[U-Boot] [TEST] arm:board_init_f(): mirror BSS and check after each init_fnc()

Andreas Bießmann
2010-12-01T08:10:50Z

This is only a patch to test if BSS was accessed in any function in init
function array!

DO NOT APPLY TO MAINLINE!

To run the test adopt the bss_mirror value to point somwhere in RAM with
sufficient space!

A step by step guide is like this:
* apply the patch
* adopt bss_mirror in arch/arm/lib/board.c:board_init_f()
* build and run like always
* search for something like: 'BSS got corrupted after init_fnc @ 0x20100478'
after banner
* use objdump to search the symbol
---8<---
arm-unknown-linux-gnueabi-objdump -S ../build_uboot-at91rm9200ek/u-boot | grep 20100478
20100478 <timer_init>:
20100478: e59f3064 ldr r3, [pc, #100] ; 201004e4 <timer_init+0x6c>
--->8---

Signed-off-by: Andreas Bie?mann <andreas.devel@googlemail.com>
---
arch/arm/lib/board.c | 18 ++++++++++++++++++
1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
index 1fd5f83..890e6f1 100644
--- a/arch/arm/lib/board.c
+++ b/arch/arm/lib/board.c
@@ -274,6 +274,10 @@ void board_init_f (ulong bootflag)
init_fnc_t **init_fnc_ptr;
gd_t *id;
ulong addr, addr_sp;
+ uint32_t *bss_mirror;
+ uint32_t *bss_start;
+ size_t bss_length;
+ init_fnc_t *break_bss = NULL;

/* Pointer is writable since we allocated a register for it */
gd = (gd_t *) (CONFIG_SYS_INIT_SP_ADDR);
@@ -284,12 +288,26 @@ void board_init_f (ulong bootflag)

gd->mon_len = _bss_end_ofs;

+ /* take a location in SDRAM which might be free */
+ bss_mirror = (uint32_t*)(CONFIG_SYS_SDRAM_BASE + 0x600000);
+ bss_start = (uint32_t*)(_bss_start_ofs + _TEXT_BASE);
+ bss_length = _bss_end_ofs - _bss_start_ofs;
+ memcpy((void*)bss_mirror, (void*)bss_start, bss_length);
+
for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
if ((*init_fnc_ptr)() != 0) {
hang ();
}
+ if (!break_bss)
+ if (memcmp((void*)bss_mirror, bss_start, bss_length) != 0)
+ break_bss = *init_fnc_ptr;
}

+ if (break_bss)
+ printf("BSS got corrupted after init_fnc @ 0x%p\n", *break_bss);
+ else
+ printf("BSS is still OK after init_fnc\n");
+
debug ("monitor len: %08lX\n", gd->mon_len);
/*
* Ram is setup, size stored in gd !!
--
1.7.3.2