From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33400) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZzR2R-0003J4-Fr for qemu-devel@nongnu.org; Thu, 19 Nov 2015 10:22:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZzR2P-0000hh-TN for qemu-devel@nongnu.org; Thu, 19 Nov 2015 10:22:19 -0500 Received: from mail-wm0-x232.google.com ([2a00:1450:400c:c09::232]:38565) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZzR2P-0000hY-N9 for qemu-devel@nongnu.org; Thu, 19 Nov 2015 10:22:17 -0500 Received: by wmec201 with SMTP id c201so122527910wme.1 for ; Thu, 19 Nov 2015 07:22:17 -0800 (PST) From: Eric Auger Date: Thu, 19 Nov 2015 15:22:04 +0000 Message-Id: <1447946528-1533-3-git-send-email-eric.auger@linaro.org> In-Reply-To: <1447946528-1533-1-git-send-email-eric.auger@linaro.org> References: <1447946528-1533-1-git-send-email-eric.auger@linaro.org> Subject: [Qemu-devel] [RESEND 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, qemu-arm@nongnu.org, alex.williamson@redhat.com, peter.maydell@linaro.org 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); -- 1.8.3.2