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authorYatharth Kochar <yatharth.kochar@arm.com>2016-09-28 11:00:05 +0100
committerYatharth Kochar <yatharth.kochar@arm.com>2016-09-28 14:03:47 +0100
commit9c1dceb106474966211a3782f8e89e195b4c079c (patch)
treefdac31949604c93e82fd9a535c07bce5baa9a826 /lib/aarch32
parentbfd925139fdbc2e87979849907b34843aa326994 (diff)
downloadtrusted-firmware-a-9c1dceb106474966211a3782f8e89e195b4c079c.tar.gz
AArch32: Add `memcpy4` function in assembly
At present the `el3_entrypoint_common` macro uses `memcpy` function defined in lib/stdlib/mem.c file, to copy data from ROM to RAM for BL1. Depending on the compiler being used the stack could potentially be used, in `memcpy`, for storing the local variables. Since the stack is initialized much later in `el3_entrypoint_common` it may result in unknown behaviour. This patch adds `memcpy4` function definition in assembly so that it can be used before the stack is initialized and it also replaces `memcpy` by `memcpy4` in `el3_entrypoint_common` macro, to copy data from ROM to RAM for BL1. Change-Id: I3357a0e8095f05f71bbbf0b185585d9499bfd5e0
Diffstat (limited to 'lib/aarch32')
-rw-r--r--lib/aarch32/misc_helpers.S35
1 files changed, 35 insertions, 0 deletions
diff --git a/lib/aarch32/misc_helpers.S b/lib/aarch32/misc_helpers.S
index fd7c6dd159..bf4084a828 100644
--- a/lib/aarch32/misc_helpers.S
+++ b/lib/aarch32/misc_helpers.S
@@ -34,6 +34,7 @@
.globl smc
.globl zeromem
+ .globl memcpy4
.globl disable_mmu_icache_secure
.globl disable_mmu_secure
@@ -73,6 +74,40 @@ z_end:
bx lr
endfunc zeromem
+/* --------------------------------------------------------------------------
+ * void memcpy4(void *dest, const void *src, unsigned int length)
+ *
+ * Copy length bytes from memory area src to memory area dest.
+ * The memory areas should not overlap.
+ * Destination and source addresses must be 4-byte aligned.
+ * --------------------------------------------------------------------------
+ */
+func memcpy4
+#if ASM_ASSERTION
+ orr r3, r0, r1
+ tst r3, #0x3
+ ASM_ASSERT(eq)
+#endif
+/* copy 4 bytes at a time */
+m_loop4:
+ cmp r2, #4
+ blt m_loop1
+ ldr r3, [r1], #4
+ str r3, [r0], #4
+ sub r2, r2, #4
+ b m_loop4
+/* copy byte per byte */
+m_loop1:
+ cmp r2,#0
+ beq m_end
+ ldrb r3, [r1], #1
+ strb r3, [r0], #1
+ subs r2, r2, #1
+ bne m_loop1
+m_end:
+ bx lr
+endfunc memcpy4
+
/* ---------------------------------------------------------------------------
* Disable the MMU in Secure State
* ---------------------------------------------------------------------------