From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33689) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZlgHS-0007sv-Py for qemu-devel@nongnu.org; Mon, 12 Oct 2015 12:48:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZlgHP-0003IO-FL for qemu-devel@nongnu.org; Mon, 12 Oct 2015 12:48:58 -0400 Received: from mail-wi0-f180.google.com ([209.85.212.180]:33337) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZlgHP-0003IH-Ab for qemu-devel@nongnu.org; Mon, 12 Oct 2015 12:48:55 -0400 Received: by wicge5 with SMTP id ge5so25241862wic.0 for ; Mon, 12 Oct 2015 09:48:54 -0700 (PDT) From: Eric Auger Date: Mon, 12 Oct 2015 16:48:39 +0000 Message-Id: <1444668523-2252-3-git-send-email-eric.auger@linaro.org> In-Reply-To: <1444668523-2252-1-git-send-email-eric.auger@linaro.org> References: <1444668523-2252-1-git-send-email-eric.auger@linaro.org> Subject: [Qemu-devel] [RFC 2/6] device_tree: introduce load_device_tree_from_sysfs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: eric.auger@st.com, eric.auger@linaro.org, qemu-devel@nongnu.org, alex.williamson@redhat.com Cc: thomas.lendacky@amd.com, b.reynal@virtualopensystems.com, patches@linaro.org, suravee.suthikulpanit@amd.com, pbonzini@redhat.com, christoffer.dall@linaro.org This function returns the host device tree blob from sysfs (/sys/firmware/devicetree/base). This has a runtime dependency on the dtc binary. This functionality is useful for platform device passthrough where the host device tree needs to be parsed to feed information into the guest device tree. Signed-off-by: Eric Auger --- device_tree.c | 40 ++++++++++++++++++++++++++++++++++++++++ include/sysemu/device_tree.h | 1 + 2 files changed, 41 insertions(+) diff --git a/device_tree.c b/device_tree.c index a9f5f8e..58a5329 100644 --- a/device_tree.c +++ b/device_tree.c @@ -117,6 +117,46 @@ fail: return NULL; } +/** + * load_device_tree_from_sysfs + * + * extract the dt blob from host sysfs + * this has a runtime dependency on the dtc binary + */ +void *load_device_tree_from_sysfs(void) +{ + char cmd[] = "dtc -I fs -O dtb /sys/firmware/devicetree/base"; + FILE *pipe; + void *fdt; + int ret, actual_dt_size; + + pipe = popen(cmd, "r"); + if (!pipe) { + error_report("%s: Error when executing dtc", __func__); + return NULL; + } + fdt = g_malloc0(FDT_MAX_SIZE); + actual_dt_size = fread(fdt, 1, FDT_MAX_SIZE, pipe); + pclose(pipe); + + if (actual_dt_size == 0) { + error_report("%s: could not copy host device tree in memory: %m", + __func__); + goto fail; + } + ret = fdt_check_header(fdt); + if (ret) { + error_report("%s: Host dt file loaded into memory is invalid: %s", + __func__, fdt_strerror(ret)); + goto fail; + } + return fdt; + +fail: + g_free(fdt); + return NULL; +} + 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..307e53d 100644 --- a/include/sysemu/device_tree.h +++ b/include/sysemu/device_tree.h @@ -16,6 +16,7 @@ void *create_device_tree(int *sizep); void *load_device_tree(const char *filename_path, int *sizep); +void *load_device_tree_from_sysfs(void); int qemu_fdt_setprop(void *fdt, const char *node_path, const char *property, const void *val, int size); -- 1.9.1