mgtool: Add support for setting fixed ROM address into image header

The commit adds support for IMAGE_F_ROM_FIXED flag that allows setting
information on image base address into image_header.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>
Signed-off-by: David Brown <david.brown@linaro.org>

Author: de-nordic

scripts/imgtool/image.py

@@ -49,9 +49,10 @@
 # Image header flags.
 IMAGE_F = {
         'PIC':                   0x0000001,
+        'ENCRYPTED':             0x0000004,
         'NON_BOOTABLE':          0x0000010,
         'RAM_LOAD':              0x0000020,
-        'ENCRYPTED':             0x0000004,
+        'ROM_FIXED':             0x0000100,
 }
 
 TLV_VALUES = {
@@ -130,7 +131,12 @@ def __init__(self, version=None, header_size=IMAGE_HEADER_SIZE,
                  pad_header=False, pad=False, confirm=False, align=1,
                  slot_size=0, max_sectors=DEFAULT_MAX_SECTORS,
                  overwrite_only=False, endian="little", load_addr=0,
-                 erased_val=None, save_enctlv=False, security_counter=None):
+                 rom_fixed=None, erased_val=None, save_enctlv=False,
+                 security_counter=None):
+
+        if load_addr and rom_fixed:
+            raise click.UsageError("Can not set rom_fixed and load_addr at the same time")
+
         self.version = version or versmod.decode_version("0")
         self.header_size = header_size
         self.pad_header = pad_header
@@ -143,6 +149,7 @@ def __init__(self, version=None, header_size=IMAGE_HEADER_SIZE,
         self.endian = endian
         self.base_addr = None
         self.load_addr = 0 if load_addr is None else load_addr
+        self.rom_fixed = rom_fixed
         self.erased_val = 0xff if erased_val is None else int(erased_val, 0)
         self.payload = []
         self.enckey = None
@@ -459,6 +466,8 @@ def add_header(self, enckey, protected_tlv_size):
             # Indicates that this image should be loaded into RAM
             # instead of run directly from flash.
             flags |= IMAGE_F['RAM_LOAD']
+        if self.rom_fixed:
+            flags |= IMAGE_F['ROM_FIXED']
 
         e = STRUCT_ENDIAN_DICT[self.endian]
         fmt = (e +
@@ -475,7 +484,7 @@ def add_header(self, enckey, protected_tlv_size):
         assert struct.calcsize(fmt) == IMAGE_HEADER_SIZE
         header = struct.pack(fmt,
                 IMAGE_MAGIC,
-                self.load_addr,
+                self.rom_fixed or self.load_addr,
                 self.header_size,
                 protected_tlv_size,  # TLV Info header + Protected TLVs
                 len(self.payload) - self.header_size,  # ImageSz

scripts/imgtool/main.py

@@ -239,6 +239,8 @@ def convert(self, value, param, ctx):
               help='Adjust address in hex output file.')
 @click.option('-L', '--load-addr', type=BasedIntParamType(), required=False,
               help='Load address for image when it should run from RAM.')
+@click.option('-F', '--rom-fixed', type=BasedIntParamType(), required=False,
+              help='Set flash address the image is built for.')
 @click.option('--save-enctlv', default=False, is_flag=True,
               help='When upgrading, save encrypted key TLVs instead of plain '
                    'keys. Enable when BOOT_SWAP_SAVE_ENCTLV config option '
@@ -292,7 +294,8 @@ def convert(self, value, param, ctx):
 def sign(key, public_key_format, align, version, pad_sig, header_size,
          pad_header, slot_size, pad, confirm, max_sectors, overwrite_only,
          endian, encrypt, infile, outfile, dependencies, load_addr, hex_addr,
-         erased_val, save_enctlv, security_counter, boot_record, custom_tlv):
+         erased_val, save_enctlv, security_counter, boot_record, custom_tlv,
+         rom_fixed):
 
     if confirm:
         # Confirmed but non-padded images don't make much sense, because
@@ -302,8 +305,8 @@ def sign(key, public_key_format, align, version, pad_sig, header_size,
                       pad_header=pad_header, pad=pad, confirm=confirm,
                       align=int(align), slot_size=slot_size,
                       max_sectors=max_sectors, overwrite_only=overwrite_only,
-                      endian=endian, load_addr=load_addr, erased_val=erased_val,
-                      save_enctlv=save_enctlv,
+                      endian=endian, load_addr=load_addr, rom_fixed=rom_fixed,
+                      erased_val=erased_val, save_enctlv=save_enctlv,
                       security_counter=security_counter)
     img.load(infile)
     key = load_key(key) if key else None