1 files changed, 134 insertions, 0 deletions
diff --git a/libfdt/libfdt_address.c b/libfdt/libfdt_address.c
new file mode 100644
index 0000000..7d40178
--- /dev/null
+++ b/libfdt/libfdt_address.c
@@ -0,0 +1,134 @@
+/* -------------------------------------------
+
+    Copyright (C) 2024, Amlal EL Mahrouss, all rights reserved.
+
+------------------------------------------- */
+
+#include <libfdt/libfdt_env.h>
+
+extern fdt32_t* fdt_getprop(const void* fdt, int nodeoffset, const char* name, int* len);
+extern fdt32_t* fdt_append_prop(const void* fdt, int nodeoffset, const char* name, uint8_t* data, int32_t len);
+
+#ifndef FDT_MAX_NCELLS
+#define FDT_MAX_NCELLS (4)
+#endif
+
+#ifndef FDT_BAD_NCELLS
+#define FDT_BAD_NCELLS (14)
+#endif
+
+#ifndef FDT_NOT_FOUND
+#define FDT_NOT_FOUND (1)
+#endif
+
+#ifndef FDT_BAD_VALUE
+#define FDT_BAD_VALUE (15)
+#endif
+
+static int fdt_cells(const void* fdt, int nodeoffset, const char* name)
+{
+	const fdt32_t* c   = null;
+	uint32_t	   val = 0;
+	int			   len = 0;
+
+	c = fdt_getprop(fdt, nodeoffset, name, &len);
+	if (c == null)
+		return len;
+
+	if (len != sizeof(*c))
+		return len;
+
+	val = fdt32_to_cpu(*c);
+	if (val > FDT_MAX_NCELLS)
+		return -FDT_BAD_NCELLS;
+
+	return (int)val;
+}
+
+int fdt_address_cells(const void* fdt, int nodeoffset)
+{
+	int val = 0;
+	val		= fdt_cells(fdt, nodeoffset, "#address-cells");
+	if (val == 0)
+		return -FDT_BAD_NCELLS;
+
+	if (val == -FDT_NOT_FOUND)
+		return 2;
+
+	return (int)val;
+}
+
+int fdt_size_cells(const void* fdt, int nodeoffset)
+{
+	int val = 0;
+	val		= fdt_cells(fdt, nodeoffset, "#size-cells");
+
+	if (val == -FDT_NOT_FOUND)
+		return 2;
+
+	return (int)val;
+}
+
+int fdt_append_prop_addr_range(void* fdt, int parent, int nodeoffset, const char* name, uint64_t addr, uint64_t size)
+{
+	int		addr_cells, size_cells, ret;
+	uint8_t data[sizeof(fdt64_t) * 2], *prop;
+
+	ret = fdt_address_cells(fdt, nodeoffset);
+	if (ret < 0)
+		return ret;
+
+	addr_cells = ret;
+
+	ret = fdt_size_cells(fdt, nodeoffset);
+	if (ret < 0)
+		return ret;
+
+	size_cells = ret;
+
+	// check address validity
+	prop = data;
+	if (addr_cells == 1)
+	{
+		// seems to do a check according to two parameters.
+		// addr > __UINT32_MAX__ detects any out of range addresses?
+		// ((__UINT32_MAX__ + 1 - addr) < size check if it's lower than it's size
+
+		if ((addr > __UINT32_MAX__) || ((__UINT32_MAX__ + 1 - addr) < size))
+			return -FDT_BAD_VALUE;
+
+		// finally set the flat device tree.
+		fdt32_st(prop, (uint32_t)addr);
+	}
+	else if (addr_cells == 2)
+	{
+		// no need to check, apparently.
+		fdt64_st(prop, addr);
+	}
+	else
+	{
+		return -FDT_BAD_NCELLS;
+	}
+
+	// access size
+	prop += addr_cells * sizeof(fdt32_t);
+
+	if (size_cells == 1)
+	{
+		if (size > __UINT32_MAX__)
+			return -FDT_BAD_VALUE;
+
+		fdt32_st(prop, (uint32_t)size);
+	}
+	else if (size_cells == 2)
+	{
+		fdt64_st(prop, size);
+	}
+	else
+	{
+		return -FDT_BAD_NCELLS;
+	}
+
+	return fdt_append_prop(fdt, nodeoffset, name, data,
+						   (addr_cells + size_cells) * sizeof(fdt32_t));
+}