[PATCH v1 2/4] kexec: Add common device tree routines
Geoff Levand
geoff at infradead.org
Tue Jul 19 16:28:13 PDT 2016
Common device tree routines that can be shared between all arches
that have device tree support.
Signed-off-by: Geoff Levand <geoff at infradead.org>
---
kexec/Makefile | 4 ++
kexec/dt-ops.c | 139 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
kexec/dt-ops.h | 13 ++++++
3 files changed, 156 insertions(+)
create mode 100644 kexec/dt-ops.c
create mode 100644 kexec/dt-ops.h
diff --git a/kexec/Makefile b/kexec/Makefile
index e2aee84..cc3f08b 100644
--- a/kexec/Makefile
+++ b/kexec/Makefile
@@ -73,6 +73,10 @@ dist += kexec/mem_regions.c kexec/mem_regions.h
$(ARCH)_MEM_REGIONS =
KEXEC_SRCS += $($(ARCH)_MEM_REGIONS)
+dist += kexec/dt-ops.c kexec/dt-ops.h
+$(ARCH)_DT_OPS =
+KEXEC_SRCS += $($(ARCH)_DT_OPS)
+
include $(srcdir)/kexec/arch/alpha/Makefile
include $(srcdir)/kexec/arch/arm/Makefile
include $(srcdir)/kexec/arch/i386/Makefile
diff --git a/kexec/dt-ops.c b/kexec/dt-ops.c
new file mode 100644
index 0000000..060776a
--- /dev/null
+++ b/kexec/dt-ops.c
@@ -0,0 +1,139 @@
+#include <assert.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <libfdt.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "kexec.h"
+#include "dt-ops.h"
+
+static const char n_chosen[] = "/chosen";
+
+static const char p_bootargs[] = "bootargs";
+static const char p_initrd_start[] = "linux,initrd-start";
+static const char p_initrd_end[] = "linux,initrd-end";
+
+int dtb_set_initrd(char **dtb, off_t *dtb_size, off_t start, off_t end)
+{
+ int result;
+ uint64_t value;
+
+ dbgprintf("%s: start %jd, end %jd, size %jd (%jd KiB)\n",
+ __func__, (intmax_t)start, (intmax_t)end,
+ (intmax_t)(end - start),
+ (intmax_t)(end - start) / 1024);
+
+ value = cpu_to_fdt64(start);
+
+ result = dtb_set_property(dtb, dtb_size, n_chosen, p_initrd_start,
+ &value, sizeof(value));
+
+ if (result)
+ return result;
+
+ value = cpu_to_fdt64(end);
+
+ result = dtb_set_property(dtb, dtb_size, n_chosen, p_initrd_end,
+ &value, sizeof(value));
+
+ if (result) {
+ dtb_delete_property(*dtb, n_chosen, p_initrd_start);
+ return result;
+ }
+
+ return 0;
+}
+
+int dtb_set_bootargs(char **dtb, off_t *dtb_size, const char *command_line)
+{
+ return dtb_set_property(dtb, dtb_size, n_chosen, p_bootargs,
+ command_line, strlen(command_line) + 1);
+}
+
+int dtb_set_property(char **dtb, off_t *dtb_size, const char *node,
+ const char *prop, const void *value, int value_len)
+{
+ int result;
+ int nodeoffset;
+ void *new_dtb;
+ int new_size;
+
+ value_len = FDT_TAGALIGN(value_len);
+
+ new_size = FDT_TAGALIGN(*dtb_size + fdt_node_len(node)
+ + fdt_prop_len(prop, value_len));
+
+ new_dtb = malloc(new_size);
+
+ if (!new_dtb) {
+ dbgprintf("%s: malloc failed\n", __func__);
+ return -ENOMEM;
+ }
+
+ result = fdt_open_into(*dtb, new_dtb, new_size);
+
+ if (result) {
+ dbgprintf("%s: fdt_open_into failed: %s\n", __func__,
+ fdt_strerror(result));
+ goto on_error;
+ }
+
+ nodeoffset = fdt_path_offset(new_dtb, node);
+
+ if (nodeoffset == -FDT_ERR_NOTFOUND) {
+ result = fdt_add_subnode(new_dtb, nodeoffset, node);
+
+ if (result) {
+ dbgprintf("%s: fdt_add_subnode failed: %s\n", __func__,
+ fdt_strerror(result));
+ goto on_error;
+ }
+ } else if (nodeoffset < 0) {
+ dbgprintf("%s: fdt_path_offset failed: %s\n", __func__,
+ fdt_strerror(nodeoffset));
+ goto on_error;
+ }
+
+ result = fdt_setprop(new_dtb, nodeoffset, prop, value, value_len);
+
+ if (result) {
+ dbgprintf("%s: fdt_setprop failed: %s\n", __func__,
+ fdt_strerror(result));
+ goto on_error;
+ }
+
+ /*
+ * Can't call free on dtb since dtb may have been mmaped by
+ * slurp_file().
+ */
+
+ *dtb = new_dtb;
+ *dtb_size = new_size;
+
+ return 0;
+
+on_error:
+ free(new_dtb);
+ return result;
+}
+
+int dtb_delete_property(char *dtb, const char *node, const char *prop)
+{
+ int result;
+ int nodeoffset = fdt_path_offset(dtb, node);
+
+ if (nodeoffset < 0) {
+ dbgprintf("%s: fdt_path_offset failed: %s\n", __func__,
+ fdt_strerror(nodeoffset));
+ return nodeoffset;
+ }
+
+ result = fdt_delprop(dtb, nodeoffset, prop);
+
+ if (result)
+ dbgprintf("%s: fdt_delprop failed: %s\n", __func__,
+ fdt_strerror(nodeoffset));
+
+ return result;
+}
diff --git a/kexec/dt-ops.h b/kexec/dt-ops.h
new file mode 100644
index 0000000..e70d15d
--- /dev/null
+++ b/kexec/dt-ops.h
@@ -0,0 +1,13 @@
+#if !defined(KEXEC_DT_OPS_H)
+#define KEXEC_DT_OPS_H
+
+#include <sys/types.h>
+
+int dtb_set_initrd(char **dtb, off_t *dtb_size, off_t start, off_t end);
+int dtb_set_bootargs(char **dtb, off_t *dtb_size, const char *command_line);
+int dtb_set_property(char **dtb, off_t *dtb_size, const char *node,
+ const char *prop, const void *value, int value_len);
+
+int dtb_delete_property(char *dtb, const char *node, const char *prop);
+
+#endif
--
2.5.0
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