diff options
| -rw-r--r-- | docs/specs/fw_cfg.txt | 85 | ||||
| -rw-r--r-- | include/hw/nvram/fw_cfg.h | 129 |
2 files changed, 130 insertions, 84 deletions
diff --git a/docs/specs/fw_cfg.txt b/docs/specs/fw_cfg.txt index b8c794f546..2099ad9a4d 100644 --- a/docs/specs/fw_cfg.txt +++ b/docs/specs/fw_cfg.txt @@ -192,90 +192,7 @@ To check the result, read the "control" field: today due to implementation not being async, but may in the future). -= Host-side API = - -The following functions are available to the QEMU programmer for adding -data to a fw_cfg device during guest initialization (see fw_cfg.h for -each function's complete prototype): - -== fw_cfg_add_bytes() == - -Given a selector key value, starting pointer, and size, create an item -as a raw "blob" of the given size, available by selecting the given key. -The data referenced by the starting pointer is only linked, NOT copied, -into the data structure of the fw_cfg device. - -== fw_cfg_add_string() == - -Instead of a starting pointer and size, this function accepts a pointer -to a NUL-terminated ascii string, and inserts a newly allocated copy of -the string (including the NUL terminator) into the fw_cfg device data -structure. - -== fw_cfg_add_iXX() == - -Insert an XX-bit item, where XX may be 16, 32, or 64. These functions -will convert a 16-, 32-, or 64-bit integer to little-endian, then add -a dynamically allocated copy of the appropriately sized item to fw_cfg -under the given selector key value. - -== fw_cfg_modify_iXX() == - -Modify the value of an XX-bit item (where XX may be 16, 32, or 64). -Similarly to the corresponding fw_cfg_add_iXX() function set, convert -a 16-, 32-, or 64-bit integer to little endian, create a dynamically -allocated copy of the required size, and replace the existing item at -the given selector key value with the newly allocated one. The previous -item, assumed to have been allocated during an earlier call to -fw_cfg_add_iXX() or fw_cfg_modify_iXX() (of the same width XX), is freed -before the function returns. - -== fw_cfg_add_file() == - -Given a filename (i.e., fw_cfg item name), starting pointer, and size, -create an item as a raw "blob" of the given size. Unlike fw_cfg_add_bytes() -above, the next available selector key (above 0x0020, FW_CFG_FILE_FIRST) -will be used, and a new entry will be added to the file directory structure -(at key 0x0019), containing the item name, blob size, and automatically -assigned selector key value. The data referenced by the starting pointer -is only linked, NOT copied, into the fw_cfg data structure. - -== fw_cfg_add_file_callback() == - -Like fw_cfg_add_file(), but additionally sets pointers to a callback -function (and opaque argument), which will be executed host-side by -QEMU each time a byte is read by the guest from this particular item. - -NOTE: The callback function is given the opaque argument set by -fw_cfg_add_file_callback(), but also the current data offset, -allowing it the option of only acting upon specific offset values -(e.g., 0, before the first data byte of the selected item is -returned to the guest). - -== fw_cfg_modify_file() == - -Given a filename (i.e., fw_cfg item name), starting pointer, and size, -completely replace the configuration item referenced by the given item -name with the new given blob. If an existing blob is found, its -callback information is removed, and a pointer to the old data is -returned to allow the caller to free it, helping avoid memory leaks. -If a configuration item does not already exist under the given item -name, a new item will be created as with fw_cfg_add_file(), and NULL -is returned to the caller. In any case, the data referenced by the -starting pointer is only linked, NOT copied, into the fw_cfg data -structure. - -== fw_cfg_add_callback() == - -Like fw_cfg_add_bytes(), but additionally sets pointers to a callback -function (and opaque argument), which will be executed host-side by -QEMU each time a guest-side write operation to this particular item -completes fully overwriting the item's data. - -NOTE: This function is deprecated, and will be completely removed -starting with QEMU v2.4. - -== Externally Provided Items == += Externally Provided Items = As of v2.4, "file" fw_cfg items (i.e., items with selector keys above FW_CFG_FILE_FIRST, and with a corresponding entry in the fw_cfg file diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h index ee0cd8adb3..4b5e196d17 100644 --- a/include/hw/nvram/fw_cfg.h +++ b/include/hw/nvram/fw_cfg.h @@ -73,19 +73,148 @@ typedef struct FWCfgDmaAccess { typedef void (*FWCfgCallback)(void *opaque, uint8_t *data); typedef void (*FWCfgReadCallback)(void *opaque, uint32_t offset); +/** + * fw_cfg_add_bytes: + * @s: fw_cfg device being modified + * @key: selector key value for new fw_cfg item + * @data: pointer to start of item data + * @len: size of item data + * + * Add a new fw_cfg item, available by selecting the given key, as a raw + * "blob" of the given size. The data referenced by the starting pointer + * is only linked, NOT copied, into the data structure of the fw_cfg device. + */ void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len); + +/** + * fw_cfg_add_string: + * @s: fw_cfg device being modified + * @key: selector key value for new fw_cfg item + * @value: NUL-terminated ascii string + * + * Add a new fw_cfg item, available by selecting the given key. The item + * data will consist of a dynamically allocated copy of the provided string, + * including its NUL terminator. + */ void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value); + +/** + * fw_cfg_add_i16: + * @s: fw_cfg device being modified + * @key: selector key value for new fw_cfg item + * @value: 16-bit integer + * + * Add a new fw_cfg item, available by selecting the given key. The item + * data will consist of a dynamically allocated copy of the given 16-bit + * value, converted to little-endian representation. + */ void fw_cfg_add_i16(FWCfgState *s, uint16_t key, uint16_t value); + +/** + * fw_cfg_modify_i16: + * @s: fw_cfg device being modified + * @key: selector key value for new fw_cfg item + * @value: 16-bit integer + * + * Replace the fw_cfg item available by selecting the given key. The new + * data will consist of a dynamically allocated copy of the given 16-bit + * value, converted to little-endian representation. The data being replaced, + * assumed to have been dynamically allocated during an earlier call to + * either fw_cfg_add_i16() or fw_cfg_modify_i16(), is freed before returning. + */ void fw_cfg_modify_i16(FWCfgState *s, uint16_t key, uint16_t value); + +/** + * fw_cfg_add_i32: + * @s: fw_cfg device being modified + * @key: selector key value for new fw_cfg item + * @value: 32-bit integer + * + * Add a new fw_cfg item, available by selecting the given key. The item + * data will consist of a dynamically allocated copy of the given 32-bit + * value, converted to little-endian representation. + */ void fw_cfg_add_i32(FWCfgState *s, uint16_t key, uint32_t value); + +/** + * fw_cfg_add_i64: + * @s: fw_cfg device being modified + * @key: selector key value for new fw_cfg item + * @value: 64-bit integer + * + * Add a new fw_cfg item, available by selecting the given key. The item + * data will consist of a dynamically allocated copy of the given 64-bit + * value, converted to little-endian representation. + */ void fw_cfg_add_i64(FWCfgState *s, uint16_t key, uint64_t value); + +/** + * fw_cfg_add_file: + * @s: fw_cfg device being modified + * @filename: name of new fw_cfg file item + * @data: pointer to start of item data + * @len: size of item data + * + * Add a new NAMED fw_cfg item as a raw "blob" of the given size. The data + * referenced by the starting pointer is only linked, NOT copied, into the + * data structure of the fw_cfg device. + * The next available (unused) selector key starting at FW_CFG_FILE_FIRST + * will be used; also, a new entry will be added to the file directory + * structure residing at key value FW_CFG_FILE_DIR, containing the item name, + * data size, and assigned selector key value. + */ void fw_cfg_add_file(FWCfgState *s, const char *filename, void *data, size_t len); + +/** + * fw_cfg_add_file_callback: + * @s: fw_cfg device being modified + * @filename: name of new fw_cfg file item + * @callback: callback function + * @callback_opaque: argument to be passed into callback function + * @data: pointer to start of item data + * @len: size of item data + * + * Add a new NAMED fw_cfg item as a raw "blob" of the given size. The data + * referenced by the starting pointer is only linked, NOT copied, into the + * data structure of the fw_cfg device. + * The next available (unused) selector key starting at FW_CFG_FILE_FIRST + * will be used; also, a new entry will be added to the file directory + * structure residing at key value FW_CFG_FILE_DIR, containing the item name, + * data size, and assigned selector key value. + * Additionally, set a callback function (and argument) to be called each + * time a byte is read by the guest from this particular item, or, in the + * case of DMA, each time a read or skip request overlaps with the valid + * offset range of the item. + * NOTE: In addition to the opaque argument set here, the callback function + * takes the current data offset as an additional argument, allowing it the + * option of only acting upon specific offset values (e.g., 0, before the + * first data byte of the selected item is returned to the guest). + */ void fw_cfg_add_file_callback(FWCfgState *s, const char *filename, FWCfgReadCallback callback, void *callback_opaque, void *data, size_t len); + +/** + * fw_cfg_modify_file: + * @s: fw_cfg device being modified + * @filename: name of new fw_cfg file item + * @data: pointer to start of item data + * @len: size of item data + * + * Replace a NAMED fw_cfg item. If an existing item is found, its callback + * information will be cleared, and a pointer to its data will be returned + * to the caller, so that it may be freed if necessary. If an existing item + * is not found, this call defaults to fw_cfg_add_file(), and NULL is + * returned to the caller. + * In either case, the new item data is only linked, NOT copied, into the + * data structure of the fw_cfg device. + * + * Returns: pointer to old item's data, or NULL if old item does not exist. + */ void *fw_cfg_modify_file(FWCfgState *s, const char *filename, void *data, size_t len); + FWCfgState *fw_cfg_init_io_dma(uint32_t iobase, uint32_t dma_iobase, AddressSpace *dma_as); FWCfgState *fw_cfg_init_io(uint32_t iobase); |