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[80.11.198.90]) by smtp.gmail.com with ESMTPSA id df10sm81858826wjb.44.2016.01.06.07.13.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 06 Jan 2016 07:13:29 -0800 (PST) From: Eric Auger To: eric.auger@st.com, eric.auger@linaro.org, qemu-devel@nongnu.org, qemu-arm@nongnu.org, peter.maydell@linaro.org, david@gibson.dropbear.id.au, alex.williamson@redhat.com Cc: alex.bennee@linaro.org, thuth@redhat.com, crosthwaitepeter@gmail.com, patches@linaro.org, christoffer.dall@linaro.org, pbonzini@redhat.com, b.reynal@virtualopensystems.com, suravee.suthikulpanit@amd.com, thomas.lendacky@amd.com Subject: [PATCH v2 2/7] device_tree: introduce load_device_tree_from_sysfs Date: Wed, 6 Jan 2016 15:13:20 +0000 Message-Id: <1452093205-30167-3-git-send-email-eric.auger@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1452093205-30167-1-git-send-email-eric.auger@linaro.org> References: <1452093205-30167-1-git-send-email-eric.auger@linaro.org> This function returns the host device tree blob from sysfs (/proc/device-tree). It uses a recursive function inspired from dtc read_fstree. Signed-off-by: Eric Auger --- v1 -> v2: - do not implement/expose read_fstree and load_device_tree_from_sysfs if CONFIG_LINUX is not defined (lstat is not implemeted in mingw) - correct indentation in read_fstree - use /proc/device-tree symlink instead of /sys/firmware/devicetree/base path (kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-ofw) - use g_file_get_contents in read_fstree - introduce SYSFS_DT_BASEDIR macro and use strlen - exit on error in load_device_tree_from_sysfs - user error_setg RFC -> v1: - remove runtime dependency on dtc binary and introduce read_fstree --- device_tree.c | 100 +++++++++++++++++++++++++++++++++++++++++++ include/sysemu/device_tree.h | 3 ++ 2 files changed, 103 insertions(+) -- 1.9.1 diff --git a/device_tree.c b/device_tree.c index a9f5f8e..b262c2d 100644 --- a/device_tree.c +++ b/device_tree.c @@ -17,6 +17,9 @@ #include #include #include +#ifdef CONFIG_LINUX +#include +#endif #include "qemu-common.h" #include "qemu/error-report.h" @@ -117,6 +120,103 @@ 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 + * leafs (property files). + * + * the function self-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; + 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 = (char *)&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_strjoin("/", dirname, de->d_name, NULL); + + 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 359e143..fdf25a4 100644 --- a/include/sysemu/device_tree.h +++ b/include/sysemu/device_tree.h @@ -16,6 +16,9 @@ void *create_device_tree(int *sizep); void *load_device_tree(const char *filename_path, int *sizep); +#ifdef CONFIG_LINUX +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);