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 GPLv3 license.
8 #include "util.h" // memcpy
9 #include "pci.h" // pci_config_writeb
11 // Test if 'addr' is in the range from 'start'..'start+size'
12 #define IN_RANGE(addr, start, size) ({ \
13 u32 __addr = (addr); \
14 u32 __start = (start); \
15 u32 __size = (size); \
16 (__addr - __start < __size); \
19 // Enable shadowing and copy bios.
21 copy_bios(PCIDevice d)
23 int v = pci_config_readb(d, 0x59);
25 pci_config_writeb(d, 0x59, v);
26 memcpy((void *)0x000f0000, (void *)BUILD_BIOS_TMP_ADDR, 0x10000);
29 // Make the BIOS code segment area (0xf0000) writable.
36 dprintf(3, "enabling shadow ram\n");
38 // Locate chip controlling ram shadowing.
40 int ret = pci_find_device(0x8086, 0x1237, 0, &d);
42 dprintf(1, "Unable to unlock ram - bridge not found\n");
46 // Copy the bios to a temporary area.
47 memcpy((void *)BUILD_BIOS_TMP_ADDR, (void *)0x000f0000, 0x10000);
49 // Enable shadowing and copy bios.
50 if (IN_RANGE((u32)copy_bios, 0xf0000, 0x10000)) {
51 // Jump to shadow enable function - use the copy in the
52 // temporary storage area so that memory does not change under
53 // the executing code.
54 u32 pos = (u32)copy_bios - 0xf0000 + BUILD_BIOS_TMP_ADDR;
55 void (*func)(PCIDevice) = (void*)pos;
61 // Clear the temporary area.
62 memset((void *)BUILD_BIOS_TMP_ADDR, 0, 0x10000);
65 // Make the BIOS code segment area (0xf0000) read-only.
72 dprintf(3, "locking shadow ram\n");
75 int ret = pci_find_device(0x8086, 0x1237, 0, &d);
77 dprintf(1, "Unable to lock ram - bridge not found\n");
82 int v = pci_config_readb(d, 0x59);
83 v = (v & 0x0f) | (0x10);
84 pci_config_writeb(d, 0x59, v);