[U-Boot] [RESEND PATCH v2 1/6] image: Use ram_top, not bi_memsize, in getenv_bootm_size

[Daniel Schwierzeck]

From: Paul Burton <paul.burton at imgtec.com>

When determining the region of memory to allow for use by bootm, using
bi_memstart & adding bi_memsize can cause problems if that leads to an
integer overflow. For example on some MIPS systems bi_memstart would be
0xffffffff80000000 (ie. the start of the MIPS ckseg0 region) and if the
system has 2GB of memory then the addition would wrap around to 0.

The maximum amount of memory to be used by U-Boot is already accounted
for by the ram_top field of struct global_data, so make use of that for
the calculation instead.

Signed-off-by: Paul Burton <paul.burton at imgtec.com>
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>

---

Changes in v2:
- also patch ARM specific code to get a consistent behaviour

 common/image.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/common/image.c b/common/image.c
index 0f88984f2d..160c4c6fbc 100644
--- a/common/image.c
+++ b/common/image.c
@@ -494,11 +494,10 @@ phys_size_t getenv_bootm_size(void)
 
 #if defined(CONFIG_ARM) && defined(CONFIG_NR_DRAM_BANKS)
 	start = gd->bd->bi_dram[0].start;
-	size = gd->bd->bi_dram[0].size;
 #else
 	start = gd->bd->bi_memstart;
-	size = gd->bd->bi_memsize;
 #endif
+	size = gd->ram_top - start;
 
 	s = getenv("bootm_low");
 	if (s)
-- 
2.11.0