[PATCH 4/6] hw/arm/raspi: Get board RAM size from board revision code

[Philippe Mathieu-Daudé]

The amount of RAM is encoded in the board revision.
Add the board_ram_size() helper, it will allow us to quickly
support new boards.

Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
 hw/arm/raspi.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/hw/arm/raspi.c b/hw/arm/raspi.c
index f5e54fe876..656d834e07 100644
--- a/hw/arm/raspi.c
+++ b/hw/arm/raspi.c
@@ -13,6 +13,7 @@
 
 #include "qemu/osdep.h"
 #include "qemu/units.h"
+#include "qemu/cutils.h"
 #include "qapi/error.h"
 #include "cpu.h"
 #include "hw/arm/bcm2836.h"
@@ -71,6 +72,11 @@ static const RaspiBoardInfo raspi_boards[] = {
 #endif
 };
 
+static uint64_t board_ram_size(const RaspiBoardInfo *config)
+{
+    return 1 * MiB << extract32(config->board_rev, 20, 4);
+}
+
 static int board_chip_id(const RaspiBoardInfo *config)
 {
     return extract32(config->board_rev, 12, 4);
@@ -222,10 +228,13 @@ static void raspi_init(MachineState *machine, const 
RaspiBoardInfo *config)
     BlockBackend *blk;
     BusState *bus;
     DeviceState *carddev;
+    uint64_t ram_size;
 
-    if (machine->ram_size > 1 * GiB) {
-        error_report("Requested ram size is too large for this machine: "
-                     "maximum is 1GB");
+    ram_size = board_ram_size(config);
+    if (machine->ram_size != ram_size) {
+        char *size_str = size_to_str(ram_size);
+        error_report("This machine can only be used with %s", size_str);
+        g_free(size_str);
         exit(1);
     }
 
-- 
2.21.1