[POWERPC] bootwrapper: Add a firmware-independent simpleboot target.

This target produces a flat binary rather than an ELF file,
fixes the entry point at the beginning of the image, and takes
a complete device tree with no fixups needed.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/arch/powerpc/boot/simpleboot.c b/arch/powerpc/boot/simpleboot.c
new file mode 100644
index 000000000000..86cd285bccc6
--- /dev/null
+++ b/arch/powerpc/boot/simpleboot.c
@@ -0,0 +1,84 @@
+/*
+ * The simple platform -- for booting when firmware doesn't supply a device
+ *                        tree or any platform configuration information.
+ *                        All data is extracted from an embedded device tree
+ *                        blob.
+ *
+ * Authors: Scott Wood <scottwood@freescale.com>
+ *          Grant Likely <grant.likely@secretlab.ca>
+ *
+ * Copyright (c) 2007 Freescale Semiconductor, Inc.
+ * Copyright (c) 2008 Secret Lab Technologies Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include "ops.h"
+#include "types.h"
+#include "io.h"
+#include "stdio.h"
+#include "libfdt/libfdt.h"
+
+BSS_STACK(4*1024);
+
+void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
+                   unsigned long r6, unsigned long r7)
+{
+        const u32 *na, *ns, *reg, *timebase;
+        u64 memsize64;
+        int node, size, i;
+
+        /* Make sure FDT blob is sane */
+        if (fdt_check_header(_dtb_start) != 0)
+                fatal("Invalid device tree blob\n");
+
+        /* Find the #address-cells and #size-cells properties */
+        node = fdt_path_offset(_dtb_start, "/");
+        if (node < 0)
+                fatal("Cannot find root node\n");
+        na = fdt_getprop(_dtb_start, node, "#address-cells", &size);
+        if (!na || (size != 4))
+                fatal("Cannot find #address-cells property");
+        ns = fdt_getprop(_dtb_start, node, "#size-cells", &size);
+        if (!ns || (size != 4))
+                fatal("Cannot find #size-cells property");
+
+        /* Find the memory range */
+        node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
+                                             "memory", sizeof("memory"));
+        if (node < 0)
+                fatal("Cannot find memory node\n");
+        reg = fdt_getprop(_dtb_start, node, "reg", &size);
+        if (size < (*na+*ns) * sizeof(u32))
+                fatal("cannot get memory range\n");
+
+        /* Only interested in memory based at 0 */
+        for (i = 0; i < *na; i++)
+                if (*reg++ != 0)
+                        fatal("Memory range is not based at address 0\n");
+
+        /* get the memsize and trucate it to under 4G on 32 bit machines */
+        memsize64 = 0;
+        for (i = 0; i < *ns; i++)
+                memsize64 = (memsize64 << 32) | *reg++;
+        if (sizeof(void *) == 4 && memsize64 >= 0x100000000ULL)
+                memsize64 = 0xffffffff;
+
+        /* finally, setup the timebase */
+        node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
+                                             "cpu", sizeof("cpu"));
+        if (!node)
+                fatal("Cannot find cpu node\n");
+        timebase = fdt_getprop(_dtb_start, node, "timebase-frequency", &size);
+        if (timebase && (size == 4))
+                timebase_period_ns = 1000000000 / *timebase;
+
+        /* Now we have the memory size; initialize the heap */
+        simple_alloc_init(_end, memsize64 - (unsigned long)_end, 32, 64);
+
+        /* prepare the device tree and find the console */
+        fdt_init(_dtb_start);
+        serial_console_init();
+}