sandbox: Move pre-console buffer out of the way of tracing

[pandora-u-boot.git] / board / sandbox / README.sandbox

diff --git a/board/sandbox/README.sandbox b/board/sandbox/README.sandbox
index a28fc9f..48c1e2b 100644 (file)
--- a/board/sandbox/README.sandbox
+++ b/board/sandbox/README.sandbox
@@ -247,25 +247,28 @@ sudo /path/to/u-boot -D
 DHCP
 ....
 
-set autoload no
-set ethact eth1
+setenv autoload no
+setenv ethrotate no
+setenv ethact eth1
 dhcp
 
 PING
 ....
 
-set autoload no
-set ethact eth1
+setenv autoload no
+setenv ethrotate no
+setenv ethact eth1
 dhcp
 ping $gatewayip
 
 TFTP
 ....
 
-set autoload no
-set ethact eth1
+setenv autoload no
+setenv ethrotate no
+setenv ethact eth1
 dhcp
-set serverip WWW.XXX.YYY.ZZZ
+setenv serverip WWW.XXX.YYY.ZZZ
 tftpboot u-boot.bin
 
 The bridge also supports (to a lesser extent) the localhost interface, 'lo'.
@@ -287,7 +290,8 @@ operation being tested on the lo interface.
 TFTP
 ....
 
-set ethact eth5
+setenv ethrotate no
+setenv ethact eth5
 tftpboot u-boot.bin
 
 
@@ -388,6 +392,49 @@ state_setprop() which does this automatically and avoids running out of
 space. See existing code for examples.
 
 
+Debugging the init sequence
+---------------------------
+
+If you get a failure in the initcall sequence, like this:
+
+   initcall sequence 0000560775957c80 failed at call 0000000000048134 (err=-96)
+
+Then you use can use grep to see which init call failed, e.g.:
+
+   $ grep 0000000000048134 u-boot.map
+   stdio_add_devices
+
+Of course another option is to run it with a debugger such as gdb:
+
+   $ gdb u-boot
+   ...
+   (gdb) br initcall.h:41
+   Breakpoint 1 at 0x4db9d: initcall.h:41. (2 locations)
+
+Note that two locations are reported, since this function is used in both
+board_init_f() and board_init_r().
+
+   (gdb) r
+   Starting program: /tmp/b/sandbox/u-boot
+   [Thread debugging using libthread_db enabled]
+   Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
+
+   U-Boot 2018.09-00264-ge0c2ba9814-dirty (Sep 22 2018 - 12:21:46 -0600)
+
+   DRAM:  128 MiB
+   MMC:
+
+   Breakpoint 1, initcall_run_list (init_sequence=0x5555559619e0 <init_sequence_f>)
+       at /scratch/sglass/cosarm/src/third_party/u-boot/files/include/initcall.h:41
+   41                              printf("initcall sequence %p failed at call %p (err=%d)\n",
+   (gdb) print *init_fnc_ptr
+   $1 = (const init_fnc_t) 0x55555559c114 <stdio_add_devices>
+   (gdb)
+
+
+This approach can be used on normal boards as well as sandbox.
+
+
 Testing
 -------
 
@@ -418,7 +465,22 @@ coverage in U-Boot is limited, as we need to work to improve it.
 Note that many of these tests are implemented as commands which you can
 run natively on your board if desired (and enabled).
 
-It would be useful to have a central script to run all of these.
+To run all tests use "make check".
+
+
+Memory Map
+----------
+
+Sandbox has its own emulated memory starting at 0. Here are some of the things
+that are mapped into that memory:
+
+      0   CONFIG_SYS_FDT_LOAD_ADDR   Device tree
+   e000   CONFIG_BLOBLIST_ADDR       Blob list
+  10000   CONFIG_MALLOC_F_ADDR       Early memory allocation
+  f0000   CONFIG_PRE_CON_BUF_ADDR    Pre-console buffer
+ 100000   CONFIG_TRACE_EARLY_ADDR    Early trace buffer (if enabled)
+=
+
 
 --
 Simon Glass <sjg@chromium.org>