[U-Boot] [PATCH v2 1/6] x86: Support machines with >4GB of RAM

Simon Glass sjg at chromium.org
Mon Mar 2 20:40:49 CET 2015


Some systems have more than 4GB of RAM. U-Boot can only place things below
4GB so any memory above that should not be used. Ignore any such memory so
that the memory size will not exceed the maximum.

This prevents gd->ram_size exceeding 4GB which causes problems for PCI
devices which use DMA.

Signed-off-by: Simon Glass <sjg at chromium.org>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
---

Changes in v2: None

 arch/x86/cpu/coreboot/sdram.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/cpu/coreboot/sdram.c b/arch/x86/cpu/coreboot/sdram.c
index e98a230..9c3ab81 100644
--- a/arch/x86/cpu/coreboot/sdram.c
+++ b/arch/x86/cpu/coreboot/sdram.c
@@ -90,7 +90,8 @@ int dram_init(void)
 		struct memrange *memrange = &lib_sysinfo.memrange[i];
 		unsigned long long end = memrange->base + memrange->size;
 
-		if (memrange->type == CB_MEM_RAM && end > ram_size)
+		if (memrange->type == CB_MEM_RAM && end > ram_size &&
+		    memrange->base < (1ULL << 32))
 			ram_size = end;
 	}
 	gd->ram_size = ram_size;
@@ -108,7 +109,8 @@ void dram_init_banksize(void)
 		for (i = 0, j = 0; i < lib_sysinfo.n_memranges; i++) {
 			struct memrange *memrange = &lib_sysinfo.memrange[i];
 
-			if (memrange->type == CB_MEM_RAM) {
+			if (memrange->type == CB_MEM_RAM &&
+			    memrange->base < (1ULL << 32)) {
 				gd->bd->bi_dram[j].start = memrange->base;
 				gd->bd->bi_dram[j].size = memrange->size;
 				j++;
-- 
2.2.0.rc0.207.ga3a616c



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