diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-23 21:45:09 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-23 21:45:09 (GMT) |
commit | 8c81f48e16fbe103e682d7ee7b2f16d065c42954 (patch) | |
tree | 1eac3abf36ed9330b3d5f9e550d1ccbc0c174f9b /arch | |
parent | 5de551e0eeddf470928e9fee59825a3645641bc7 (diff) | |
parent | 75b128573b275d5a5a7210b98c4b8cb3b39c12e7 (diff) | |
download | linux-8c81f48e16fbe103e682d7ee7b2f16d065c42954.tar.xz |
Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 EFI updates from Peter Anvin:
"This patchset falls under the "maintainers that grovel" clause in the
v3.18-rc1 announcement. We had intended to push it late in the merge
window since we got it into the -tip tree relatively late.
Many of these are relatively simple things, but there are a couple of
key bits, especially Ard's and Matt's patches"
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
rtc: Disable EFI rtc for x86
efi: rtc-efi: Export platform:rtc-efi as module alias
efi: Delete the in_nmi() conditional runtime locking
efi: Provide a non-blocking SetVariable() operation
x86/efi: Adding efi_printks on memory allocationa and pci.reads
x86/efi: Mark initialization code as such
x86/efi: Update comment regarding required phys mapped EFI services
x86/efi: Unexport add_efi_memmap variable
x86/efi: Remove unused efi_call* macros
efi: Resolve some shadow warnings
arm64: efi: Format EFI memory type & attrs with efi_md_typeattr_format()
ia64: efi: Format EFI memory type & attrs with efi_md_typeattr_format()
x86: efi: Format EFI memory type & attrs with efi_md_typeattr_format()
efi: Introduce efi_md_typeattr_format()
efi: Add macro for EFI_MEMORY_UCE memory attribute
x86/efi: Clear EFI_RUNTIME_SERVICES if failing to enter virtual mode
arm64/efi: Do not enter virtual mode if booting with efi=noruntime or noefi
arm64/efi: uefi_init error handling fix
efi: Add kernel param efi=noruntime
lib: Add a generic cmdline parse function parse_option_str
...
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm64/kernel/efi.c | 44 | ||||
-rw-r--r-- | arch/ia64/kernel/efi.c | 6 | ||||
-rw-r--r-- | arch/x86/boot/compressed/eboot.c | 32 | ||||
-rw-r--r-- | arch/x86/include/asm/efi.h | 31 | ||||
-rw-r--r-- | arch/x86/platform/efi/efi-bgrt.c | 36 | ||||
-rw-r--r-- | arch/x86/platform/efi/efi.c | 52 | ||||
-rw-r--r-- | arch/x86/platform/efi/efi_32.c | 12 | ||||
-rw-r--r-- | arch/x86/platform/efi/efi_64.c | 6 | ||||
-rw-r--r-- | arch/x86/platform/efi/efi_stub_32.S | 4 |
9 files changed, 122 insertions, 101 deletions
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 03aaa99..95c49eb 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -89,7 +89,8 @@ static int __init uefi_init(void) */ if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) { pr_err("System table signature incorrect\n"); - return -EINVAL; + retval = -EINVAL; + goto out; } if ((efi.systab->hdr.revision >> 16) < 2) pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n", @@ -103,6 +104,7 @@ static int __init uefi_init(void) for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i) vendor[i] = c16[i]; vendor[i] = '\0'; + early_memunmap(c16, sizeof(vendor)); } pr_info("EFI v%u.%.02u by %s\n", @@ -113,29 +115,11 @@ static int __init uefi_init(void) if (retval == 0) set_bit(EFI_CONFIG_TABLES, &efi.flags); - early_memunmap(c16, sizeof(vendor)); +out: early_memunmap(efi.systab, sizeof(efi_system_table_t)); - return retval; } -static __initdata char memory_type_name[][32] = { - {"Reserved"}, - {"Loader Code"}, - {"Loader Data"}, - {"Boot Code"}, - {"Boot Data"}, - {"Runtime Code"}, - {"Runtime Data"}, - {"Conventional Memory"}, - {"Unusable Memory"}, - {"ACPI Reclaim Memory"}, - {"ACPI Memory NVS"}, - {"Memory Mapped I/O"}, - {"MMIO Port Space"}, - {"PAL Code"}, -}; - /* * Return true for RAM regions we want to permanently reserve. */ @@ -166,10 +150,13 @@ static __init void reserve_regions(void) paddr = md->phys_addr; npages = md->num_pages; - if (uefi_debug) - pr_info(" 0x%012llx-0x%012llx [%s]", + if (uefi_debug) { + char buf[64]; + + pr_info(" 0x%012llx-0x%012llx %s", paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1, - memory_type_name[md->type]); + efi_md_typeattr_format(buf, sizeof(buf), md)); + } memrange_efi_to_native(&paddr, &npages); size = npages << PAGE_SHIFT; @@ -393,11 +380,16 @@ static int __init arm64_enter_virtual_mode(void) return -1; } - pr_info("Remapping and enabling EFI services.\n"); - - /* replace early memmap mapping with permanent mapping */ mapsize = memmap.map_end - memmap.map; early_memunmap(memmap.map, mapsize); + + if (efi_runtime_disabled()) { + pr_info("EFI runtime services will be disabled.\n"); + return -1; + } + + pr_info("Remapping and enabling EFI services.\n"); + /* replace early memmap mapping with permanent mapping */ memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map, mapsize); memmap.map_end = memmap.map + mapsize; diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c index 741b99c..c52d754 100644 --- a/arch/ia64/kernel/efi.c +++ b/arch/ia64/kernel/efi.c @@ -568,6 +568,7 @@ efi_init (void) { const char *unit; unsigned long size; + char buf[64]; md = p; size = md->num_pages << EFI_PAGE_SHIFT; @@ -586,9 +587,10 @@ efi_init (void) unit = "KB"; } - printk("mem%02d: type=%2u, attr=0x%016lx, " + printk("mem%02d: %s " "range=[0x%016lx-0x%016lx) (%4lu%s)\n", - i, md->type, md->attribute, md->phys_addr, + i, efi_md_typeattr_format(buf, sizeof(buf), md), + md->phys_addr, md->phys_addr + efi_md_size(md), size, unit); } } diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index de8eebd..1acf605 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -330,8 +330,10 @@ __setup_efi_pci32(efi_pci_io_protocol_32 *pci, struct pci_setup_rom **__rom) size = pci->romsize + sizeof(*rom); status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom); - if (status != EFI_SUCCESS) + if (status != EFI_SUCCESS) { + efi_printk(sys_table, "Failed to alloc mem for rom\n"); return status; + } memset(rom, 0, sizeof(*rom)); @@ -344,14 +346,18 @@ __setup_efi_pci32(efi_pci_io_protocol_32 *pci, struct pci_setup_rom **__rom) status = efi_early->call(pci->pci.read, pci, EfiPciIoWidthUint16, PCI_VENDOR_ID, 1, &(rom->vendor)); - if (status != EFI_SUCCESS) + if (status != EFI_SUCCESS) { + efi_printk(sys_table, "Failed to read rom->vendor\n"); goto free_struct; + } status = efi_early->call(pci->pci.read, pci, EfiPciIoWidthUint16, PCI_DEVICE_ID, 1, &(rom->devid)); - if (status != EFI_SUCCESS) + if (status != EFI_SUCCESS) { + efi_printk(sys_table, "Failed to read rom->devid\n"); goto free_struct; + } status = efi_early->call(pci->get_location, pci, &(rom->segment), &(rom->bus), &(rom->device), &(rom->function)); @@ -432,8 +438,10 @@ __setup_efi_pci64(efi_pci_io_protocol_64 *pci, struct pci_setup_rom **__rom) size = pci->romsize + sizeof(*rom); status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom); - if (status != EFI_SUCCESS) + if (status != EFI_SUCCESS) { + efi_printk(sys_table, "Failed to alloc mem for rom\n"); return status; + } rom->data.type = SETUP_PCI; rom->data.len = size - sizeof(struct setup_data); @@ -444,14 +452,18 @@ __setup_efi_pci64(efi_pci_io_protocol_64 *pci, struct pci_setup_rom **__rom) status = efi_early->call(pci->pci.read, pci, EfiPciIoWidthUint16, PCI_VENDOR_ID, 1, &(rom->vendor)); - if (status != EFI_SUCCESS) + if (status != EFI_SUCCESS) { + efi_printk(sys_table, "Failed to read rom->vendor\n"); goto free_struct; + } status = efi_early->call(pci->pci.read, pci, EfiPciIoWidthUint16, PCI_DEVICE_ID, 1, &(rom->devid)); - if (status != EFI_SUCCESS) + if (status != EFI_SUCCESS) { + efi_printk(sys_table, "Failed to read rom->devid\n"); goto free_struct; + } status = efi_early->call(pci->get_location, pci, &(rom->segment), &(rom->bus), &(rom->device), &(rom->function)); @@ -538,8 +550,10 @@ static void setup_efi_pci(struct boot_params *params) EFI_LOADER_DATA, size, (void **)&pci_handle); - if (status != EFI_SUCCESS) + if (status != EFI_SUCCESS) { + efi_printk(sys_table, "Failed to alloc mem for pci_handle\n"); return; + } status = efi_call_early(locate_handle, EFI_LOCATE_BY_PROTOCOL, &pci_proto, @@ -1105,6 +1119,10 @@ struct boot_params *make_boot_params(struct efi_config *c) memset(sdt, 0, sizeof(*sdt)); + status = efi_parse_options(cmdline_ptr); + if (status != EFI_SUCCESS) + goto fail2; + status = handle_cmdline_files(sys_table, image, (char *)(unsigned long)hdr->cmd_line_ptr, "initrd=", hdr->initrd_addr_max, diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 0ec241e..9b11757 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -81,24 +81,23 @@ extern u64 asmlinkage efi_call(void *fp, ...); */ #define __efi_call_virt(f, args...) efi_call_virt(f, args) -extern void __iomem *efi_ioremap(unsigned long addr, unsigned long size, - u32 type, u64 attribute); +extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size, + u32 type, u64 attribute); #endif /* CONFIG_X86_32 */ -extern int add_efi_memmap; extern struct efi_scratch efi_scratch; -extern void efi_set_executable(efi_memory_desc_t *md, bool executable); -extern int efi_memblock_x86_reserve_range(void); -extern void efi_call_phys_prelog(void); -extern void efi_call_phys_epilog(void); -extern void efi_unmap_memmap(void); -extern void efi_memory_uc(u64 addr, unsigned long size); +extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable); +extern int __init efi_memblock_x86_reserve_range(void); +extern void __init efi_call_phys_prolog(void); +extern void __init efi_call_phys_epilog(void); +extern void __init efi_unmap_memmap(void); +extern void __init efi_memory_uc(u64 addr, unsigned long size); extern void __init efi_map_region(efi_memory_desc_t *md); extern void __init efi_map_region_fixed(efi_memory_desc_t *md); extern void efi_sync_low_kernel_mappings(void); -extern int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages); -extern void efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages); +extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages); +extern void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages); extern void __init old_map_region(efi_memory_desc_t *md); extern void __init runtime_code_page_mkexec(void); extern void __init efi_runtime_mkexec(void); @@ -162,16 +161,6 @@ static inline efi_status_t efi_thunk_set_virtual_address_map( extern bool efi_reboot_required(void); #else -/* - * IF EFI is not configured, have the EFI calls return -ENOSYS. - */ -#define efi_call0(_f) (-ENOSYS) -#define efi_call1(_f, _a1) (-ENOSYS) -#define efi_call2(_f, _a1, _a2) (-ENOSYS) -#define efi_call3(_f, _a1, _a2, _a3) (-ENOSYS) -#define efi_call4(_f, _a1, _a2, _a3, _a4) (-ENOSYS) -#define efi_call5(_f, _a1, _a2, _a3, _a4, _a5) (-ENOSYS) -#define efi_call6(_f, _a1, _a2, _a3, _a4, _a5, _a6) (-ENOSYS) static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {} static inline bool efi_reboot_required(void) { diff --git a/arch/x86/platform/efi/efi-bgrt.c b/arch/x86/platform/efi/efi-bgrt.c index f15103d..d143d21 100644 --- a/arch/x86/platform/efi/efi-bgrt.c +++ b/arch/x86/platform/efi/efi-bgrt.c @@ -40,20 +40,40 @@ void __init efi_bgrt_init(void) if (ACPI_FAILURE(status)) return; - if (bgrt_tab->header.length < sizeof(*bgrt_tab)) + if (bgrt_tab->header.length < sizeof(*bgrt_tab)) { + pr_err("Ignoring BGRT: invalid length %u (expected %zu)\n", + bgrt_tab->header.length, sizeof(*bgrt_tab)); return; - if (bgrt_tab->version != 1 || bgrt_tab->status != 1) + } + if (bgrt_tab->version != 1) { + pr_err("Ignoring BGRT: invalid version %u (expected 1)\n", + bgrt_tab->version); + return; + } + if (bgrt_tab->status != 1) { + pr_err("Ignoring BGRT: invalid status %u (expected 1)\n", + bgrt_tab->status); + return; + } + if (bgrt_tab->image_type != 0) { + pr_err("Ignoring BGRT: invalid image type %u (expected 0)\n", + bgrt_tab->image_type); return; - if (bgrt_tab->image_type != 0 || !bgrt_tab->image_address) + } + if (!bgrt_tab->image_address) { + pr_err("Ignoring BGRT: null image address\n"); return; + } image = efi_lookup_mapped_addr(bgrt_tab->image_address); if (!image) { image = early_memremap(bgrt_tab->image_address, sizeof(bmp_header)); ioremapped = true; - if (!image) + if (!image) { + pr_err("Ignoring BGRT: failed to map image header memory\n"); return; + } } memcpy_fromio(&bmp_header, image, sizeof(bmp_header)); @@ -61,14 +81,18 @@ void __init efi_bgrt_init(void) early_iounmap(image, sizeof(bmp_header)); bgrt_image_size = bmp_header.size; - bgrt_image = kmalloc(bgrt_image_size, GFP_KERNEL); - if (!bgrt_image) + bgrt_image = kmalloc(bgrt_image_size, GFP_KERNEL | __GFP_NOWARN); + if (!bgrt_image) { + pr_err("Ignoring BGRT: failed to allocate memory for image (wanted %zu bytes)\n", + bgrt_image_size); return; + } if (ioremapped) { image = early_memremap(bgrt_tab->image_address, bmp_header.size); if (!image) { + pr_err("Ignoring BGRT: failed to map image memory\n"); kfree(bgrt_image); bgrt_image = NULL; return; diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 850da94..dbc8627 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -70,17 +70,7 @@ static efi_config_table_type_t arch_tables[] __initdata = { u64 efi_setup; /* efi setup_data physical address */ -static bool disable_runtime __initdata = false; -static int __init setup_noefi(char *arg) -{ - disable_runtime = true; - return 0; -} -early_param("noefi", setup_noefi); - -int add_efi_memmap; -EXPORT_SYMBOL(add_efi_memmap); - +static int add_efi_memmap __initdata; static int __init setup_add_efi_memmap(char *arg) { add_efi_memmap = 1; @@ -96,7 +86,7 @@ static efi_status_t __init phys_efi_set_virtual_address_map( { efi_status_t status; - efi_call_phys_prelog(); + efi_call_phys_prolog(); status = efi_call_phys(efi_phys.set_virtual_address_map, memory_map_size, descriptor_size, descriptor_version, virtual_map); @@ -210,9 +200,12 @@ static void __init print_efi_memmap(void) for (p = memmap.map, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) { + char buf[64]; + md = p; - pr_info("mem%02u: type=%u, attr=0x%llx, range=[0x%016llx-0x%016llx) (%lluMB)\n", - i, md->type, md->attribute, md->phys_addr, + pr_info("mem%02u: %s range=[0x%016llx-0x%016llx) (%lluMB)\n", + i, efi_md_typeattr_format(buf, sizeof(buf), md), + md->phys_addr, md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT), (md->num_pages >> (20 - EFI_PAGE_SHIFT))); } @@ -344,9 +337,9 @@ static int __init efi_runtime_init32(void) } /* - * We will only need *early* access to the following two - * EFI runtime services before set_virtual_address_map - * is invoked. + * We will only need *early* access to the SetVirtualAddressMap + * EFI runtime service. All other runtime services will be called + * via the virtual mapping. */ efi_phys.set_virtual_address_map = (efi_set_virtual_address_map_t *) @@ -368,9 +361,9 @@ static int __init efi_runtime_init64(void) } /* - * We will only need *early* access to the following two - * EFI runtime services before set_virtual_address_map - * is invoked. + * We will only need *early* access to the SetVirtualAddressMap + * EFI runtime service. All other runtime services will be called + * via the virtual mapping. */ efi_phys.set_virtual_address_map = (efi_set_virtual_address_map_t *) @@ -492,7 +485,7 @@ void __init efi_init(void) if (!efi_runtime_supported()) pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n"); else { - if (disable_runtime || efi_runtime_init()) + if (efi_runtime_disabled() || efi_runtime_init()) return; } if (efi_memmap_init()) @@ -537,7 +530,7 @@ void __init runtime_code_page_mkexec(void) } } -void efi_memory_uc(u64 addr, unsigned long size) +void __init efi_memory_uc(u64 addr, unsigned long size) { unsigned long page_shift = 1UL << EFI_PAGE_SHIFT; u64 npages; @@ -732,6 +725,7 @@ static void __init kexec_enter_virtual_mode(void) */ if (!efi_is_native()) { efi_unmap_memmap(); + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); return; } @@ -805,6 +799,7 @@ static void __init __efi_enter_virtual_mode(void) new_memmap = efi_map_regions(&count, &pg_shift); if (!new_memmap) { pr_err("Error reallocating memory, EFI runtime non-functional!\n"); + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); return; } @@ -812,8 +807,10 @@ static void __init __efi_enter_virtual_mode(void) BUG_ON(!efi.systab); - if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) + if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) { + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); return; + } efi_sync_low_kernel_mappings(); efi_dump_pagetable(); @@ -938,14 +935,11 @@ u64 efi_mem_attributes(unsigned long phys_addr) return 0; } -static int __init parse_efi_cmdline(char *str) +static int __init arch_parse_efi_cmdline(char *str) { - if (*str == '=') - str++; - - if (!strncmp(str, "old_map", 7)) + if (parse_option_str(str, "old_map")) set_bit(EFI_OLD_MEMMAP, &efi.flags); return 0; } -early_param("efi", parse_efi_cmdline); +early_param("efi", arch_parse_efi_cmdline); diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c index 9ee3491..40e7cda 100644 --- a/arch/x86/platform/efi/efi_32.c +++ b/arch/x86/platform/efi/efi_32.c @@ -33,7 +33,7 @@ /* * To make EFI call EFI runtime service in physical addressing mode we need - * prelog/epilog before/after the invocation to disable interrupt, to + * prolog/epilog before/after the invocation to disable interrupt, to * claim EFI runtime service handler exclusively and to duplicate a memory in * low memory space say 0 - 3G. */ @@ -41,11 +41,13 @@ static unsigned long efi_rt_eflags; void efi_sync_low_kernel_mappings(void) {} void __init efi_dump_pagetable(void) {} -int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) +int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) { return 0; } -void efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages) {} +void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages) +{ +} void __init efi_map_region(efi_memory_desc_t *md) { @@ -55,7 +57,7 @@ void __init efi_map_region(efi_memory_desc_t *md) void __init efi_map_region_fixed(efi_memory_desc_t *md) {} void __init parse_efi_setup(u64 phys_addr, u32 data_len) {} -void efi_call_phys_prelog(void) +void __init efi_call_phys_prolog(void) { struct desc_ptr gdt_descr; @@ -69,7 +71,7 @@ void efi_call_phys_prelog(void) load_gdt(&gdt_descr); } -void efi_call_phys_epilog(void) +void __init efi_call_phys_epilog(void) { struct desc_ptr gdt_descr; diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 290d397..35aecb6 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -79,7 +79,7 @@ static void __init early_code_mapping_set_exec(int executable) } } -void __init efi_call_phys_prelog(void) +void __init efi_call_phys_prolog(void) { unsigned long vaddress; int pgd; @@ -139,7 +139,7 @@ void efi_sync_low_kernel_mappings(void) sizeof(pgd_t) * num_pgds); } -int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) +int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) { unsigned long text; struct page *page; @@ -192,7 +192,7 @@ int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) return 0; } -void efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages) +void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages) { pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd); diff --git a/arch/x86/platform/efi/efi_stub_32.S b/arch/x86/platform/efi/efi_stub_32.S index fbe66e6..040192b 100644 --- a/arch/x86/platform/efi/efi_stub_32.S +++ b/arch/x86/platform/efi/efi_stub_32.S @@ -27,13 +27,13 @@ ENTRY(efi_call_phys) * set to 0x0010, DS and SS have been set to 0x0018. In EFI, I found * the values of these registers are the same. And, the corresponding * GDT entries are identical. So I will do nothing about segment reg - * and GDT, but change GDT base register in prelog and epilog. + * and GDT, but change GDT base register in prolog and epilog. */ /* * 1. Now I am running with EIP = <physical address> + PAGE_OFFSET. * But to make it smoothly switch from virtual mode to flat mode. - * The mapping of lower virtual memory has been created in prelog and + * The mapping of lower virtual memory has been created in prolog and * epilog. */ movl $1f, %edx |