1 // Support for enabling/disabling BIOS ram shadowing.
3 // Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
4 // Copyright (C) 2006 Fabrice Bellard
6 // This file may be distributed under the terms of the GNU LGPLv3 license.
8 #include "util.h" // memcpy
9 #include "pci.h" // pci_config_writeb
10 #include "config.h" // CONFIG_*
11 #include "pci_ids.h" // PCI_VENDOR_ID_INTEL
13 // Test if 'addr' is in the range from 'start'..'start+size'
14 #define IN_RANGE(addr, start, size) ({ \
15 u32 __addr = (addr); \
16 u32 __start = (start); \
17 u32 __size = (size); \
18 (__addr - __start < __size); \
21 // On the emulators, the bios at 0xf0000 is also at 0xffff0000
22 #define BIOS_SRC_ADDR 0xffff0000
24 // Enable shadowing and copy bios.
26 copy_bios(u16 bdf, int reg)
28 pci_config_writeb(bdf, 0x59, reg | 0x30);
29 memcpy((void*)BUILD_BIOS_ADDR, (void*)BIOS_SRC_ADDR, BUILD_BIOS_SIZE);
32 // Make the BIOS code segment area (0xf0000) writable.
39 dprintf(3, "enabling shadow ram\n");
41 // Locate chip controlling ram shadowing.
42 int bdf = pci_find_device(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82441);
44 dprintf(1, "Unable to unlock ram - bridge not found\n");
48 int reg = pci_config_readb(bdf, 0x59);
50 // Ram already present - just enable writes
51 pci_config_writeb(bdf, 0x59, reg | 0x30);
55 // Enable shadowing and copy bios.
56 if (IN_RANGE((u32)copy_bios, BUILD_BIOS_ADDR, BUILD_BIOS_SIZE)) {
57 // Jump to shadow enable function - use the copy in the
58 // temporary storage area so that memory does not change under
59 // the executing code.
60 u32 pos = (u32)copy_bios - BUILD_BIOS_ADDR + BIOS_SRC_ADDR;
61 void (*func)(u16 bdf, int reg) = (void*)pos;
68 // Make the BIOS code segment area (0xf0000) read-only.
75 dprintf(3, "locking shadow ram\n");
77 int bdf = pci_find_device(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82441);
79 dprintf(1, "Unable to lock ram - bridge not found\n");
84 int v = pci_config_readb(bdf, 0x59);
85 v = (v & 0x0f) | (0x10);
86 pci_config_writeb(bdf, 0x59, v);