Add two fake properties ("fdtbootcpu" and "fdtmemreserv") to the device

tree's /chosen node to provide out-of-band header fields of the FDT. This
emulation is not perfect without corresponding changes to ofw_fdt_nextprop(),
but is enough to enable lookup by memory-map-parsing code.

MFC after:	1 week

1 files changed, 20 insertions, 0 deletions

diff --git a/sys/dev/ofw/ofw_fdt.c b/sys/dev/ofw/ofw_fdt.c
index f4072a3..01f82c4 100644
--- a/sys/dev/ofw/ofw_fdt.c
+++ b/sys/dev/ofw/ofw_fdt.c
@@ -231,6 +231,13 @@ ofw_fdt_getproplen(ofw_t ofw, phandle_t package, const char *propname)
 		return (len + 1);
 	}
 
+	if (prop == NULL && offset == fdt_path_offset(fdtp, "/chosen")) {
+		if (strcmp(propname, "fdtbootcpu") == 0)
+			return (sizeof(cell_t));
+		if (strcmp(propname, "fdtmemreserv") == 0)
+			return (sizeof(uint64_t)*2*fdt_num_mem_rsv(fdtp));
+	}
+
 	return (len);
 }
 
@@ -242,6 +249,7 @@ ofw_fdt_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
 	const void *prop;
 	const char *name;
 	int len, offset;
+	uint32_t cpuid;
 
 	offset = fdt_phandle_offset(package);
 	if (offset < 0)
@@ -258,6 +266,18 @@ ofw_fdt_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
 		return (len + 1);
 	}
 
+	if (prop == NULL && offset == fdt_path_offset(fdtp, "/chosen")) {
+		if (strcmp(propname, "fdtbootcpu") == 0) {
+			cpuid = cpu_to_fdt32(fdt_boot_cpuid_phys(fdtp));
+			len = sizeof(cpuid);
+			prop = &cpuid;
+		}
+		if (strcmp(propname, "fdtmemreserv") == 0) {
+			prop = (char *)fdtp + fdt_off_mem_rsvmap(fdtp);
+			len = sizeof(uint64_t)*2*fdt_num_mem_rsv(fdtp);
+		}
+	}
+
 	if (prop == NULL)
 		return (-1);