[SeaBIOS] [PATCH 2/4] piix: fix mtrr setup

[Gerd Hoffmann]

Add a piix4 memory setup function to make the control flow more clear.

Set the new mtrr_base variable to the start of the 32bit pci window to
make sure the mtrr entry added covers the I/O window.

Make the 32bit pci window start at 0x80000000, 0xc0000000 or 0xe000000
(depending on the memory installed) so we can cover the whole window
with a single mtrr entry.

Signed-off-by: Gerd Hoffmann <kraxel at redhat.com>
---
 src/pciinit.c |   19 +++++++++++++++++++
 1 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/src/pciinit.c b/src/pciinit.c
index 0b4a9e4..137c667 100644
--- a/src/pciinit.c
+++ b/src/pciinit.c
@@ -597,10 +597,29 @@ static void pci_region_map_entries(struct pci_bus *busses, struct pci_region *r)
     }
 }
 
+void i440fx_mem_addr_init(struct pci_device *dev, void *arg)
+{
+    if (RamSize <= 0x80000000)
+        pcimem_start = 0x80000000;
+    else if (RamSize <= 0xc0000000)
+        pcimem_start = 0xc0000000;
+
+    mtrr_base = pcimem_start;
+}
+
+static const struct pci_device_id pci_mem_addr_tbl[] = {
+    PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82441,
+               i440fx_mem_addr_init),
+    PCI_DEVICE_END,
+};
+
 static void pci_bios_map_devices(struct pci_bus *busses)
 {
     pcimem_start = RamSize;
 
+    /* chipset specific memory setup */
+    pci_find_init_device(pci_mem_addr_tbl, NULL);
+
     if (pci_bios_init_root_regions(busses)) {
         struct pci_region r64_mem, r64_pref;
         r64_mem.list = NULL;
-- 
1.7.1