X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=cpu%2Fattr.h;h=a95dffdc198fe47364c531164beca27ff9ea7d19;hb=49d4f9b278ec7da35bbf2dcd3f5013940d1a74e3;hp=678eac68287f010ea70002a962f8cc115a4fc9e1;hpb=efbdba7e2814415234ef47bd10ff888559ea90af;p=bertos.git

diff --git a/cpu/attr.h b/cpu/attr.h
index 678eac68..a95dffdc 100644
--- a/cpu/attr.h
+++ b/cpu/attr.h
@@ -102,7 +102,8 @@
 	#define CPU_SAVED_REGS_CNT     9
 	#define CPU_STACK_GROWS_UPWARD 0
 	#define CPU_SP_ON_EMPTY_SLOT   0
-	#define CPU_BYTE_ORDER         (__BIG_ENDIAN__ ? CPU_BIG_ENDIAN : CPU_LITTLE_ENDIAN)
+	#warning Find a way to detect endianess at compile time
+	#define CPU_BYTE_ORDER         CPU_LITTLE_ENDIAN
 	#define CPU_HARVARD            0
 
 	#ifdef __IAR_SYSTEMS_ICC__
@@ -256,6 +257,30 @@
 			CPU_PUSH_WORD((sp), funcaddr>>8); \
 		} while (0)
 
+	/*
+	 * If the kernel is in idle-spinning, the processor execute:
+	 * 
+	 * IRQ_ENABLE;
+	 * CPU_IDLE;
+	 * IRQ_DISABLE;
+	 *
+	 * IRQ_ENABLE is translated in asm as "sei" and IRQ_DISABLE as "cli".
+	 * We could define CPU_IDLE to expand to none, so the resulting
+	 * asm code would be:
+	 *
+	 * sei;
+	 * cli;
+	 *
+	 * But Atmel datasheet states:
+	 * "When using the SEI instruction to enable interrupts,
+	 * the instruction following SEI will be executed *before*
+	 * any pending interrupts", so "cli" is executed before any
+	 * pending interrupt with the result that IRQs will *NOT*
+	 * be enabled!
+	 * To ensure that IRQ will run a NOP is required.
+	 */
+	#define CPU_IDLE NOP
+
 #else
 	#define CPU_PUSH_CALL_CONTEXT(sp, func) \
 		CPU_PUSH_WORD((sp), (cpustack_t)(func))