tashaboot: arm64 bringup, semihosting payload loader

consoles on the pl011 the dtb points at, walks the memory node and
chosen, loads an arm64 kernel Image over semihosting and jumps to it
with the documented register state. string functions, printf and
libfdt are vendored from lk (lk2nd) and u-boot so the libc surface is
the one those projects already proved. built and booted on qemu virt,
payload exits clean through semihosting.

1 files changed, 101 insertions, 0 deletions

diff --git a/lib/libfdt/fdt_addresses.c b/lib/libfdt/fdt_addresses.c
new file mode 100644
index 0000000..c40ba09
--- /dev/null
+++ b/lib/libfdt/fdt_addresses.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Copyright (C) 2014 David Gibson <david@gibson.dropbear.id.au>
+ * Copyright (C) 2018 embedded brains GmbH
+ */
+#include "libfdt_env.h"
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "libfdt_internal.h"
+
+static int fdt_cells(const void *fdt, int nodeoffset, const char *name)
+{
+	const fdt32_t *c;
+	uint32_t val;
+	int len;
+
+	c = fdt_getprop(fdt, nodeoffset, name, &len);
+	if (!c)
+		return len;
+
+	if (len != sizeof(*c))
+		return -FDT_ERR_BADNCELLS;
+
+	val = fdt32_to_cpu(*c);
+	if (val > FDT_MAX_NCELLS)
+		return -FDT_ERR_BADNCELLS;
+
+	return (int)val;
+}
+
+int fdt_address_cells(const void *fdt, int nodeoffset)
+{
+	int val;
+
+	val = fdt_cells(fdt, nodeoffset, "#address-cells");
+	if (val == 0)
+		return -FDT_ERR_BADNCELLS;
+	if (val == -FDT_ERR_NOTFOUND)
+		return 2;
+	return val;
+}
+
+int fdt_size_cells(const void *fdt, int nodeoffset)
+{
+	int val;
+
+	val = fdt_cells(fdt, nodeoffset, "#size-cells");
+	if (val == -FDT_ERR_NOTFOUND)
+		return 1;
+	return val;
+}
+
+/* This function assumes that [address|size]_cells is 1 or 2 */
+int fdt_appendprop_addrrange(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, parent);
+	if (ret < 0)
+		return ret;
+	addr_cells = ret;
+
+	ret = fdt_size_cells(fdt, parent);
+	if (ret < 0)
+		return ret;
+	size_cells = ret;
+
+	/* check validity of address */
+	prop = data;
+	if (addr_cells == 1) {
+		if ((addr > UINT32_MAX) || (((uint64_t) UINT32_MAX + 1 - addr) < size))
+			return -FDT_ERR_BADVALUE;
+
+		fdt32_st(prop, (uint32_t)addr);
+	} else if (addr_cells == 2) {
+		fdt64_st(prop, addr);
+	} else {
+		return -FDT_ERR_BADNCELLS;
+	}
+
+	/* check validity of size */
+	prop += addr_cells * sizeof(fdt32_t);
+	if (size_cells == 1) {
+		if (size > UINT32_MAX)
+			return -FDT_ERR_BADVALUE;
+
+		fdt32_st(prop, (uint32_t)size);
+	} else if (size_cells == 2) {
+		fdt64_st(prop, size);
+	} else {
+		return -FDT_ERR_BADNCELLS;
+	}
+
+	return fdt_appendprop(fdt, nodeoffset, name, data,
+			      (addr_cells + size_cells) * sizeof(fdt32_t));
+}