[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v9 07/13] x86: add multiboot2 protocol support for EFI platforms
This way Xen can be loaded on EFI platforms using GRUB2 and other boot loaders which support multiboot2 protocol. Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx> --- v9 - suggestions/fixes: - use .L labels instead of numeric ones in multiboot2 data scanning loops (suggested by Jan Beulich). v8 - suggestions/fixes: - use __bss_start(%rip)/__bss_end(%rip) instead of of .startof.(.bss)(%rip)/$.sizeof.(.bss) because latter is not tested extensively in different built environments yet (suggested by Andrew Cooper), - fix multiboot2 data scanning loop in x86_32 code (suggested by Jan Beulich), - add check for extra mem for mbi data if Xen is loaded via multiboot2 protocol on EFI platform (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich). v7 - suggestions/fixes: - do not allocate twice memory for trampoline if we were loaded via multiboot2 protocol on EFI platform, - wrap long line (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich). v6 - suggestions/fixes: - improve label names in assembly error printing code (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich), - various minor cleanups and fixes (suggested by Jan Beulich). v4 - suggestions/fixes: - remove redundant BSS alignment, - update BSS alignment check, - use __set_bit() instead of set_bit() if possible (suggested by Jan Beulich), - call efi_arch_cpu() from efi_multiboot2() even if the same work is done later in other place right now (suggested by Jan Beulich), - xen/arch/x86/efi/stub.c:efi_multiboot2() fail properly on EFI platforms, - do not read data beyond the end of multiboot2 information in xen/arch/x86/boot/head.S (suggested by Jan Beulich), - use 32-bit registers in x86_64 code if possible (suggested by Jan Beulich), - multiboot2 information address is 64-bit in x86_64 code, so, treat it is as is (suggested by Jan Beulich), - use cmovcc if possible, - leave only one space between rep and stosq (suggested by Jan Beulich), - improve error handling, - improve early error messages, (suggested by Jan Beulich), - improve early error messages printing code, - improve label names (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich), - various minor cleanups. v3 - suggestions/fixes: - take into account alignment when skipping multiboot2 fixed part (suggested by Konrad Rzeszutek Wilk), - improve segment registers initialization (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich and Konrad Rzeszutek Wilk), - improve commit message (suggested by Jan Beulich). v2 - suggestions/fixes: - generate multiboot2 header using macros (suggested by Jan Beulich), - switch CPU to x86_32 mode before jumping to 32-bit code (suggested by Andrew Cooper), - reduce code changes to increase patch readability (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich), - ignore MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO tag on EFI platform and find on my own multiboot2.mem_lower value, - stop execution if EFI platform is detected in legacy BIOS path. --- xen/arch/x86/boot/head.S | 260 ++++++++++++++++++++++++++++++++++--- xen/arch/x86/efi/efi-boot.h | 54 +++++++- xen/arch/x86/efi/stub.c | 38 ++++++ xen/arch/x86/x86_64/asm-offsets.c | 2 + xen/arch/x86/xen.lds.S | 4 +- xen/common/efi/boot.c | 11 ++ 6 files changed, 346 insertions(+), 23 deletions(-) diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S index d423fd8..0155b32 100644 --- a/xen/arch/x86/boot/head.S +++ b/xen/arch/x86/boot/head.S @@ -89,6 +89,13 @@ multiboot2_header_start: 0, /* Number of the lines - no preference. */ \ 0 /* Number of bits per pixel - no preference. */ + /* Inhibit bootloader from calling ExitBootServices(). */ + mb2ht_init MB2_HT(EFI_BS), MB2_HT(OPTIONAL) + + /* EFI64 entry point. */ + mb2ht_init MB2_HT(ENTRY_ADDRESS_EFI64), MB2_HT(OPTIONAL), \ + sym_phys(__efi64_start) + /* Multiboot2 header end tag. */ mb2ht_init MB2_HT(END), MB2_HT(REQUIRED) .Lmultiboot2_header_end: @@ -100,20 +107,49 @@ multiboot2_header_start: gdt_boot_descr: .word 6*8-1 .long sym_phys(trampoline_gdt) + .long 0 /* Needed for 64-bit lgdt */ + +cs32_switch_addr: + .long sym_phys(cs32_switch) + .word BOOT_CS32 + + .align 4 +vga_text_buffer: + .long 0xb8000 .Lbad_cpu_msg: .asciz "ERR: Not a 64-bit CPU!" .Lbad_ldr_msg: .asciz "ERR: Not a Multiboot bootloader!" +.Lbad_ldr_nbs: .asciz "ERR: Bootloader shutdown EFI x64 boot services!" +.Lbad_ldr_nst: .asciz "ERR: EFI SystemTable is not provided by bootloader!" +.Lbad_ldr_nih: .asciz "ERR: EFI ImageHandle is not provided by bootloader!" +.Lbad_efi_msg: .asciz "ERR: EFI IA-32 platforms are not supported!" .section .init.text, "ax", @progbits bad_cpu: mov $(sym_phys(.Lbad_cpu_msg)),%esi # Error message - jmp print_err + jmp .Lget_vtb not_multiboot: mov $(sym_phys(.Lbad_ldr_msg)),%esi # Error message -print_err: - mov $0xB8000,%edi # VGA framebuffer -1: mov (%esi),%bl + jmp .Lget_vtb +.Lmb2_no_st: + mov $(sym_phys(.Lbad_ldr_nst)),%esi # Error message + jmp .Lget_vtb +.Lmb2_no_ih: + mov $(sym_phys(.Lbad_ldr_nih)),%esi # Error message + jmp .Lget_vtb +.Lmb2_no_bs: + mov $(sym_phys(.Lbad_ldr_nbs)),%esi # Error message + xor %edi,%edi # No VGA text buffer + jmp .Lsend_chr +.Lmb2_efi_ia_32: + mov $(sym_phys(.Lbad_efi_msg)),%esi # Error message + xor %edi,%edi # No VGA text buffer + jmp .Lsend_chr +.Lget_vtb: + mov sym_phys(vga_text_buffer),%edi +.Lsend_chr: + mov (%esi),%bl test %bl,%bl # Terminate on '\0' sentinel je .Lhalt mov $0x3f8+5,%dx # UART Line Status Register @@ -123,13 +159,182 @@ print_err: mov $0x3f8+0,%dx # UART Transmit Holding Register mov %bl,%al out %al,%dx # Send a character over the serial line - movsb # Write a character to the VGA framebuffer + test %edi,%edi # Is the VGA text buffer available? + jz .Lsend_chr + movsb # Write a character to the VGA text buffer mov $7,%al - stosb # Write an attribute to the VGA framebuffer - jmp 1b + stosb # Write an attribute to the VGA text buffer + jmp .Lsend_chr .Lhalt: hlt jmp .Lhalt + .code64 + +__efi64_start: + cld + + /* VGA is not available on EFI platforms. */ + movl $0,vga_text_buffer(%rip) + + /* Check for Multiboot2 bootloader. */ + cmp $MULTIBOOT2_BOOTLOADER_MAGIC,%eax + je .Lefi_multiboot2_proto + + /* Jump to not_multiboot after switching CPU to x86_32 mode. */ + lea not_multiboot(%rip),%edi + jmp x86_32_switch + +.Lefi_multiboot2_proto: + /* Zero EFI SystemTable and EFI ImageHandle addresses. */ + xor %esi,%esi + xor %edi,%edi + + /* Skip Multiboot2 information fixed part. */ + lea (MB2_fixed_sizeof+MULTIBOOT2_TAG_ALIGN-1)(%rbx),%ecx + and $~(MULTIBOOT2_TAG_ALIGN-1),%ecx + +.Lefi_mb2_tsize: + /* Check Multiboot2 information total size. */ + mov %ecx,%r8d + sub %ebx,%r8d + cmp %r8d,MB2_fixed_total_size(%rbx) + jbe run_bs + + /* Are EFI boot services available? */ + cmpl $MULTIBOOT2_TAG_TYPE_EFI_BS,MB2_tag_type(%rcx) + jne .Lefi_mb2_st + + /* + * Yes, store that info in skip_realmode variable. I agree that + * its name is a bit unfortunate in this context, however, by the + * way we disable real mode and other legacy stuff which should + * not be run on EFI platforms. + */ + incb skip_realmode(%rip) + jmp .Lefi_mb2_next_tag + +.Lefi_mb2_st: + /* Get EFI SystemTable address from Multiboot2 information. */ + cmpl $MULTIBOOT2_TAG_TYPE_EFI64,MB2_tag_type(%rcx) + cmove MB2_efi64_st(%rcx),%rsi + je .Lefi_mb2_next_tag + + /* Get EFI ImageHandle address from Multiboot2 information. */ + cmpl $MULTIBOOT2_TAG_TYPE_EFI64_IH,MB2_tag_type(%rcx) + cmove MB2_efi64_ih(%rcx),%rdi + je .Lefi_mb2_next_tag + + /* Is it the end of Multiboot2 information? */ + cmpl $MULTIBOOT2_TAG_TYPE_END,MB2_tag_type(%rcx) + je run_bs + +.Lefi_mb2_next_tag: + /* Go to next Multiboot2 information tag. */ + add MB2_tag_size(%rcx),%ecx + add $(MULTIBOOT2_TAG_ALIGN-1),%ecx + and $~(MULTIBOOT2_TAG_ALIGN-1),%ecx + jmp .Lefi_mb2_tsize + +run_bs: + /* Are EFI boot services available? */ + cmpb $0,skip_realmode(%rip) + jnz 0f + + /* Jump to .Lmb2_no_bs after switching CPU to x86_32 mode. */ + lea .Lmb2_no_bs(%rip),%edi + jmp x86_32_switch + +0: + /* Is EFI SystemTable address provided by boot loader? */ + test %rsi,%rsi + jnz 1f + + /* Jump to .Lmb2_no_st after switching CPU to x86_32 mode. */ + lea .Lmb2_no_st(%rip),%edi + jmp x86_32_switch + +1: + /* Is EFI ImageHandle address provided by boot loader? */ + test %rdi,%rdi + jnz 2f + + /* Jump to .Lmb2_no_ih after switching CPU to x86_32 mode. */ + lea .Lmb2_no_ih(%rip),%edi + jmp x86_32_switch + +2: + push %rax + push %rdi + + /* + * Initialize BSS (no nasty surprises!). + * It must be done earlier than in BIOS case + * because efi_multiboot2() touches it. + */ + lea __bss_start(%rip),%edi + lea __bss_end(%rip),%ecx + sub %edi,%ecx + shr $3,%ecx + xor %eax,%eax + rep stosq + + pop %rdi + + /* + * efi_multiboot2() is called according to System V AMD64 ABI: + * - IN: %rdi - EFI ImageHandle, %rsi - EFI SystemTable, + * - OUT: %rax - highest usable memory address below 1 MiB; + * memory above this address is reserved for trampoline; + * memory below this address is used as a storage for + * mbi struct created in reloc(). + * + * MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO tag is not provided + * on EFI platforms. Hence, it could not be used like + * on legacy BIOS platforms. + */ + call efi_multiboot2 + + /* Convert memory address to bytes/16 and store it in safe place. */ + shr $4,%eax + mov %eax,%ecx + + pop %rax + + /* Jump to trampoline_setup after switching CPU to x86_32 mode. */ + lea trampoline_setup(%rip),%edi + +x86_32_switch: + cli + + /* Initialize GDTR. */ + lgdt gdt_boot_descr(%rip) + + /* Reload code selector. */ + ljmpl *cs32_switch_addr(%rip) + + .code32 + +cs32_switch: + /* Initialize basic data segments. */ + mov $BOOT_DS,%edx + mov %edx,%ds + mov %edx,%es + mov %edx,%ss + /* %esp is initialized later. */ + + /* Load null descriptor to unused segment registers. */ + xor %edx,%edx + mov %edx,%fs + mov %edx,%gs + + /* Disable paging. */ + mov %cr0,%edx + and $(~X86_CR0_PG),%edx + mov %edx,%cr0 + + /* Jump to earlier loaded address. */ + jmp *%edi + __start: cld cli @@ -157,7 +362,7 @@ __start: /* Not available? BDA value will be fine. */ cmovnz MB_mem_lower(%ebx),%edx - jmp trampoline_setup + jmp trampoline_bios_setup .Lmultiboot2_proto: /* Skip Multiboot2 information fixed part. */ @@ -169,24 +374,33 @@ __start: mov %ecx,%edi sub %ebx,%edi cmp %edi,MB2_fixed_total_size(%ebx) - jbe trampoline_setup + jbe trampoline_bios_setup /* Get mem_lower from Multiboot2 information. */ cmpl $MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO,MB2_tag_type(%ecx) cmove MB2_mem_lower(%ecx),%edx - je trampoline_setup + je .Lmb2_next_tag + + /* EFI IA-32 platforms are not supported. */ + cmpl $MULTIBOOT2_TAG_TYPE_EFI32,MB2_tag_type(%ecx) + je .Lmb2_efi_ia_32 + + /* Bootloader shutdown EFI x64 boot services. */ + cmpl $MULTIBOOT2_TAG_TYPE_EFI64,MB2_tag_type(%ecx) + je .Lmb2_no_bs /* Is it the end of Multiboot2 information? */ cmpl $MULTIBOOT2_TAG_TYPE_END,MB2_tag_type(%ecx) - je trampoline_setup + je trampoline_bios_setup +.Lmb2_next_tag: /* Go to next Multiboot2 information tag. */ add MB2_tag_size(%ecx),%ecx add $(MULTIBOOT2_TAG_ALIGN-1),%ecx and $~(MULTIBOOT2_TAG_ALIGN-1),%ecx jmp .Lmb2_tsize -trampoline_setup: +trampoline_bios_setup: /* Set up trampoline segment 64k below EBDA */ movzwl 0x40e,%ecx /* EBDA segment */ cmp $0xa000,%ecx /* sanity check (high) */ @@ -202,16 +416,19 @@ trampoline_setup: * multiboot structure (if available) and use the smallest. */ cmp $0x100,%edx /* is the multiboot value too small? */ - jb 2f /* if so, do not use it */ + jb trampoline_setup /* if so, do not use it */ shl $10-4,%edx cmp %ecx,%edx /* compare with BDA value */ cmovb %edx,%ecx /* and use the smaller */ -2: /* Reserve 64kb for the trampoline */ + /* Reserve 64kb for the trampoline. */ sub $0x1000,%ecx /* From arch/x86/smpboot.c: start_eip had better be page-aligned! */ xor %cl, %cl + +trampoline_setup: + /* Save trampoline address for later use. */ shl $4, %ecx mov %ecx,sym_phys(trampoline_phys) @@ -223,7 +440,14 @@ trampoline_setup: call reloc mov %eax,sym_phys(multiboot_ptr) - /* Initialize BSS (no nasty surprises!) */ + /* + * Do not zero BSS on EFI platform here. + * It was initialized earlier. + */ + cmpb $0,sym_phys(skip_realmode) + jnz 1f + + /* Initialize BSS (no nasty surprises!). */ mov $sym_phys(__bss_start),%edi mov $sym_phys(__bss_end),%ecx sub %edi,%ecx @@ -231,6 +455,7 @@ trampoline_setup: shr $2,%ecx rep stosl +1: /* Interrogate CPU extended features via CPUID. */ mov $0x80000000,%eax cpuid @@ -282,8 +507,13 @@ trampoline_setup: cmp $sym_phys(__trampoline_seg_stop),%edi jb 1b + /* Do not parse command line on EFI platform here. */ + cmpb $0,sym_phys(skip_realmode) + jnz 1f + call cmdline_parse_early +1: /* Switch to low-memory stack. */ mov sym_phys(trampoline_phys),%edi lea 0x10000(%edi),%esp diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h index 62c010e..dc857d8 100644 --- a/xen/arch/x86/efi/efi-boot.h +++ b/xen/arch/x86/efi/efi-boot.h @@ -146,6 +146,8 @@ static void __init efi_arch_process_memory_map(EFI_SYSTEM_TABLE *SystemTable, { struct e820entry *e; unsigned int i; + /* Check for extra mem for mbi data if Xen is loaded via multiboot2 protocol. */ + UINTN extra_mem = efi_enabled(EFI_LOADER) ? 0 : (64 << 10); /* Populate E820 table and check trampoline area availability. */ e = e820map - 1; @@ -168,7 +170,8 @@ static void __init efi_arch_process_memory_map(EFI_SYSTEM_TABLE *SystemTable, /* fall through */ case EfiConventionalMemory: if ( !trampoline_phys && desc->PhysicalStart + len <= 0x100000 && - len >= cfg.size && desc->PhysicalStart + len > cfg.addr ) + len >= cfg.size + extra_mem && + desc->PhysicalStart + len > cfg.addr ) cfg.addr = (desc->PhysicalStart + len - cfg.size) & PAGE_MASK; /* fall through */ case EfiLoaderCode: @@ -210,12 +213,14 @@ static void *__init efi_arch_allocate_mmap_buffer(UINTN map_size) static void __init efi_arch_pre_exit_boot(void) { - if ( !trampoline_phys ) - { - if ( !cfg.addr ) - blexit(L"No memory for trampoline"); + if ( trampoline_phys ) + return; + + if ( !cfg.addr ) + blexit(L"No memory for trampoline"); + + if ( efi_enabled(EFI_LOADER) ) relocate_trampoline(cfg.addr); - } } static void __init noreturn efi_arch_post_exit_boot(void) @@ -653,6 +658,43 @@ static bool_t __init efi_arch_use_config_file(EFI_SYSTEM_TABLE *SystemTable) static void efi_arch_flush_dcache_area(const void *vaddr, UINTN size) { } +paddr_t __init efi_multiboot2(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable) +{ + EFI_GRAPHICS_OUTPUT_PROTOCOL *gop; + UINTN cols, gop_mode = ~0, rows; + + __set_bit(EFI_BOOT, &efi_flags); + __set_bit(EFI_RS, &efi_flags); + + efi_init(ImageHandle, SystemTable); + + efi_console_set_mode(); + + if ( StdOut->QueryMode(StdOut, StdOut->Mode->Mode, + &cols, &rows) == EFI_SUCCESS ) + efi_arch_console_init(cols, rows); + + gop = efi_get_gop(); + + if ( gop ) + gop_mode = efi_find_gop_mode(gop, 0, 0, 0); + + efi_arch_edd(); + efi_arch_cpu(); + + efi_tables(); + setup_efi_pci(); + efi_variables(); + + if ( gop ) + efi_set_gop_mode(gop, gop_mode); + + efi_exit_boot(ImageHandle, SystemTable); + + /* Return highest usable memory address below 1 MiB. */ + return cfg.addr; +} + /* * Local variables: * mode: C diff --git a/xen/arch/x86/efi/stub.c b/xen/arch/x86/efi/stub.c index 4158124..6ea6aa1 100644 --- a/xen/arch/x86/efi/stub.c +++ b/xen/arch/x86/efi/stub.c @@ -3,6 +3,44 @@ #include <xen/init.h> #include <xen/lib.h> #include <asm/page.h> +#include <asm/efibind.h> +#include <efi/efidef.h> +#include <efi/eficapsule.h> +#include <efi/eficon.h> +#include <efi/efidevp.h> +#include <efi/efiapi.h> + +/* + * Here we are in EFI stub. EFI calls are not supported due to lack + * of relevant functionality in compiler and/or linker. + * + * efi_multiboot2() is an exception. Please look below for more details. + */ + +paddr_t __init noreturn efi_multiboot2(EFI_HANDLE ImageHandle, + EFI_SYSTEM_TABLE *SystemTable) +{ + CHAR16 *err = L"Xen does not have EFI code build in!!!\r\nSystem halted!!!\r\n"; + SIMPLE_TEXT_OUTPUT_INTERFACE *StdErr; + + StdErr = SystemTable->StdErr ? SystemTable->StdErr : SystemTable->ConOut; + + /* + * Print error message and halt the system. + * + * We have to open code MS x64 calling convention + * in assembly because here this convention may + * not be directly supported by C compiler. + */ + asm volatile( + " call %2 \n" + "0: hlt \n" + " jmp 0b \n" + : "+c" (StdErr), "+d" (err) : "g" (StdErr->OutputString) + : "rax", "r8", "r9", "r10", "r11", "memory"); + + unreachable(); +} bool efi_enabled(unsigned int feature) { diff --git a/xen/arch/x86/x86_64/asm-offsets.c b/xen/arch/x86/x86_64/asm-offsets.c index b437a8f..2a22659 100644 --- a/xen/arch/x86/x86_64/asm-offsets.c +++ b/xen/arch/x86/x86_64/asm-offsets.c @@ -175,6 +175,8 @@ void __dummy__(void) OFFSET(MB2_tag_type, multiboot2_tag_t, type); OFFSET(MB2_tag_size, multiboot2_tag_t, size); OFFSET(MB2_mem_lower, multiboot2_tag_basic_meminfo_t, mem_lower); + OFFSET(MB2_efi64_st, multiboot2_tag_efi64_t, pointer); + OFFSET(MB2_efi64_ih, multiboot2_tag_efi64_ih_t, pointer); BLANK(); OFFSET(DOMAIN_vm_assist, struct domain, vm_assist); diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S index b0b1c9b..e0e2529 100644 --- a/xen/arch/x86/xen.lds.S +++ b/xen/arch/x86/xen.lds.S @@ -331,5 +331,5 @@ ASSERT(IS_ALIGNED(__init_end, PAGE_SIZE), "__init_end misaligned") ASSERT(IS_ALIGNED(trampoline_start, 4), "trampoline_start misaligned") ASSERT(IS_ALIGNED(trampoline_end, 4), "trampoline_end misaligned") -ASSERT(IS_ALIGNED(__bss_start, 4), "__bss_start misaligned") -ASSERT(IS_ALIGNED(__bss_end, 4), "__bss_end misaligned") +ASSERT(IS_ALIGNED(__bss_start, 8), "__bss_start misaligned") +ASSERT(IS_ALIGNED(__bss_end, 8), "__bss_end misaligned") diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c index 46559f0..6e2cc23 100644 --- a/xen/common/efi/boot.c +++ b/xen/common/efi/boot.c @@ -79,6 +79,17 @@ static size_t wstrlen(const CHAR16 * s); static int set_color(u32 mask, int bpp, u8 *pos, u8 *sz); static bool_t match_guid(const EFI_GUID *guid1, const EFI_GUID *guid2); +static void efi_init(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable); +static void efi_console_set_mode(void); +static EFI_GRAPHICS_OUTPUT_PROTOCOL *efi_get_gop(void); +static UINTN efi_find_gop_mode(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop, + UINTN cols, UINTN rows, UINTN depth); +static void efi_tables(void); +static void setup_efi_pci(void); +static void efi_variables(void); +static void efi_set_gop_mode(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop, UINTN gop_mode); +static void efi_exit_boot(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable); + static const EFI_BOOT_SERVICES *__initdata efi_bs; static UINT32 __initdata efi_bs_revision; static EFI_HANDLE __initdata efi_ih; -- 1.7.10.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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