[OpenBIOS] [PATCH 5/5] Change OFMEM to allocate memory from the top of RAM downwards.

Mark Cave-Ayland mark.cave-ayland at siriusit.co.uk
Tue Dec 21 11:38:40 CET 2010


At the moment OFMEM allocates memory from the bottom of RAM upwards, however many loaders/kernels initialise themselves in lower
memory areas which can cause them to be overwritten by subsequent memory allocations. Mimic the existing SPARC32 behaviour by
allocating physical and virtual memory from the top of RAM downwards.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland at siriusit.co.uk>
---
 openbios-devel/libopenbios/ofmem_common.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/openbios-devel/libopenbios/ofmem_common.c b/openbios-devel/libopenbios/ofmem_common.c
index f235e98..97493e6 100644
--- a/openbios-devel/libopenbios/ofmem_common.c
+++ b/openbios-devel/libopenbios/ofmem_common.c
@@ -498,7 +498,7 @@ phys_addr_t ofmem_claim_phys( phys_addr_t phys, ucell size, ucell align )
                 " align=" FMT_ucellx "\n",
                 phys, size, align);
 
-	return ofmem_claim_phys_( phys, size, align, 0, get_ram_size(), 0 );
+	return ofmem_claim_phys_( phys, size, align, 0, ofmem_arch_get_phys_top(), 1 );
 }
 
 static ucell ofmem_claim_virt_( ucell virt, ucell size, ucell align,
@@ -531,7 +531,7 @@ ucell ofmem_claim_virt( ucell virt, ucell size, ucell align )
 
 	/* printk("+ ofmem_claim virt %08lx %lx %ld\n", virt, size, align ); */
 	return ofmem_claim_virt_( virt, size, align,
-			get_ram_size(), ofmem_arch_get_virt_top(), 0 );
+			get_ram_size(), ofmem_arch_get_virt_top(), 1 );
 }
 
 /* if align != 0, phys is ignored. Returns -1 on error */
-- 
1.7.1




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