[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH] [0.12] Map BIOS f-segment as RAM, not as ROM
From: |
Alexander Graf |
Subject: |
[Qemu-devel] [PATCH] [0.12] Map BIOS f-segment as RAM, not as ROM |
Date: |
Fri, 4 Dec 2009 01:24:52 +0100 |
SeaBIOS needs to write to the f-segment. So it needs to have some way to set
that from read-only to read-write, write in it and when it's done set it to
read-only again.
On PCI we have a mechanism for that. The ISA machine does not though. To stay
regression free and happily enable users to continue using the -M isapc machine
let's just map it as RAM on the ISA PC.
Signed-off-by: Alexander Graf <address@hidden>
---
hw/pc.c | 22 ++++++++++++++++++++--
1 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/hw/pc.c b/hw/pc.c
index 8c1b7ea..90373cf 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -982,7 +982,7 @@ static void pc_init1(ram_addr_t ram_size,
int ret, linux_boot, i;
ram_addr_t ram_addr, bios_offset, option_rom_offset;
ram_addr_t below_4g_mem_size, above_4g_mem_size = 0;
- int bios_size, isa_bios_size;
+ int bios_size, isa_bios_size, f_seg_type;
PCIBus *pci_bus;
ISADevice *isa_dev;
int piix3_devfn = -1;
@@ -1073,9 +1073,27 @@ static void pc_init1(ram_addr_t ram_size,
isa_bios_size = bios_size;
if (isa_bios_size > (128 * 1024))
isa_bios_size = 128 * 1024;
+
+ /* XXX
+ *
+ * Usually we would map this region read only, have the BIOS set it r/w
+ * when it needs to and have the BIOS also set it r/o when it's done
+ * messing with it.
+ *
+ * Unfortunately we don't export any device to the ISA PC machine that
+ * could do the r/w <-> r/o transition, so let's just always map it r/w
+ * there for now.
+ */
+
+ if (pci_enabled) {
+ f_seg_type = IO_MEM_ROM;
+ } else {
+ f_seg_type = 0;
+ }
+
cpu_register_physical_memory(0x100000 - isa_bios_size,
isa_bios_size,
- (bios_offset + bios_size - isa_bios_size) |
IO_MEM_ROM);
+ (bios_offset + bios_size - isa_bios_size) |
f_seg_type);
--
1.6.0.2
- [Qemu-devel] [PATCH] [0.12] Map BIOS f-segment as RAM, not as ROM,
Alexander Graf <=