Merge pull request #157 from paulusmack/master

Start using cache-inhibited loads and stores to access the UART

hello_world/Makefile

@@ -1,7 +1,7 @@
 ARCH = $(shell uname -m)
 ifneq ("$(ARCH)", "ppc64")
 ifneq ("$(ARCH)", "ppc64le")
-        CROSS_COMPILE = powerpc64le-linux-
+        CROSS_COMPILE ?= powerpc64le-linux-
         endif
         endif
 

hello_world/console.c

@@ -1,8 +1,8 @@
-#include <unistd.h>
-#include <string.h>
 #include <stdint.h>
 #include <stdbool.h>
 
+#include "console.h"
+
 /*
  * Core UART functions to implement for a port
  */
@@ -25,23 +25,16 @@ static uint64_t potato_uart_base;
 
 static uint64_t potato_uart_reg_read(int offset)
 {
-	uint64_t addr;
 	uint64_t val;
 
-	addr = potato_uart_base + offset;
+	__asm__ volatile("ldcix %0,%1,%2" : "=r" (val) : "b" (potato_uart_base), "r" (offset));
-
-	val = *(volatile uint64_t *)addr;
 
 	return val;
 }
 
 static void potato_uart_reg_write(int offset, uint64_t val)
 {
-	uint64_t addr;
+	__asm__ volatile("stdcix %0,%1,%2" : : "r" (val), "b" (potato_uart_base), "r" (offset));
-
-	addr = potato_uart_base + offset;
-
-	*(volatile uint64_t *)addr = val;
 }
 
 static int potato_uart_rx_empty(void)

hello_world/console.h

@@ -1,3 +1,5 @@
+#include <stddef.h>
+
 void potato_uart_init(void);
 int getchar(void);
 void putchar(unsigned char c);

hello_world/hello_world.c

@@ -1,5 +1,3 @@
-#include <unistd.h>
-#include <string.h>
 #include <stdint.h>
 #include <stdbool.h>
 

hello_world/hello_world.hex

@@ -40,7 +40,7 @@ a64b5a7d14004a39
 60211f0064210000
 618c00003d800000
 658c0000798c07c6
-7d8903a6618c113c
+7d8903a6618c1014
 480000004e800421
 0000000000000000
 0000000000000000
@@ -513,74 +513,55 @@ a64b5a7d14004a39
 e8010010ebc1fff0
 7c0803a6ebe1fff8
 3c4000014e800020
+7c0802a63842a000
+3fe2fffffbe1fff8
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+480000955463063e
+4bffffec60000000
+0100000000000000
+3c40000100000180
 3d20c0003842a000
 6129200060000000
-f922800079290020
+7929002039000018
-3940001a3d20c000
+3940001af9228000
-7929002061292018
+4e8000207d4947ea
-4e800020f9490000
 0000000000000000
 3c40000100000000
 600000003842a000
-390a0010e9428000
+39000010e9228000
-71290001e9280000
+794707e17d4946ea
-e86a00084082fff8
+386000084082fff8
-4e8000205463063e
+5463063e7c691eea
+000000004e800020
 0000000000000000
-3c40000100000000
+3842a0003c400001
-600000003842a000
+e942800060000000
-390a0010e9428000
+7d2a46ea39000010
-71290008e9280000
+4082fff87927efe3
-f86a00004082fff8
+7c6a4fea39200000
 000000004e800020
 0000000000000000
 3842a0003c400001
 fbc1fff07c0802a6
-7fc32214fbe1fff8
+3884fffffbe1fff8
-f80100107c7f1b78
+7fe322143bc3ffff
-7fbff040f821ffd1
+f821ffd1f8010010
-38210030409e000c
+419e00107fbef840
-887f00004bffff10
+4bffff9d8c7e0001
-4bffff993bff0001
+382100304bfffff0
-000000004bffffe4
+000000004bfffe98
 0000028001000000
 7d4348ae39200000
-409e000c2f8a0000
+419e000c2f8a0000
+4bfffff039290001
 4e8000207d234b78
-4bffffe839290001
 0000000000000000
-3c40000100000000
+0000000000000000
-7c0802a63842a000
-3fe2fffffbe1fff8
-f80100103bff7190
-4bfffec1f821ffd1
-4bffffad7fe3fb78
-7fe3fb787c641b78
-4bfffee94bffff59
-4bffff195463063e
-000000004bfffff4
-0000018001000000
 6f57206f6c6c6548
 0000000a0d646c72
-0000000000000010
-0141780400527a01
-0000001000010c1b
-fffffe5800000018
-0000000000000040
-0000002c00000010
-00000038fffffe84
-0000001000000000
-fffffea800000040
-0000000000000034
-0000005400000028
-00000050fffffec8
-9f029e0041094500
-437e4111300e4401
-4106dedf41000e0a
-000000100000000b
-fffffeec00000080
-000000000000002c
-000000940000001c
-00000054ffffff04
-44019f0041094400
-0000007e4111300e

tests/Makefile.test

@@ -1,7 +1,7 @@
 ARCH = $(shell uname -m)
 ifneq ("$(ARCH)", "ppc64")
 ifneq ("$(ARCH)", "ppc64le")
-        CROSS_COMPILE = powerpc64le-linux-
+        CROSS_COMPILE ?= powerpc64le-linux-
         endif
         endif
 

tests/decrementer/decrementer.c

@@ -1,5 +1,4 @@
-#include <unistd.h>
+#include <stddef.h>
-#include <string.h>
 #include <stdint.h>
 #include <stdbool.h>
 

tests/illegal/illegal.c

@@ -1,5 +1,4 @@
-#include <unistd.h>
+#include <stddef.h>
-#include <string.h>
 #include <stdint.h>
 #include <stdbool.h>
 

tests/sc/sc.c

@@ -1,5 +1,4 @@
-#include <unistd.h>
+#include <stddef.h>
-#include <string.h>
 #include <stdint.h>
 #include <stdbool.h>