diff options
| -rw-r--r-- | lib/ecam.c | 36 |
1 files changed, 27 insertions, 9 deletions
@@ -221,9 +221,11 @@ find_rsdp_address(struct pci_access *a, const char *efisystab, int use_bsd UNUSE #if defined(__amd64__) || defined(__i386__) struct ecam_access *eacc = a->backend_data; struct physmem *physmem = eacc->physmem; + long pagesize = eacc->pagesize; u64 rsdp_addr; u64 addr; void *map; + u64 ebda; #endif size_t len; FILE *f; @@ -305,23 +307,39 @@ find_rsdp_address(struct pci_access *a, const char *efisystab, int use_bsd UNUSE rsdp_addr = 0; /* Scan first kB of Extended BIOS Data Area */ - a->debug("scanning first kB of EBDA..."); - map = physmem_map(physmem, 0, 0x40E + 1024, 0); + a->debug("reading EBDA location from BDA..."); + map = physmem_map(physmem, 0, 0x40E + 2, 0); if (map != (void *)-1) { - for (addr = 0x40E; addr < 0x40E + 1024; addr += 16) + ebda = (u64)physmem_readw((unsigned char *)map + 0x40E) << 4; + if (physmem_unmap(physmem, map, 0x40E + 2) != 0) + a->debug("unmapping of BDA failed: %s...", strerror(errno)); + if (ebda >= 0x400) { - if (check_rsdp((struct acpi_rsdp *)((unsigned char *)map + addr))) + a->debug("scanning first kB of EBDA at 0x%" PCI_U64_FMT_X "...", ebda); + map = physmem_map(physmem, ebda & ~(pagesize-1), 1024 + (ebda & (pagesize-1)), 0); + if (map != (void *)-1) { - rsdp_addr = addr; - break; + for (addr = ebda & (pagesize-1); addr < (ebda & (pagesize-1)) + 1024; addr += 16) + { + if (check_rsdp((struct acpi_rsdp *)((unsigned char *)map + addr))) + { + rsdp_addr = (ebda & ~(pagesize-1)) + addr; + break; + } + } + if (physmem_unmap(physmem, map, 1024 + (ebda & (pagesize-1))) != 0) + a->debug("unmapping of EBDA failed: %s...", strerror(errno)); } + else + a->debug("mapping of EBDA failed: %s...", strerror(errno)); } - if (physmem_unmap(physmem, map, 0x40E + 1024) != 0) - a->debug("unmapping of EBDA failed: %s...", strerror(errno)); + else + a->debug("EBDA location 0x%" PCI_U64_FMT_X " is insane...", ebda); } else - a->debug("mapping of EBDA failed: %s...", strerror(errno)); + a->debug("mapping of BDA failed: %s...", strerror(errno)); + if (rsdp_addr) return rsdp_addr; |