/* * Functions to help device tree manipulation using libfdt. * It also provides functions to read entries from device tree proc * interface. * * Copyright 2008 IBM Corporation. * Authors: Jerone Young <jyoung5@us.ibm.com> * Hollis Blanchard <hollisb@us.ibm.com> * * This work is licensed under the GNU GPL license version 2 or later. * */ #include "qemu/osdep.h" #ifdef CONFIG_LINUX #include <dirent.h> #endif #include "qapi/error.h" #include "qemu/error-report.h" #include "qemu/option.h" #include "qemu/bswap.h" #include "sysemu/device_tree.h" #include "sysemu/sysemu.h" #include "hw/loader.h" #include "hw/boards.h" #include "qemu/config-file.h" #include <libfdt.h> #define FDT_MAX_SIZE 0x100000 void *create_device_tree(int *sizep) { void *fdt; int ret; *sizep = FDT_MAX_SIZE; fdt = g_malloc0(FDT_MAX_SIZE); ret = fdt_create(fdt, FDT_MAX_SIZE); if (ret < 0) { goto fail; } ret = fdt_finish_reservemap(fdt); if (ret < 0) { goto fail; } ret = fdt_begin_node(fdt, ""); if (ret < 0) { goto fail; } ret = fdt_end_node(fdt); if (ret < 0) { goto fail; } ret = fdt_finish(fdt); if (ret < 0) { goto fail; } ret = fdt_open_into(fdt, fdt, *sizep); if (ret) { error_report("Unable to copy device tree in memory"); exit(1); } return fdt; fail: error_report("%s Couldn't create dt: %s", __func__, fdt_strerror(ret)); exit(1); } void *load_device_tree(const char *filename_path, int *sizep) { int dt_size; int dt_file_load_size; int ret; void *fdt = NULL; *sizep = 0; dt_size = get_image_size(filename_path); if (dt_size < 0) { error_report("Unable to get size of device tree file '%s'", filename_path); goto fail; } if (dt_size > INT_MAX / 2 - 10000) { error_report("Device tree file '%s' is too large", filename_path); goto fail; } /* Expand to 2x size to give enough room for manipulation. */ dt_size += 10000; dt_size *= 2; /* First allocate space in qemu for device tree */ fdt = g_malloc0(dt_size); dt_file_load_size = load_image_size(filename_path, fdt, dt_size); if (dt_file_load_size < 0) { error_report("Unable to open device tree file '%s'", filename_path); goto fail; } ret = fdt_open_into(fdt, fdt, dt_size); if (ret) { error_report("Unable to copy device tree in memory"); goto fail; } /* Check sanity of device tree */ if (fdt_check_header(fdt)) { error_report("Device tree file loaded into memory is invalid: %s", filename_path); goto fail; } *sizep = dt_size; return fdt; fail: g_free(fdt); return NULL; } #ifdef CONFIG_LINUX #define SYSFS_DT_BASEDIR "/proc/device-tree" /** * read_fstree: this function is inspired from dtc read_fstree * @fdt: preallocated fdt blob buffer, to be populated * @dirname: directory to scan under SYSFS_DT_BASEDIR * the search is recursive and the tree is searched down to the * leaves (property files). * * the function asserts in case of error */ static void read_fstree(void *fdt, const char *dirname) { DIR *d; struct dirent *de; struct stat st; const char *root_dir = SYSFS_DT_BASEDIR; const char *parent_node; if (strstr(dirname, root_dir) != dirname) { error_report("%s: %s must be searched within %s", __func__, dirname, root_dir); exit(1); } parent_node = &dirname[strlen(SYSFS_DT_BASEDIR)]; d = opendir(dirname); if (!d) { error_report("%s cannot open %s", __func__, dirname); exit(1); } while ((de = readdir(d)) != NULL) { char *tmpnam; if (!g_strcmp0(de->d_name, ".") || !g_strcmp0(de->d_name, "..")) { continue; } tmpnam = g_strdup_printf("%s/%s", dirname, de->d_name); if (lstat(tmpnam, &st) < 0) { error_report("%s cannot lstat %s", __func__, tmpnam); exit(1); } if (S_ISREG(st.st_mode)) { gchar *val; gsize len; if (!g_file_get_contents(tmpnam, &val, &len, NULL)) { error_report("%s not able to extract info from %s", __func__, tmpnam); exit(1); } if (strlen(parent_node) > 0) { qemu_fdt_setprop(fdt, parent_node, de->d_name, val, len); } else { qemu_fdt_setprop(fdt, "/", de->d_name, val, len); } g_free(val); } else if (S_ISDIR(st.st_mode)) { char *node_name; node_name = g_strdup_printf("%s/%s", parent_node, de->d_name); qemu_fdt_add_subnode(fdt, node_name); g_free(node_name); read_fstree(fdt, tmpnam); } g_free(tmpnam); } closedir(d); } /* load_device_tree_from_sysfs: extract the dt blob from host sysfs */ void *load_device_tree_from_sysfs(void) { void *host_fdt; int host_fdt_size; host_fdt = create_device_tree(&host_fdt_size); read_fstree(host_fdt, SYSFS_DT_BASEDIR); if (fdt_check_header(host_fdt)) { error_report("%s host device tree extracted into memory is invalid", __func__); exit(1); } return host_fdt; } #endif /* CONFIG_LINUX */ static int findnode_nofail(void *fdt, const char *node_path) { int offset; offset = fdt_path_offset(fdt, node_path); if (offset < 0) { error_report("%s Couldn't find node %s: %s", __func__, node_path, fdt_strerror(offset)); exit(1); } return offset; } char **qemu_fdt_node_unit_path(void *fdt, const char *name, Error **errp) { char *prefix = g_strdup_printf("%s@", name); unsigned int path_len = 16, n = 0; GSList *path_list = NULL, *iter; const char *iter_name; int offset, len, ret; char **path_array; offset = fdt_next_node(fdt, -1, NULL); while (offset >= 0) { iter_name = fdt_get_name(fdt, offset, &len); if (!iter_name) { offset = len; break; } if (!strcmp(iter_name, name) || g_str_has_prefix(iter_name, prefix)) { char *path; path = g_malloc(path_len); while ((ret = fdt_get_path(fdt, offset, path, path_len)) == -FDT_ERR_NOSPACE) { path_len += 16; path = g_realloc(path, path_len); } path_list = g_slist_prepend(path_list, path); n++; } offset = fdt_next_node(fdt, offset, NULL); } g_free(prefix); if (offset < 0 && offset != -FDT_ERR_NOTFOUND) { error_setg(errp, "%s: abort parsing dt for %s node units: %s", __func__, name, fdt_strerror(offset)); for (iter = path_list; iter; iter = iter->next) { g_free(iter->data); } g_slist_free(path_list); return NULL; } path_array = g_new(char *, n + 1); path_array[n--] = NULL; for (iter = path_list; iter; iter = iter->next) { path_array[n--] = iter->data; } g_slist_free(path_list); return path_array; } char **qemu_fdt_node_path(void *fdt, const char *name, char *compat, Error **errp) { int offset, len, ret; const char *iter_name; unsigned int path_len = 16, n = 0; GSList *path_list = NULL, *iter; char **path_array; offset = fdt_node_offset_by_compatible(fdt, -1, compat); while (offset >= 0) { iter_name = fdt_get_name(fdt, offset, &len); if (!iter_name) { offset = len; break; } if (!strcmp(iter_name, name)) { char *path; path = g_malloc(path_len); while ((ret = fdt_get_path(fdt, offset, path, path_len)) == -FDT_ERR_NOSPACE) { path_len += 16; path = g_realloc(path, path_len); } path_list = g_slist_prepend(path_list, path); n++; } offset = fdt_node_offset_by_compatible(fdt, offset, compat); } if (offset < 0 && offset != -FDT_ERR_NOTFOUND) { error_setg(errp, "%s: abort parsing dt for %s/%s: %s", __func__, name, compat, fdt_strerror(offset)); for (iter = path_list; iter; iter = iter->next) { g_free(iter->data); } g_slist_free(path_list); return NULL; } path_array = g_new(char *, n + 1); path_array[n--] = NULL; for (iter = path_list; iter; iter = iter->next) { path_array[n--] = iter->data; } g_slist_free(path_list); return path_array; } int qemu_fdt_setprop(void *fdt, const char *node_path, const char *property, const void *val, int size) { int r; r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val, size); if (r < 0) { error_report("%s: Couldn't set %s/%s: %s", __func__, node_path, property, fdt_strerror(r)); exit(1); } return r; } int qemu_fdt_setprop_cell(void *fdt, const char *node_path, const char *property, uint32_t val) { int r; r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val); if (r < 0) { error_report("%s: Couldn't set %s/%s = %#08x: %s", __func__, node_path, property, val, fdt_strerror(r)); exit(1); } return r; } int qemu_fdt_setprop_u64(void *fdt, const char *node_path, const char *property, uint64_t val) { val = cpu_to_be64(val); return qemu_fdt_setprop(fdt, node_path, property, &val, sizeof(val)); } int qemu_fdt_setprop_string(void *fdt, const char *node_path, const char *property, const char *string) { int r; r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string); if (r < 0) { error_report("%s: Couldn't set %s/%s = %s: %s", __func__, node_path, property, string, fdt_strerror(r)); exit(1); } return r; } const void *qemu_fdt_getprop(void *fdt, const char *node_path, const char *property, int *lenp, Error **errp) { int len; const void *r; if (!lenp) { lenp = &len; } r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp); if (!r) { error_setg(errp, "%s: Couldn't get %s/%s: %s", __func__, node_path, property, fdt_strerror(*lenp)); } return r; } uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path, const char *property, int *lenp, Error **errp) { int len; const uint32_t *p; if (!lenp) { lenp = &len; } p = qemu_fdt_getprop(fdt, node_path, property, lenp, errp); if (!p) { return 0; } else if (*lenp != 4) { error_setg(errp, "%s: %s/%s not 4 bytes long (not a cell?)", __func__, node_path, property); *lenp = -EINVAL; return 0; } return be32_to_cpu(*p); } uint32_t qemu_fdt_get_phandle(void *fdt, const char *path) { uint32_t r; r = fdt_get_phandle(fdt, findnode_nofail(fdt, path)); if (r == 0) { error_report("%s: Couldn't get phandle for %s: %s", __func__, path, fdt_strerror(r)); exit(1); } return r; } int qemu_fdt_setprop_phandle(void *fdt, const char *node_path, const char *property, const char *target_node_path) { uint32_t phandle = qemu_fdt_get_phandle(fdt, target_node_path); return qemu_fdt_setprop_cell(fdt, node_path, property, phandle); } uint32_t qemu_fdt_alloc_phandle(void *fdt) { static int phandle = 0x0; /* * We need to find out if the user gave us special instruction at * which phandle id to start allocating phandles. */ if (!phandle) { phandle = machine_phandle_start(current_machine); } if (!phandle) { /* * None or invalid phandle given on the command line, so fall back to * default starting point. */ phandle = 0x8000; } return phandle++; } int qemu_fdt_nop_node(void *fdt, const char *node_path) { int r; r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path)); if (r < 0) { error_report("%s: Couldn't nop node %s: %s", __func__, node_path, fdt_strerror(r)); exit(1); } return r; } int qemu_fdt_add_subnode(void *fdt, const char *name) { char *dupname = g_strdup(name); char *basename = strrchr(dupname, '/'); int retval; int parent = 0; if (!basename) { g_free(dupname); return -1; } basename[0] = '\0'; basename++; if (dupname[0]) { parent = findnode_nofail(fdt, dupname); } retval = fdt_add_subnode(fdt, parent, basename); if (retval < 0) { error_report("FDT: Failed to create subnode %s: %s", name, fdt_strerror(retval)); exit(1); } g_free(dupname); return retval; } void qemu_fdt_dumpdtb(void *fdt, int size) { const char *dumpdtb = qemu_opt_get(qemu_get_machine_opts(), "dumpdtb"); if (dumpdtb) { /* Dump the dtb to a file and quit */ exit(g_file_set_contents(dumpdtb, fdt, size, NULL) ? 0 : 1); } } int qemu_fdt_setprop_sized_cells_from_array(void *fdt, const char *node_path, const char *property, int numvalues, uint64_t *values) { uint32_t *propcells; uint64_t value; int cellnum, vnum, ncells; uint32_t hival; int ret; propcells = g_new0(uint32_t, numvalues * 2); cellnum = 0; for (vnum = 0; vnum < numvalues; vnum++) { ncells = values[vnum * 2]; if (ncells != 1 && ncells != 2) { ret = -1; goto out; } value = values[vnum * 2 + 1]; hival = cpu_to_be32(value >> 32); if (ncells > 1) { propcells[cellnum++] = hival; } else if (hival != 0) { ret = -1; goto out; } propcells[cellnum++] = cpu_to_be32(value); } ret = qemu_fdt_setprop(fdt, node_path, property, propcells, cellnum * sizeof(uint32_t)); out: g_free(propcells); return ret; }