hwstub_shell: add support for call and jump

Change-Id: Ie09d0db21831b79255da858bada7382a08ff4eef
Reviewed-on: http://gerrit.rockbox.org/1052
Reviewed-by: Marcin Bukat <marcin.bukat@gmail.com>
Tested: Marcin Bukat <marcin.bukat@gmail.com>

utils/hwstub/tools/lua/hwlib.lua

@@ -0,0 +1,27 @@
+HWLIB = {}
+
+local h = HELP:create_topic("HWLIB")
+h:add("This table contains helper functions for use inside hwstub_shell")
+
+local hh = h:create_topic("load_blob")
+hh:add("load_blob(filename, address) -- this function loads raw binary blob from the file filename")
+hh:add("                                at specified address in memory. No cache coherency is")
+hh:add("                                guaranteed")
+
+hh = h:create_topic("printf")
+hh:add("printf(s,...) -- this function is simple wrapper around string.format to emulate")
+hh:add("                 C printf() function")
+
+function HWLIB.load_blob(filename, address)
+    local f = assert(io.open(filename, "rb"))
+    local bytes = f:read("*all")
+    for b in string.gmatch(bytes, ".") do
+        DEV.write8(address, string.byte(b))
+        address = address + 1
+    end
+    io.close(f)
+end
+
+function HWLIB.printf(s,...)
+    return io.write(s:format(...))
+end