/* * bios32.c - BIOS32, PCI BIOS functions. * * $Id: bios32.c,v 1.1 1999/04/26 05:50:57 tb Exp $ * * Sponsored by * iX Multiuser Multitasking Magazine * Hannover, Germany * hm@ix.de * * Copyright 1993, 1994 Drew Eckhardt * Visionary Computing * (Unix and Linux consulting and custom programming) * Drew@Colorado.EDU * +1 (303) 786-7975 * * For more information, please consult * * PCI BIOS Specification Revision * PCI Local Bus Specification * PCI System Design Guide * * PCI Special Interest Group * M/S HF3-15A * 5200 N.E. Elam Young Parkway * Hillsboro, Oregon 97124-6497 * +1 (503) 696-2000 * +1 (800) 433-5177 * * Manuals are $25 each or $50 for all three, plus $7 shipping * within the United States, $35 abroad. * * * CHANGELOG : * Jun 17, 1994 : Modified to accommodate the broken pre-PCI BIOS SPECIFICATION * Revision 2.0 present on 's ASUS mainboard. * * Jan 5, 1995 : Modified to probe PCI hardware at boot time by Frederic * Potter, potter@cao-vlsi.ibp.fr * * Jan 10, 1995 : Modified to store the information about configured pci * devices into a list, which can be accessed via /proc/pci by * Curtis Varner, cvarner@cs.ucr.edu * * Jan 12, 1995 : CPU-PCI bridge optimization support by Frederic Potter. * Alpha version. Intel & UMC chipset support only. * * Apr 16, 1995 : Source merge with the DEC Alpha PCI support. Most of the code * moved to drivers/pci/pci.c. * * Dec 7, 1996 : Added support for direct configuration access of boards * with Intel compatible access schemes (tsbogend@alpha.franken.de) * * Feb 3, 1997 : Set internal functions to static, save/restore flags * avoid dead locks reading broken PCI BIOS, werner@suse.de * * Apr 26, 1997 : Fixed case when there is BIOS32, but not PCI BIOS * (mj@atrey.karlin.mff.cuni.cz) * * May 7, 1997 : Added some missing cli()'s. [mj] * * Jun 20, 1997 : Corrected problems in "conf1" type accesses. * (paubert@iram.es) */ #include #include #include #include #include #include #include #include #define PCIBIOS_PCI_FUNCTION_ID 0xb1XX #define PCIBIOS_PCI_BIOS_PRESENT 0xb101 #define PCIBIOS_FIND_PCI_DEVICE 0xb102 #define PCIBIOS_FIND_PCI_CLASS_CODE 0xb103 #define PCIBIOS_GENERATE_SPECIAL_CYCLE 0xb106 #define PCIBIOS_READ_CONFIG_BYTE 0xb108 #define PCIBIOS_READ_CONFIG_WORD 0xb109 #define PCIBIOS_READ_CONFIG_DWORD 0xb10a #define PCIBIOS_WRITE_CONFIG_BYTE 0xb10b #define PCIBIOS_WRITE_CONFIG_WORD 0xb10c #define PCIBIOS_WRITE_CONFIG_DWORD 0xb10d /* BIOS32 signature: "_32_" */ #define BIOS32_SIGNATURE (('_' << 0) + ('3' << 8) + ('2' << 16) + ('_' << 24)) /* PCI signature: "PCI " */ #define PCI_SIGNATURE (('P' << 0) + ('C' << 8) + ('I' << 16) + (' ' << 24)) /* PCI service signature: "$PCI" */ #define PCI_SERVICE (('$' << 0) + ('P' << 8) + ('C' << 16) + ('I' << 24)) /* * This is the standard structure used to identify the entry point * to the BIOS32 Service Directory, as documented in * Standard BIOS 32-bit Service Directory Proposal * Revision 0.4 May 24, 1993 * Phoenix Technologies Ltd. * Norwood, MA * and the PCI BIOS specification. */ union bios32 { struct { unsigned long signature; /* _32_ */ unsigned long entry; /* 32 bit physical address */ unsigned char revision; /* Revision level, 0 */ unsigned char length; /* Length in paragraphs should be 01 */ unsigned char checksum; /* All bytes must add up to zero */ unsigned char reserved[5]; /* Must be zero */ } fields; char chars[16]; }; #ifdef CONFIG_PCI /* * Physical address of the service directory. I don't know if we're * allowed to have more than one of these or not, so just in case * we'll make pcibios_present() take a memory start parameter and store * the array there. */ static unsigned long bios32_entry = 0; static struct { unsigned long address; unsigned short segment; } bios32_indirect = { 0, KERNEL_CS }; /* * function table for accessing PCI configuration space */ struct pci_access { int (*find_device)(unsigned short, unsigned short, unsigned short, unsigned char *, unsigned char *); int (*find_class)(unsigned int, unsigned short, unsigned char *, unsigned char *); int (*read_config_byte)(unsigned char, unsigned char, unsigned char, unsigned char *); int (*read_config_word)(unsigned char, unsigned char, unsigned char, unsigned short *); int (*read_config_dword)(unsigned char, unsigned char, unsigned char, unsigned int *); int (*write_config_byte)(unsigned char, unsigned char, unsigned char, unsigned char); int (*write_config_word)(unsigned char, unsigned char, unsigned char, unsigned short); int (*write_config_dword)(unsigned char, unsigned char, unsigned char, unsigned int); }; /* * pointer to selected PCI access function table */ static struct pci_access *access_pci = NULL; /* * Returns the entry point for the given service, NULL on error */ static unsigned long bios32_service(unsigned long service) { unsigned char return_code; /* %al */ unsigned long address; /* %ebx */ unsigned long length; /* %ecx */ unsigned long entry; /* %edx */ unsigned long flags; save_flags(flags); cli(); __asm__("lcall *(%%edi)" : "=a" (return_code), "=b" (address), "=c" (length), "=d" (entry) : "0" (service), "1" (0), "D" (&bios32_indirect)); restore_flags(flags); switch (return_code) { case 0: return address + entry; case 0x80: /* Not present */ printk("bios32_service(0x%lx) : not present\n", service); return 0; default: /* Shouldn't happen */ printk("bios32_service(0x%lx) : returned 0x%x, mail drew@colorado.edu\n", service, return_code); return 0; } } static long pcibios_entry = 0; static struct { unsigned long address; unsigned short segment; } pci_indirect = { 0, KERNEL_CS }; static int check_pcibios(void) { unsigned long signature; unsigned char present_status; unsigned char major_revision; unsigned char minor_revision; unsigned long flags; int pack; if ((pcibios_entry = bios32_service(PCI_SERVICE))) { pci_indirect.address = pcibios_entry; save_flags(flags); cli(); __asm__("lcall *(%%edi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" "1:\tshl $8, %%eax\n\t" "movw %%bx, %%ax" : "=d" (signature), "=a" (pack) : "1" (PCIBIOS_PCI_BIOS_PRESENT), "D" (&pci_indirect) : "bx", "cx"); restore_flags(flags); present_status = (pack >> 16) & 0xff; major_revision = (pack >> 8) & 0xff; minor_revision = pack & 0xff; if (present_status || (signature != PCI_SIGNATURE)) { printk ("pcibios_init : %s : BIOS32 Service Directory says PCI BIOS is present,\n" " but PCI_BIOS_PRESENT subfunction fails with present status of 0x%x\n" " and signature of 0x%08lx (%c%c%c%c). mail drew@Colorado.EDU\n", (signature == PCI_SIGNATURE) ? "WARNING" : "ERROR", present_status, signature, (char) (signature >> 0), (char) (signature >> 8), (char) (signature >> 16), (char) (signature >> 24)); if (signature != PCI_SIGNATURE) pcibios_entry = 0; } if (pcibios_entry) { printk ("pcibios_init : PCI BIOS revision %x.%02x entry at 0x%lx\n", major_revision, minor_revision, pcibios_entry); return 1; } } return 0; } static int pci_bios_find_class (unsigned int class_code, unsigned short index, unsigned char *bus, unsigned char *device_fn) { unsigned long bx; unsigned long ret; unsigned long flags; save_flags(flags); cli(); __asm__ ("lcall *(%%edi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" "1:" : "=b" (bx), "=a" (ret) : "1" (PCIBIOS_FIND_PCI_CLASS_CODE), "c" (class_code), "S" ((int) index), "D" (&pci_indirect)); restore_flags(flags); *bus = (bx >> 8) & 0xff; *device_fn = bx & 0xff; return (int) (ret & 0xff00) >> 8; } static int pci_bios_find_device (unsigned short vendor, unsigned short device_id, unsigned short index, unsigned char *bus, unsigned char *device_fn) { unsigned short bx; unsigned short ret; unsigned long flags; save_flags(flags); cli(); __asm__("lcall *(%%edi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" "1:" : "=b" (bx), "=a" (ret) : "1" (PCIBIOS_FIND_PCI_DEVICE), "c" (device_id), "d" (vendor), "S" ((int) index), "D" (&pci_indirect)); restore_flags(flags); *bus = (bx >> 8) & 0xff; *device_fn = bx & 0xff; return (int) (ret & 0xff00) >> 8; } static int pci_bios_read_config_byte(unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char *value) { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; unsigned long flags; save_flags(flags); cli(); __asm__("lcall *(%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" "1:" : "=c" (*value), "=a" (ret) : "1" (PCIBIOS_READ_CONFIG_BYTE), "b" (bx), "D" ((long) where), "S" (&pci_indirect)); restore_flags(flags); return (int) (ret & 0xff00) >> 8; } static int pci_bios_read_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short *value) { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; unsigned long flags; save_flags(flags); cli(); __asm__("lcall *(%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" "1:" : "=c" (*value), "=a" (ret) : "1" (PCIBIOS_READ_CONFIG_WORD), "b" (bx), "D" ((long) where), "S" (&pci_indirect)); restore_flags(flags); return (int) (ret & 0xff00) >> 8; } static int pci_bios_read_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int *value) { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; unsigned long flags; save_flags(flags); cli(); __asm__("lcall *(%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" "1:" : "=c" (*value), "=a" (ret) : "1" (PCIBIOS_READ_CONFIG_DWORD), "b" (bx), "D" ((long) where), "S" (&pci_indirect)); restore_flags(flags); return (int) (ret & 0xff00) >> 8; } static int pci_bios_write_config_byte (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char value) { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; unsigned long flags; save_flags(flags); cli(); __asm__("lcall *(%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" "1:" : "=a" (ret) : "0" (PCIBIOS_WRITE_CONFIG_BYTE), "c" (value), "b" (bx), "D" ((long) where), "S" (&pci_indirect)); restore_flags(flags); return (int) (ret & 0xff00) >> 8; } static int pci_bios_write_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short value) { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; unsigned long flags; save_flags(flags); cli(); __asm__("lcall *(%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" "1:" : "=a" (ret) : "0" (PCIBIOS_WRITE_CONFIG_WORD), "c" (value), "b" (bx), "D" ((long) where), "S" (&pci_indirect)); restore_flags(flags); return (int) (ret & 0xff00) >> 8; } static int pci_bios_write_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int value) { unsigned long ret; unsigned long bx = (bus << 8) | device_fn; unsigned long flags; save_flags(flags); cli(); __asm__("lcall *(%%esi)\n\t" "jc 1f\n\t" "xor %%ah, %%ah\n" "1:" : "=a" (ret) : "0" (PCIBIOS_WRITE_CONFIG_DWORD), "c" (value), "b" (bx), "D" ((long) where), "S" (&pci_indirect)); restore_flags(flags); return (int) (ret & 0xff00) >> 8; } /* * function table for BIOS32 access */ static struct pci_access pci_bios_access = { pci_bios_find_device, pci_bios_find_class, pci_bios_read_config_byte, pci_bios_read_config_word, pci_bios_read_config_dword, pci_bios_write_config_byte, pci_bios_write_config_word, pci_bios_write_config_dword }; /* * Given the vendor and device ids, find the n'th instance of that device * in the system. */ static int pci_direct_find_device (unsigned short vendor, unsigned short device_id, unsigned short index, unsigned char *bus, unsigned char *devfn) { unsigned int curr = 0; struct pci_dev *dev; for (dev = pci_devices; dev; dev = dev->next) { if (dev->vendor == vendor && dev->device == device_id) { if (curr == index) { *devfn = dev->devfn; *bus = dev->bus->number; return PCIBIOS_SUCCESSFUL; } ++curr; } } return PCIBIOS_DEVICE_NOT_FOUND; } /* * Given the class, find the n'th instance of that device * in the system. */ static int pci_direct_find_class (unsigned int class_code, unsigned short index, unsigned char *bus, unsigned char *devfn) { unsigned int curr = 0; struct pci_dev *dev; for (dev = pci_devices; dev; dev = dev->next) { if (dev->class == class_code) { if (curr == index) { *devfn = dev->devfn; *bus = dev->bus->number; return PCIBIOS_SUCCESSFUL; } ++curr; } } return PCIBIOS_DEVICE_NOT_FOUND; } /* * Functions for accessing PCI configuration space with type 1 accesses */ #define CONFIG_CMD(bus, device_fn, where) (0x80000000 | (bus << 16) | (device_fn << 8) | (where & ~3)) static int pci_conf1_read_config_byte(unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char *value) { unsigned long flags; save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); *value = inb(0xCFC + (where&3)); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf1_read_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short *value) { unsigned long flags; if (where&1) return PCIBIOS_BAD_REGISTER_NUMBER; save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); *value = inw(0xCFC + (where&2)); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf1_read_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int *value) { unsigned long flags; if (where&3) return PCIBIOS_BAD_REGISTER_NUMBER; save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); *value = inl(0xCFC); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf1_write_config_byte (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char value) { unsigned long flags; save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); outb(value, 0xCFC + (where&3)); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf1_write_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short value) { unsigned long flags; if (where&1) return PCIBIOS_BAD_REGISTER_NUMBER; save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); outw(value, 0xCFC + (where&2)); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf1_write_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int value) { unsigned long flags; if (where&3) return PCIBIOS_BAD_REGISTER_NUMBER; save_flags(flags); cli(); outl(CONFIG_CMD(bus,device_fn,where), 0xCF8); outl(value, 0xCFC); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } #undef CONFIG_CMD /* * functiontable for type 1 */ static struct pci_access pci_direct_conf1 = { pci_direct_find_device, pci_direct_find_class, pci_conf1_read_config_byte, pci_conf1_read_config_word, pci_conf1_read_config_dword, pci_conf1_write_config_byte, pci_conf1_write_config_word, pci_conf1_write_config_dword }; /* * Functions for accessing PCI configuration space with type 2 accesses */ #define IOADDR(devfn, where) ((0xC000 | ((devfn & 0x78) << 5)) + where) #define FUNC(devfn) (((devfn & 7) << 1) | 0xf0) static int pci_conf2_read_config_byte(unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char *value) { unsigned long flags; if (device_fn & 0x80) return PCIBIOS_DEVICE_NOT_FOUND; save_flags(flags); cli(); outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); *value = inb(IOADDR(device_fn,where)); outb (0, 0xCF8); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf2_read_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short *value) { unsigned long flags; if (device_fn & 0x80) return PCIBIOS_DEVICE_NOT_FOUND; save_flags(flags); cli(); outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); *value = inw(IOADDR(device_fn,where)); outb (0, 0xCF8); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf2_read_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int *value) { unsigned long flags; if (device_fn & 0x80) return PCIBIOS_DEVICE_NOT_FOUND; save_flags(flags); cli(); outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); *value = inl (IOADDR(device_fn,where)); outb (0, 0xCF8); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf2_write_config_byte (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char value) { unsigned long flags; save_flags(flags); cli(); outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); outb (value, IOADDR(device_fn,where)); outb (0, 0xCF8); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf2_write_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short value) { unsigned long flags; save_flags(flags); cli(); outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); outw (value, IOADDR(device_fn,where)); outb (0, 0xCF8); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } static int pci_conf2_write_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int value) { unsigned long flags; save_flags(flags); cli(); outb (FUNC(device_fn), 0xCF8); outb (bus, 0xCFA); outl (value, IOADDR(device_fn,where)); outb (0, 0xCF8); restore_flags(flags); return PCIBIOS_SUCCESSFUL; } #undef IOADDR #undef FUNC /* * functiontable for type 2 */ static struct pci_access pci_direct_conf2 = { pci_direct_find_device, pci_direct_find_class, pci_conf2_read_config_byte, pci_conf2_read_config_word, pci_conf2_read_config_dword, pci_conf2_write_config_byte, pci_conf2_write_config_word, pci_conf2_write_config_dword }; static struct pci_access *check_direct_pci(void) { unsigned int tmp; unsigned long flags; save_flags(flags); cli(); /* * check if configuration type 1 works */ outb (0x01, 0xCFB); tmp = inl (0xCF8); outl (0x80000000, 0xCF8); if (inl (0xCF8) == 0x80000000) { outl (tmp, 0xCF8); restore_flags(flags); printk("pcibios_init: Using configuration type 1\n"); return &pci_direct_conf1; } outl (tmp, 0xCF8); /* * check if configuration type 2 works */ outb (0x00, 0xCFB); outb (0x00, 0xCF8); outb (0x00, 0xCFA); if (inb (0xCF8) == 0x00 && inb (0xCFB) == 0x00) { restore_flags(flags); printk("pcibios_init: Using configuration type 2\n"); return &pci_direct_conf2; } restore_flags(flags); printk("pcibios_init: Not supported chipset for direct PCI access !\n"); return NULL; } /* * access defined pcibios functions via * the function table */ int pcibios_present(void) { return access_pci ? 1 : 0; } int pcibios_find_class (unsigned int class_code, unsigned short index, unsigned char *bus, unsigned char *device_fn) { if (access_pci && access_pci->find_class) return access_pci->find_class(class_code, index, bus, device_fn); return PCIBIOS_FUNC_NOT_SUPPORTED; } int pcibios_find_device (unsigned short vendor, unsigned short device_id, unsigned short index, unsigned char *bus, unsigned char *device_fn) { if (access_pci && access_pci->find_device) return access_pci->find_device(vendor, device_id, index, bus, device_fn); return PCIBIOS_FUNC_NOT_SUPPORTED; } int pcibios_read_config_byte (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char *value) { if (access_pci && access_pci->read_config_byte) return access_pci->read_config_byte(bus, device_fn, where, value); return PCIBIOS_FUNC_NOT_SUPPORTED; } int pcibios_read_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short *value) { if (access_pci && access_pci->read_config_word) return access_pci->read_config_word(bus, device_fn, where, value); return PCIBIOS_FUNC_NOT_SUPPORTED; } int pcibios_read_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int *value) { if (access_pci && access_pci->read_config_dword) return access_pci->read_config_dword(bus, device_fn, where, value); return PCIBIOS_FUNC_NOT_SUPPORTED; } int pcibios_write_config_byte (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned char value) { if (access_pci && access_pci->write_config_byte) return access_pci->write_config_byte(bus, device_fn, where, value); return PCIBIOS_FUNC_NOT_SUPPORTED; } int pcibios_write_config_word (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned short value) { if (access_pci && access_pci->write_config_word) return access_pci->write_config_word(bus, device_fn, where, value); return PCIBIOS_FUNC_NOT_SUPPORTED; } int pcibios_write_config_dword (unsigned char bus, unsigned char device_fn, unsigned char where, unsigned int value) { if (access_pci && access_pci->write_config_dword) return access_pci->write_config_dword(bus, device_fn, where, value); return PCIBIOS_FUNC_NOT_SUPPORTED; } const char *pcibios_strerror (int error) { static char buf[80]; switch (error) { case PCIBIOS_SUCCESSFUL: return "SUCCESSFUL"; case PCIBIOS_FUNC_NOT_SUPPORTED: return "FUNC_NOT_SUPPORTED"; case PCIBIOS_BAD_VENDOR_ID: return "SUCCESSFUL"; case PCIBIOS_DEVICE_NOT_FOUND: return "DEVICE_NOT_FOUND"; case PCIBIOS_BAD_REGISTER_NUMBER: return "BAD_REGISTER_NUMBER"; case PCIBIOS_SET_FAILED: return "SET_FAILED"; case PCIBIOS_BUFFER_TOO_SMALL: return "BUFFER_TOO_SMALL"; default: sprintf (buf, "UNKNOWN RETURN 0x%x", error); return buf; } } unsigned long pcibios_fixup(unsigned long mem_start, unsigned long mem_end) { return mem_start; } #endif unsigned long pcibios_init(unsigned long memory_start, unsigned long memory_end) { #ifdef CONFIG_PCI union bios32 *check; unsigned char sum; int i, length; /* * Follow the standard procedure for locating the BIOS32 Service * directory by scanning the permissible address range from * 0xe0000 through 0xfffff for a valid BIOS32 structure. * */ for (check = (union bios32 *) 0xe0000; check <= (union bios32 *) 0xffff0; ++check) { if (check->fields.signature != BIOS32_SIGNATURE) continue; length = check->fields.length * 16; if (!length) continue; sum = 0; for (i = 0; i < length ; ++i) sum += check->chars[i]; if (sum != 0) continue; if (check->fields.revision != 0) { printk("pcibios_init : unsupported revision %d at 0x%p, mail drew@colorado.edu\n", check->fields.revision, check); continue; } printk ("pcibios_init : BIOS32 Service Directory structure at 0x%p\n", check); if (!bios32_entry) { if (check->fields.entry >= 0x100000) { printk("pcibios_init: entry in high memory, trying direct PCI access\n"); access_pci = check_direct_pci(); } else { bios32_entry = check->fields.entry; printk ("pcibios_init : BIOS32 Service Directory entry at 0x%lx\n", bios32_entry); bios32_indirect.address = bios32_entry; } } } if (bios32_entry && check_pcibios()) access_pci = &pci_bios_access; #endif return memory_start; }