sandbox: Improve debugging in initcall_run_list()

At present if one of the initcalls fails on sandbox the address printing
is not help, e.g.:

  initcall sequence 0000557678967c80 failed at call 00005576709dfe1f (err=-96)

This is because U-Boot gets relocated high into memory and the relocation
offset (gd->reloc_off) does not work correctly for sandbox.

Add support for finding the base address of the text region (at least on
Linux) and use that to set the relocation offset. This makes the output
better:

  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)

Signed-off-by: Simon Glass <sjg@chromium.org>

2 files changed, 17 insertions, 2 deletions

diff --git a/include/initcall.h b/include/initcall.h
index 3ac01aa2cd..a38c83efa4 100644
--- a/include/initcall.h
+++ b/include/initcall.h
@@ -22,13 +22,17 @@ static inline int initcall_run_list(const init_fnc_t init_sequence[])
 		unsigned long reloc_ofs = 0;
 		int ret;
 
-		if (gd->flags & GD_FLG_RELOC)
+		/*
+		 * Sandbox is relocated by the OS, so symbols always appear at
+		 * the relocated address.
+		 */
+		if (IS_ENABLED(CONFIG_SANDBOX) || (gd->flags & GD_FLG_RELOC))
 			reloc_ofs = gd->reloc_off;
 #ifdef CONFIG_EFI_APP
 		reloc_ofs = (unsigned long)image_base;
 #endif
 		debug("initcall: %p", (char *)*init_fnc_ptr - reloc_ofs);
-		if (gd->flags & GD_FLG_RELOC)
+		if (reloc_ofs)
 			debug(" (relocated to %p)\n", (char *)*init_fnc_ptr);
 		else
 			debug("\n");
diff --git a/include/os.h b/include/os.h
index 6f33b08cf0..7a4f78b9b1 100644
--- a/include/os.h
+++ b/include/os.h
@@ -364,4 +364,15 @@ int os_write_file(const char *name, const void *buf, int size);
  */
 int os_read_file(const char *name, void **bufp, int *sizep);
 
+/*
+ * os_find_text_base() - Find the text section in this running process
+ *
+ * This tries to find the address of the text section in this running process.
+ * It can be useful to map the address of functions to the address listed in
+ * the u-boot.map file.
+ *
+ * @return address if found, else NULL
+ */
+void *os_find_text_base(void);
+
 #endif