diff options
| -rw-r--r-- | device_tree.c | 100 | ||||
| -rw-r--r-- | include/sysemu/device_tree.h | 8 |
2 files changed, 108 insertions, 0 deletions
diff --git a/device_tree.c b/device_tree.c index b1ad836073..9e77c6990c 100644 --- a/device_tree.c +++ b/device_tree.c @@ -13,6 +13,10 @@ #include "qemu/osdep.h" +#ifdef CONFIG_LINUX +#include <dirent.h> +#endif + #include "qemu-common.h" #include "qemu/error-report.h" #include "sysemu/device_tree.h" @@ -112,6 +116,102 @@ fail: 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_setg(&error_fatal, "%s: %s must be searched within %s", + __func__, dirname, root_dir); + } + parent_node = &dirname[strlen(SYSFS_DT_BASEDIR)]; + + d = opendir(dirname); + if (!d) { + error_setg(&error_fatal, "%s cannot open %s", __func__, dirname); + } + + 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_setg(&error_fatal, "%s cannot lstat %s", __func__, tmpnam); + } + + if (S_ISREG(st.st_mode)) { + gchar *val; + gsize len; + + if (!g_file_get_contents(tmpnam, &val, &len, NULL)) { + error_setg(&error_fatal, "%s not able to extract info from %s", + __func__, tmpnam); + } + + 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_setg(&error_fatal, + "%s host device tree extracted into memory is invalid", + __func__); + } + return host_fdt; +} + +#endif /* CONFIG_LINUX */ + static int findnode_nofail(void *fdt, const char *node_path) { int offset; diff --git a/include/sysemu/device_tree.h b/include/sysemu/device_tree.h index 359e14304f..62093bad7c 100644 --- a/include/sysemu/device_tree.h +++ b/include/sysemu/device_tree.h @@ -16,6 +16,14 @@ void *create_device_tree(int *sizep); void *load_device_tree(const char *filename_path, int *sizep); +#ifdef CONFIG_LINUX +/** + * load_device_tree_from_sysfs: reads the device tree information in the + * /proc/device-tree directory and return the corresponding binary blob + * buffer pointer. Asserts in case of error. + */ +void *load_device_tree_from_sysfs(void); +#endif int qemu_fdt_setprop(void *fdt, const char *node_path, const char *property, const void *val, int size); |