modmachine: Implement physical memory access using /dev/mem (Linux, etc).

This requires root access. And on recent Linux kernels, with
CONFIG_STRICT_DEVMEM option enabled, only address ranges listed in
/proc/iomem can be accessed. The above compiled-time option can be
however overriden with boot-time option "iomem=relaxed".

This also removed separate read/write paths - there unlikely would
be a case when they're different.

4 files changed, 17 insertions, 17 deletions

diff --git a/tests/extmod/machine1.py b/tests/extmod/machine1.py
index e7fd40d4d..af4dacd03 100644
--- a/tests/extmod/machine1.py
+++ b/tests/extmod/machine1.py
@@ -7,22 +7,8 @@ except ImportError:
     import sys
     sys.exit()
 
-import uctypes
-
 print(machine.mem8)
 
-buf = bytearray(8)
-addr = uctypes.addressof(buf)
-
-machine.mem8[addr] = 123
-print(machine.mem8[addr])
-
-machine.mem16[addr] = 12345
-print(machine.mem16[addr])
-
-machine.mem32[addr] = 123456789
-print(machine.mem32[addr])
-
 try:
     machine.mem16[1]
 except ValueError:
diff --git a/tests/extmod/machine1.py.exp b/tests/extmod/machine1.py.exp
index e46afc752..bb421ea5c 100644
--- a/tests/extmod/machine1.py.exp
+++ b/tests/extmod/machine1.py.exp
@@ -1,7 +1,4 @@
 <8-bit memory>
-123
-12345
-123456789
 ValueError
 ValueError
 TypeError
diff --git a/tests/extmod/machine_mem.py b/tests/extmod/machine_mem.py
new file mode 100644
index 000000000..7d8a9ac01
--- /dev/null
+++ b/tests/extmod/machine_mem.py
@@ -0,0 +1,16 @@
+# This test requires root privilege, so is usually skipped
+# It also assumes x86 legacy hardware (with Video BIOS present).
+
+try:
+    import machine
+except ImportError:
+    print("SKIP")
+    import sys
+    sys.exit()
+
+try:
+    print(hex(machine.mem16[0xc0000]))
+except OSError:
+    print("SKIP")
+    import sys
+    sys.exit()
diff --git a/tests/extmod/machine_mem.py.exp b/tests/extmod/machine_mem.py.exp
new file mode 100644
index 000000000..371f8fa44
--- /dev/null
+++ b/tests/extmod/machine_mem.py.exp
@@ -0,0 +1 @@
+0xaa55