sandbox: Add improved RAM simulation

Using mmap to allocate memory from the OS for RAM simulation we can use
u-boot own malloc implementation.

Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Matthias Weisser <weisserm@arcor.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/sandbox/cpu/os.c

@@ -25,6 +25,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/mman.h>
 
 #include <os.h>
 
@@ -87,3 +88,9 @@ void os_tty_raw(int fd)
 
 	atexit(os_fd_restore);
 }
+
+void *os_malloc(size_t length)
+{
+	return mmap(NULL, length, PROT_READ | PROT_WRITE,
+			MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+}

arch/sandbox/lib/board.c

@@ -45,8 +45,12 @@
 #include <version.h>
 #include <serial.h>
 
+#include <os.h>
+
 DECLARE_GLOBAL_DATA_PTR;
 
+static gd_t gd_mem;
+
 /************************************************************************
  * Init Utilities							*
  ************************************************************************
@@ -147,7 +151,7 @@ void board_init_f(ulong bootflag)
 	uchar *mem;
 	unsigned long addr_sp, addr, size;
 
-	gd = malloc(sizeof(gd_t));
+	gd = &gd_mem;
 	assert(gd);
 
 	memset((void *)gd, 0, sizeof(gd_t));
@@ -158,7 +162,8 @@ void board_init_f(ulong bootflag)
 	}
 
 	size = CONFIG_SYS_SDRAM_SIZE;
-	mem = malloc(size);
+	mem = os_malloc(CONFIG_SYS_SDRAM_SIZE);
+
 	assert(mem);
 	gd->ram_buf = mem;
 	addr = (ulong)(mem + size);
@@ -214,11 +219,9 @@ void board_init_r(gd_t *id, ulong dest_addr)
 	post_output_backlog();
 #endif
 
-#if 0 /* Sandbox uses system malloc for now */
-	/* The Malloc area is immediately below the monitor copy in DRAM */
-	malloc_start = dest_addr - TOTAL_MALLOC_LEN;
-	mem_malloc_init(malloc_start, TOTAL_MALLOC_LEN);
-#endif
+	/* The Malloc area is at the top of simulated DRAM */
+	mem_malloc_init((ulong)gd->ram_buf + gd->ram_size - TOTAL_MALLOC_LEN,
+			TOTAL_MALLOC_LEN);
 
 	/* initialize environment */
 	env_relocate();

common/Makefile

@@ -29,9 +29,6 @@ LIB	= $(obj)libcommon.o
 ifndef CONFIG_SPL_BUILD
 COBJS-y += main.o
 COBJS-y += command.o
-ifndef CONFIG_SANDBOX
-COBJS-y += dlmalloc.o
-endif
 COBJS-y += exports.o
 COBJS-$(CONFIG_SYS_HUSH_PARSER) += hush.o
 COBJS-y += image.o

include/os.h

@@ -76,3 +76,11 @@ void os_exit(int exit_code);
  * Put tty into raw mode to mimic serial console better
  */
 void os_tty_raw(int fd);
+
+/**
+ * Acquires some memory from the underlying os.
+ *
+ * \param length	Number of bytes to be allocated
+ * \return Pointer to length bytes or NULL on error
+ */
+void *os_malloc(size_t length);