, * contains a version number (should we need to change this format in the * future), the number of available resource entries, and their offsets * in the table. * * Immediately following this header are the resource entries themselves, * each of which begins with a resource entry header (as described below). */ structresource_table { u32 ver; u32 num; u32 reserved[2]; u32 offset[]; } __packed;
/** * struct fw_rsc_hdr - firmware resource entry header * @type: resource type * @data: resource data * * Every resource entry begins with a 'struct fw_rsc_hdr' header providing * its @type. The content of the entry itself will immediately follow * this header, and it should be parsed according to the resource type. */ structfw_rsc_hdr { u32 type; u8 data[]; } __packed;
/** * enum fw_resource_type - types of resource entries * * @RSC_CARVEOUT: request for allocation of a physically contiguous * memory region. * @RSC_DEVMEM: request to iommu_map a memory-based peripheral. * @RSC_TRACE: announces the availability of a trace buffer into which * the remote processor will be writing logs. * @RSC_VDEV: declare support for a virtio device, and serve as its * virtio header. * @RSC_LAST: just keep this one at the end of standard resources * @RSC_VENDOR_START: start of the vendor specific resource types range * @RSC_VENDOR_END: end of the vendor specific resource types range * * For more details regarding a specific resource type, please see its * dedicated structure below. * * Please note that these values are used as indices to the rproc_handle_rsc * lookup table, so please keep them sane. Moreover, @RSC_LAST is used to * check the validity of an index before the lookup table is accessed, so * please update it as needed. */ enumfw_resource_type { RSC_CARVEOUT = 0, RSC_DEVMEM = 1, RSC_TRACE = 2, RSC_VDEV = 3, RSC_LAST = 4, RSC_VENDOR_START = 128, RSC_VENDOR_END = 512, };
/** * struct fw_rsc_carveout - physically contiguous memory request * @da: device address * @pa: physical address * @len: length (in bytes) * @flags: iommu protection flags * @reserved: reserved (must be zero) * @name: human-readable name of the requested memory region * * This resource entry requests the host to allocate a physically contiguous * memory region. * * These request entries shonuld precede other firmware resource entries, * as other entries might request placing other data objects inside * these memory regions (e.g. data/code segments, trace resource entries, ...). * * Allocating memory this way helps utilizing the reserved physical memory * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB * pressure is important; it may have a substantial impact on performance. * * If the firmware is compiled with static addresses, then @da should specify * the expected device address of this memory region. If @da is set to * FW_RSC_ADDR_ANY, then the host will dynamically allocate it, and then * overwrite @da with the dynamically allocated address. * * We will always use @da to negotiate the device addresses, even if it * isn't using an iommu. In that case, though, it will obviously contain * physical addresses. * * Some remote processors needs to know the allocated physical address * even if they do use an iommu. This is needed, e.g., if they control * hardware accelerators which access the physical memory directly (this * is the case with OMAP4 for instance). In that case, the host will * overwrite @pa with the dynamically allocated physical address. * Generally we don't want to expose physical addresses if we don't have to * (remote processors are generally _not_ trusted), so we might want to * change this to happen _only_ when explicitly required by the hardware. * * @flags is used to provide IOMMU protection flags, and @name should * (optionally) contain a human readable name of this carveout region * (mainly for debugging purposes). */ structfw_rsc_carveout { u32 da; u32 pa; u32 len; u32 flags; u32 reserved; u8 name[32]; } __packed;
/** * struct fw_rsc_devmem - iommu mapping request * @da: device address * @pa: physical address * @len: length (in bytes) * @flags: iommu protection flags * @reserved: reserved (must be zero) * @name: human-readable name of the requested region to be mapped * * This resource entry requests the host to iommu map a physically contiguous * memory region. This is needed in case the remote processor requires * access to certain memory-based peripherals; _never_ use it to access * regular memory. * * This is obviously only needed if the remote processor is accessing memory * via an iommu. * * @da should specify the required device address, @pa should specify * the physical address we want to map, @len should specify the size of * the mapping and @flags is the IOMMU protection flags. As always, @name may * (optionally) contain a human readable name of this mapping (mainly for * debugging purposes). * * Note: at this point we just "trust" those devmem entries to contain valid * physical addresses, but this isn't safe and will be changed: eventually we * want remoteproc implementations to provide us ranges of physical addresses * the firmware is allowed to request, and not allow firmwares to request * access to physical addresses that are outside those ranges. */ structfw_rsc_devmem { u32 da; u32 pa; u32 len; u32 flags; u32 reserved; u8 name[32]; } __packed;
/** * struct fw_rsc_trace - trace buffer declaration * @da: device address * @len: length (in bytes) * @reserved: reserved (must be zero) * @name: human-readable name of the trace buffer * * This resource entry provides the host information about a trace buffer * into which the remote processor will write log messages. * * @da specifies the device address of the buffer, @len specifies * its size, and @name may contain a human readable name of the trace buffer. * * After booting the remote processor, the trace buffers are exposed to the * user via debugfs entries (called trace0, trace1, etc..). */ structfw_rsc_trace { u32 da; u32 len; u32 reserved; u8 name[32]; } __packed;
/** * struct fw_rsc_vdev_vring - vring descriptor entry * @da: device address * @align: the alignment between the consumer and producer parts of the vring * @num: num of buffers supported by this vring (must be power of two) * @notifyid is a unique rproc-wide notify index for this vring. This notify * index is used when kicking a remote processor, to let it know that this * vring is triggered. * @pa: physical address * * This descriptor is not a resource entry by itself; it is part of the * vdev resource type (see below). * * Note that @da should either contain the device address where * the remote processor is expecting the vring, or indicate that * dynamically allocation of the vring's device address is supported. */ structfw_rsc_vdev_vring { u32 da; u32 align; u32 num; u32 notifyid; u32 pa; } __packed;
/** * struct fw_rsc_vdev - virtio device header * @id: virtio device id (as in virtio_ids.h) * @notifyid is a unique rproc-wide notify index for this vdev. This notify * index is used when kicking a remote processor, to let it know that the * status/features of this vdev have changes. * @dfeatures specifies the virtio device features supported by the firmware * @gfeatures is a place holder used by the host to write back the * negotiated features that are supported by both sides. * @config_len is the size of the virtio config space of this vdev. The config * space lies in the resource table immediate after this vdev header. * @status is a place holder where the host will indicate its virtio progress. * @num_of_vrings indicates how many vrings are described in this vdev header * @reserved: reserved (must be zero) * @vring is an array of @num_of_vrings entries of 'struct fw_rsc_vdev_vring'. * * This resource is a virtio device header: it provides information about * the vdev, and is then used by the host and its peer remote processors * to negotiate and share certain virtio properties. * * By providing this resource entry, the firmware essentially asks remoteproc * to statically allocate a vdev upon registration of the rproc (dynamic vdev * allocation is not yet supported). * * Note: unlike virtualization systems, the term 'host' here means * the Linux side which is running remoteproc to control the remote * processors. We use the name 'gfeatures' to comply with virtio's terms, * though there isn't really any virtualized guest OS here: it's the host * which is responsible for negotiating the final features. * Yeah, it's a bit confusing. * * Note: immediately following this structure is the virtio config space for * this vdev (which is specific to the vdev; for more info, read the virtio * spec). the size of the config space is specified by @config_len. */ structfw_rsc_vdev { u32 id; u32 notifyid; u32 dfeatures; u32 gfeatures; u32 config_len; u8 status; u8 num_of_vrings; u8 reserved[2]; structfw_rsc_vdev_vringvring[]; } __packed;
/** ****************************************************************************** * @file rsc_table.c * @author MCD Application Team * @brief Ressource table * * This file provides a default resource table requested by remote proc to * load the elf file. It also allows to add debug trace using a shared buffer. * ****************************************************************************** * @attention * * Copyright (c) 2021 STMicroelectronics. * All rights reserved. * * This software is licensed under terms that can be found in the LICENSE file * in the root directory of this software component. * If no LICENSE file comes with this software, it is provided AS-IS. * ****************************************************************************** */
/* Since GCC is not initializing the resource_table at startup, it is declared as volatile to avoid compiler optimization * for the CM4 (see resource_table_init() below) */ volatilestructshared_resource_table __resource __attribute__((used)) resource_table; #else CONST structshared_resource_table __resource __attribute__((used)) resource_table = { #endif #elif defined(__ICCARM__) __root CONST structshared_resource_tableresource_table @ ".resource_table" = { #endif
voidresource_table_init(int RPMsgRole, void **table_ptr, int *length) {
#if !defined (LINUX_RPROC_MASTER) #if defined (__GNUC__) && ! defined (__CC_ARM) #ifdef VIRTIO_MASTER_ONLY
/* * Currently the GCC linker doesn't initialize the resource_table global variable at startup * it is done here by the master application. */ memset(&resource_table, '\0', sizeof(struct shared_resource_table)); resource_table.num = 1; resource_table.version = 1; resource_table.offset[0] = offsetof(struct shared_resource_table, vdev);
/* * Copyright (c) 2021 STMicroelectronics. * All rights reserved. * * This software is licensed under terms that can be found in the LICENSE file * in the root directory of this software component. * If no LICENSE file comes with this software, it is provided AS-IS. * */
/* This file populates resource table for BM remote * for use by the Linux Master */
/** * struct fw_rsc_vdev - virtio device header * @id: virtio device id (as in virtio_ids.h) * @notifyid is a unique rproc-wide notify index for this vdev. This notify * index is used when kicking a remote remoteproc, to let it know that the * status/features of this vdev have changes. * @dfeatures specifies the virtio device features supported by the firmware * @gfeatures is a place holder used by the host to write back the * negotiated features that are supported by both sides. * @config_len is the size of the virtio config space of this vdev. The config * space lies in the resource table immediate after this vdev header. * @status is a place holder where the host will indicate its virtio progress. * @num_of_vrings indicates how many vrings are described in this vdev header * @reserved: reserved (must be zero) * @vring is an array of @num_of_vrings entries of 'struct fw_rsc_vdev_vring'. * * This resource is a virtio device header: it provides information about * the vdev, and is then used by the host and its peer remote remoteprocs * to negotiate and share certain virtio properties. * * By providing this resource entry, the firmware essentially asks remoteproc * to statically allocate a vdev upon registration of the rproc (dynamic vdev * allocation is not yet supported). * * Note: unlike virtualization systems, the term 'host' here means * the Linux side which is running remoteproc to control the remote * remoteprocs. We use the name 'gfeatures' to comply with virtio's terms, * though there isn't really any virtualized guest OS here: it's the host * which is responsible for negotiating the final features. * Yeah, it's a bit confusing. * * Note: immediately following this structure is the virtio config space for * this vdev (which is specific to the vdev; for more info, read the virtio * spec). the size of the config space is specified by @config_len. */ METAL_PACKED_BEGIN structfw_rsc_vdev { uint32_t type; // ← ST 在最前面加了 type！ uint32_t id; uint32_t notifyid; uint32_t dfeatures; uint32_t gfeatures; uint32_t config_len; uint8_t status; uint8_t num_of_vrings; uint8_t reserved[2]; structfw_rsc_vdev_vringvring[0];// 零长度柔性数组 } METAL_PACKED_END;
ST 的 fw_rsc_vdev 把 type 折叠进来了
这里有两点：
ST在 struct fw_rsc_vdev 的最前面加了 type 而 Linux 的 struct fw_rsc_vdev 没有 type（type 在独立的 struct fw_rsc_hdr 里）。但两者 on-wire 完全一致：
/** * struct fw_rsc_vdev_vring - vring descriptor entry * @da: device address * @align: the alignment between the consumer and producer parts of the vring * @num: num of buffers supported by this vring (must be power of two) * @notifyid is a unique rproc-wide notify index for this vring. This notify * index is used when kicking a remote remoteproc, to let it know that this * vring is triggered. * @reserved: reserved (must be zero) * * This descriptor is not a resource entry by itself; it is part of the * vdev resource type (see below). * * Note that @da should either contain the device address where * the remote remoteproc is expecting the vring, or indicate that * dynamically allocation of the vring's device address is supported. */ METAL_PACKED_BEGIN structfw_rsc_vdev_vring { uint32_t da; uint32_t align; uint32_t num; uint32_t notifyid; uint32_t reserved; } METAL_PACKED_END;
/** * struct fw_rsc_trace - trace buffer declaration * @da: device address * @len: length (in bytes) * @reserved: reserved (must be zero) * @name: human-readable name of the trace buffer * * This resource entry provides the host information about a trace buffer * into which the remote remoteproc will write log messages. * * @da specifies the device address of the buffer, @len specifies * its size, and @name may contain a human readable name of the trace buffer. * * After booting the remote remoteproc, the trace buffers are exposed to the * user via debugfs entries (called trace0, trace1, etc..). */ METAL_PACKED_BEGIN structfw_rsc_trace { uint32_t type; uint32_t da; uint32_t len; uint32_t reserved; uint8_t name[RPROC_MAX_NAME_LEN]; } METAL_PACKED_END;
/* Since GCC is not initializing the resource_table at startup, it is declared as volatile to avoid compiler optimization * for the CM4 (see resource_table_init() below) */ volatilestructshared_resource_table __resource __attribute__((used)) resource_table; #else CONST structshared_resource_table __resource __attribute__((used)) resource_table = { #endif #elif defined(__ICCARM__) __root CONST structshared_resource_tableresource_table @ ".resource_table" = { #endif
voidresource_table_init(int RPMsgRole, void **table_ptr, int *length) {
#if !defined (LINUX_RPROC_MASTER) #if defined (__GNUC__) && ! defined (__CC_ARM) #ifdef VIRTIO_MASTER_ONLY
/* * Currently the GCC linker doesn't initialize the resource_table global variable at startup * it is done here by the master application. */ memset(&resource_table, '\0', sizeof(struct shared_resource_table)); resource_table.num = 1; resource_table.version = 1; resource_table.offset[0] = offsetof(struct shared_resource_table, vdev);
