Patchwork [v4,3/7] hw/vexpress.c: Move secondary CPU boot code to SRAM

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Submitter Peter Maydell
Date Feb. 3, 2012, 6:30 p.m.
Message ID <1328293828-21921-4-git-send-email-peter.maydell@linaro.org>
Download mbox | patch
Permalink /patch/139436/
State New
Headers show

Comments

Peter Maydell - Feb. 3, 2012, 6:30 p.m.
On real Versatile Express hardware, the boot ROM puts the secondary
CPU bootcode/holding pen in SRAM. We can therefore rely on Linux not
trashing this memory until secondary CPUs have booted up, and can
put our QEMU-specific pen code in the same place. This allows us to
drop the odd "hack" RAM page we were using before.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/vexpress.c |   16 ++--------------
 1 files changed, 2 insertions(+), 14 deletions(-)

Patch

diff --git a/hw/vexpress.c b/hw/vexpress.c
index 8c4d3b3..99a9690 100644
--- a/hw/vexpress.c
+++ b/hw/vexpress.c
@@ -30,13 +30,9 @@ 
 #include "boards.h"
 #include "exec-memory.h"
 
-#define SMP_BOOT_ADDR 0xe0000000
-
 #define VEXPRESS_BOARD_ID 0x8e0
 
-static struct arm_boot_info vexpress_binfo = {
-    .smp_loader_start = SMP_BOOT_ADDR,
-};
+static struct arm_boot_info vexpress_binfo;
 
 /* Address maps for peripherals:
  * the Versatile Express motherboard has two possible maps,
@@ -118,7 +114,6 @@  static void vexpress_a9_init(ram_addr_t ram_size,
     MemoryRegion *lowram = g_new(MemoryRegion, 1);
     MemoryRegion *vram = g_new(MemoryRegion, 1);
     MemoryRegion *sram = g_new(MemoryRegion, 1);
-    MemoryRegion *hackram = g_new(MemoryRegion, 1);
     DeviceState *dev, *sysctl, *pl041;
     SysBusDevice *busdev;
     qemu_irq *irqp;
@@ -275,14 +270,6 @@  static void vexpress_a9_init(ram_addr_t ram_size,
 
     /* VE_DAPROM: not modelled */
 
-    /* ??? Hack to map an additional page of ram for the secondary CPU
-       startup code.  I guess this works on real hardware because the
-       BootROM happens to be in ROM/flash or in memory that isn't clobbered
-       until after Linux boots the secondary CPUs.  */
-    memory_region_init_ram(hackram, "vexpress.hack", 0x1000);
-    vmstate_register_ram_global(hackram);
-    memory_region_add_subregion(sysmem, SMP_BOOT_ADDR, hackram);
-
     vexpress_binfo.ram_size = ram_size;
     vexpress_binfo.kernel_filename = kernel_filename;
     vexpress_binfo.kernel_cmdline = kernel_cmdline;
@@ -290,6 +277,7 @@  static void vexpress_a9_init(ram_addr_t ram_size,
     vexpress_binfo.nb_cpus = smp_cpus;
     vexpress_binfo.board_id = VEXPRESS_BOARD_ID;
     vexpress_binfo.loader_start = 0x60000000;
+    vexpress_binfo.smp_loader_start = map[VE_SRAM];
     vexpress_binfo.smp_bootreg_addr = map[VE_SYSREGS] + 0x30;
     arm_load_kernel(first_cpu, &vexpress_binfo);
 }