linux-kernel - [PATCH 3/5] scripts/gdb: Add io resource readers

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Date:	Wed, 20 Jan 2016 11:15:48 +0000
From:	Kieran Bingham <kieran.bingham@...aro.org>
To:	jan.kiszka@...mens.com
Cc:	Kieran Bingham <kieran.bingham@...aro.org>,
	linux-kernel@...r.kernel.org, maxime.coquelin@...com,
	peter.griffin@...aro.org, lee.jones@...aro.org
Subject: [PATCH 3/5] scripts/gdb: Add io resource readers

Provide iomem_resource and ioports_resource printers and command hooks

Signed-off-by: Kieran Bingham <kieran.bingham@...aro.org>

---

These two readers are a useful extract of kernel information.
This shows the power of having these commands in gdb/scripts as you can
halt a kernel as it's booting and read these as the structures grow.

It should be useful in the event that a kernel is not booting, you
can identify what memory resources have been registered



 scripts/gdb/linux/proc.py | 57 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/scripts/gdb/linux/proc.py b/scripts/gdb/linux/proc.py
index 6e6709c1830c..d855b2fd9a06 100644
--- a/scripts/gdb/linux/proc.py
+++ b/scripts/gdb/linux/proc.py
@@ -39,3 +39,60 @@ class LxVersion(gdb.Command):
         gdb.write(gdb.parse_and_eval("linux_banner").string())
 
 LxVersion()
+
+
+# Resource Structure Printers
+#  /proc/iomem
+#  /proc/ioports
+
+def get_resources(resource, depth):
+    while resource:
+        yield resource, depth
+
+        child = resource['child']
+        if child:
+            for res, deep in get_resources(child, depth + 1):
+                yield res, deep
+
+        resource = resource['sibling']
+
+
+def show_lx_resources(resource_str):
+        resource = gdb.parse_and_eval(resource_str)
+        width = 4 if resource['end'] < 0x10000 else 8
+        # Iterate straight to the first child
+        for res, depth in get_resources(resource['child'], 0):
+            start = int(res['start'])
+            end = int(res['end'])
+            gdb.write(" " * depth * 2 +
+                      "{0:0{1}x}-".format(start, width) +
+                      "{0:0{1}x} : ".format(end, width) +
+                      res['name'].string() + "\n")
+
+
+class LxIOMem(gdb.Command):
+    """Identify the IO memory resource locations defined by the kernel
+
+Equivalent to cat /proc/iomem on a running target"""
+
+    def __init__(self):
+        super(LxIOMem, self).__init__("lx-iomem", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        return show_lx_resources("iomem_resource")
+
+LxIOMem()
+
+
+class LxIOPorts(gdb.Command):
+    """Identify the IO port resource locations defined by the kernel
+
+Equivalent to cat /proc/ioports on a running target"""
+
+    def __init__(self):
+        super(LxIOPorts, self).__init__("lx-ioports", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        return show_lx_resources("ioport_resource")
+
+LxIOPorts()
-- 
2.5.0