Introduce crash console APIs for crash reporting
This patch introduces platform APIs to initialise and
print a character on a designated crash console.
For the FVP platform, PL011_UART0 is the designated
crash console. The platform porting guide is also updated
to document the new APIs.
Change-Id: I5e97d8762082e0c88c8c9bbb479353eac8f11a66
diff --git a/include/common/asm_macros.S b/include/common/asm_macros.S
index 2bccf58..238fa82 100644
--- a/include/common/asm_macros.S
+++ b/include/common/asm_macros.S
@@ -162,3 +162,36 @@
.macro get_up_stack _name, _size
ldr x0, =(\_name + \_size)
.endm
+
+ /*
+ * Helper macro to generate the best mov/movk combinations according
+ * the value to be moved. The 16 bits from '_shift' are tested and
+ * if not zero, they are moved into '_reg' without affecting
+ * other bits.
+ */
+ .macro _mov_imm16 _reg, _val, _shift
+ .if (\_val >> \_shift) & 0xffff
+ .if (\_val & (1 << \_shift - 1))
+ movk \_reg, (\_val >> \_shift) & 0xffff, LSL \_shift
+ .else
+ mov \_reg, \_val & (0xffff << \_shift)
+ .endif
+ .endif
+ .endm
+
+ /*
+ * Helper macro to load arbitrary values into 32 or 64-bit registers
+ * which generates the best mov/movk combinations. Many base addresses
+ * are 64KB aligned the macro will eliminate updating bits 15:0 in
+ * that case
+ */
+ .macro mov_imm _reg, _val
+ .if (\_val) == 0
+ mov \_reg, #0
+ .else
+ _mov_imm16 \_reg, (\_val), 0
+ _mov_imm16 \_reg, (\_val), 16
+ _mov_imm16 \_reg, (\_val), 32
+ _mov_imm16 \_reg, (\_val), 48
+ .endif
+ .endm