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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 20/23] x86: add multiboot2 protocol support for EFI platforms
On Mon, Jul 20, 2015 at 04:29:15PM +0200, Daniel Kiper wrote:
> Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
> ---
> 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 | 157
> +++++++++++++++++++++++++++++++++++--
> xen/arch/x86/efi/efi-boot.h | 30 +++++++
> xen/arch/x86/efi/stub.c | 5 ++
> xen/arch/x86/setup.c | 10 ++-
> xen/arch/x86/x86_64/asm-offsets.c | 2 +
> xen/arch/x86/xen.lds.S | 4 +-
> xen/common/efi/boot.c | 12 +++
> xen/include/xen/efi.h | 1 +
> 8 files changed, 210 insertions(+), 11 deletions(-)
>
> diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S
> index 57197db..056047f 100644
> --- a/xen/arch/x86/boot/head.S
> +++ b/xen/arch/x86/boot/head.S
> @@ -89,6 +89,13 @@ multiboot1_header_end:
> 0, /* Number of the lines - no preference. */ \
> 0 /* Number of bits per pixel - no preference. */
>
> + /* Do not disable EFI boot services. */
s/disable/exit/ ?
Or perhaps:
/* Inhibit GRUB2 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:
> @@ -100,9 +107,15 @@ multiboot1_header_end:
> 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
>
> .Lbad_cpu_msg: .asciz "ERR: Not a 64-bit CPU!"
> .Lbad_ldr_msg: .asciz "ERR: Not a Multiboot bootloader!"
> +.Lbad_mb2_ldr: .asciz "ERR: Use latest Multiboot2 compatible bootloader!"
Multiboot2+EFI compatible..?
>
> .section .init.text, "ax", @progbits
>
> @@ -111,6 +124,9 @@ bad_cpu:
> jmp print_err
> not_multiboot:
> mov $(sym_phys(.Lbad_ldr_msg)),%esi # Error message
> + jmp print_err
> +mb2_too_old:
> + mov $(sym_phys(.Lbad_mb2_ldr)),%esi # Error message
> print_err:
> mov $0xB8000,%edi # VGA framebuffer
> 1: mov (%esi),%bl
> @@ -130,6 +146,119 @@ print_err:
> .Lhalt: hlt
> jmp .Lhalt
>
> + .code64
> +
> +__efi64_start:
> + cld
> +
> + /* Check for Multiboot2 bootloader. */
> + cmp $MULTIBOOT2_BOOTLOADER_MAGIC,%eax
> + je efi_multiboot2_proto
> +
> + /* Jump to not_multiboot after switching CPU to x86_32 mode. */
> + lea not_multiboot(%rip),%rdi
> + jmp x86_32_switch
> +
> +efi_multiboot2_proto:
> + /*
> + * Multiboot2 information address is 32-bit,
> + * so, zero higher half of %rbx.
> + */
> + mov %ebx,%ebx
> +
> + /* Skip Multiboot2 information fixed part. */
> + lea MB2_fixed_sizeof(%rbx),%rcx
Don't want to check that the address is aligned properly?
> +
> +0:
> + /* Get EFI SystemTable address from Multiboot2 information. */
> + cmpl $MULTIBOOT2_TAG_TYPE_EFI64,MB2_tag_type(%rcx)
> + jne 1f
> +
> + mov MB2_efi64_st(%rcx),%rsi
> +
> + /* Do not go into real mode on EFI platform. */
Add please:
/* And also inhibit clearing of BSS later on. */
> + movb $1,skip_realmode(%rip)
> + jmp 3f
> +
> +1:
> + /* Get EFI ImageHandle address from Multiboot2 information. */
> + cmpl $MULTIBOOT2_TAG_TYPE_EFI64_IH,MB2_tag_type(%rcx)
> + jne 2f
> +
> + mov MB2_efi64_ih(%rcx),%rdi
> + jmp 3f
> +
> +2:
> + /* Is it the end of Multiboot2 information? */
> + cmpl $MULTIBOOT2_TAG_TYPE_END,MB2_tag_type(%rcx)
> + je run_bs
> +
> +3:
> + /* Go to next Multiboot2 information tag. */
> + add MB2_tag_size(%rcx),%ecx
> + add $(MULTIBOOT2_TAG_ALIGN-1),%rcx
> + and $~(MULTIBOOT2_TAG_ALIGN-1),%rcx
> + jmp 0b
> +
> +run_bs:
> + push %rax
> + push %rdi
> +
> + /* Initialize BSS (no nasty surprises!). */
> + lea __bss_start(%rip),%rdi
> + lea __bss_end(%rip),%rcx
> + sub %rdi,%rcx
> + shr $3,%rcx
> + xor %eax,%eax
> + rep stosq
> +
> + pop %rdi
> +
> + /*
> + * IN: %rdi - EFI ImageHandle, %rsi - EFI SystemTable.
> + * OUT: %rax - multiboot2.mem_lower. Do not get this value from
> + * MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO tag. It could be bogus on
> + * EFI platforms.
> + */
> + call efi_multiboot2
> +
> + /* Convert multiboot2.mem_lower to bytes/16. */
> + mov %rax,%rcx
> + shr $4,%rcx
> +
> + pop %rax
> +
> + /* Jump to trampoline_setup after switching CPU to x86_32 mode. */
> + lea trampoline_setup(%rip),%rdi
> +
> +x86_32_switch:
> + cli
> +
> + /* Initialise GDT. */
> + lgdt gdt_boot_descr(%rip)
> +
> + /* Reload code selector. */
> + ljmpl *cs32_switch_addr(%rip)
> +
> + .code32
> +
> +cs32_switch:
> + /* Initialise basic data segments. */
> + mov $BOOT_DS,%edx
> + mov %edx,%ds
> + mov %edx,%es
> + mov %edx,%fs
> + mov %edx,%gs
> + mov %edx,%ss
> +
> + /* 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 +286,7 @@ __start:
>
> /* Not available? BDA value will be fine. */
> cmovnz MB_mem_lower(%ebx),%edx
> - jmp trampoline_setup
> + jmp trampoline_bios_setup
>
> multiboot2_proto:
> /* Skip Multiboot2 information fixed part. */
> @@ -169,12 +298,19 @@ multiboot2_proto:
> jne 1f
>
> mov MB2_mem_lower(%ecx),%edx
> - jmp trampoline_setup
> + jmp trampoline_bios_setup
>
> 1:
> + /* EFI mode is not supported via legacy BIOS path. */
> + cmpl $MULTIBOOT2_TAG_TYPE_EFI32,MB2_tag_type(%ecx)
> + je mb2_too_old
> +
> + cmpl $MULTIBOOT2_TAG_TYPE_EFI64,MB2_tag_type(%ecx)
> + je mb2_too_old
> +
> /* Is it the end of Multiboot2 information? */
> cmpl $MULTIBOOT2_TAG_TYPE_END,MB2_tag_type(%ecx)
> - je trampoline_setup
> + je trampoline_bios_setup
>
> /* Go to next Multiboot2 information tag. */
> add MB2_tag_size(%ecx),%ecx
> @@ -182,7 +318,7 @@ multiboot2_proto:
> and $~(MULTIBOOT2_TAG_ALIGN-1),%ecx
> jmp 0b
>
> -trampoline_setup:
> +trampoline_bios_setup:
> /* Set up trampoline segment 64k below EBDA */
> movzwl 0x40e,%ecx /* EBDA segment */
> cmp $0xa000,%ecx /* sanity check (high) */
> @@ -198,12 +334,13 @@ 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 */
> +trampoline_setup:
> + /* Reserve 64kb for the trampoline. */
> sub $0x1000,%ecx
>
> /* From arch/x86/smpboot.c: start_eip had better be page-aligned! */
> @@ -220,6 +357,13 @@ trampoline_setup:
> add $12,%esp /* Remove reloc() args from stack. */
> mov %eax,sym_phys(multiboot_ptr)
>
> + /*
> + * Do not zero BSS on EFI platform here.
> + * It was initialized earlier.
> + */
> + cmpb $1,sym_phys(skip_realmode)
> + je 1f
> +
> /* Initialize BSS (no nasty surprises!). */
> mov $sym_phys(__bss_start),%edi
> mov $sym_phys(__bss_end),%ecx
> @@ -228,6 +372,7 @@ trampoline_setup:
> xor %eax,%eax
> rep stosl
>
> +1:
> /* Interrogate CPU extended features via CPUID. */
> mov $0x80000000,%eax
> cpuid
> diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
> index 3d25c48..1b25a2d 100644
> --- a/xen/arch/x86/efi/efi-boot.h
> +++ b/xen/arch/x86/efi/efi-boot.h
> @@ -228,6 +228,9 @@ static void *__init efi_arch_allocate_mmap_buffer(UINTN
> map_size)
>
> static void __init efi_arch_pre_exit_boot(void)
> {
> + if ( !efi_enabled(EFI_LOADER) )
> + return;
> +
> if ( !trampoline_phys )
> {
> if ( !cfg.addr )
> @@ -662,6 +665,33 @@ static bool_t __init
> efi_arch_use_config_file(EFI_SYSTEM_TABLE *SystemTable)
> return 1; /* x86 always uses a config file */
> }
>
> +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_PLATFORM, &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();
> + gop_mode = efi_find_gop_mode(gop, 0, 0, 0);
> + efi_arch_edd();
> + efi_tables();
> + setup_efi_pci();
> + efi_variables();
> + efi_set_gop_mode(gop, gop_mode);
> + efi_exit_boot(ImageHandle, SystemTable);
> +
> + return cfg.addr;
> +}
> +
> /*
> * Local variables:
> * mode: C
> diff --git a/xen/arch/x86/efi/stub.c b/xen/arch/x86/efi/stub.c
> index c5ae369..d30fe89 100644
> --- a/xen/arch/x86/efi/stub.c
> +++ b/xen/arch/x86/efi/stub.c
> @@ -13,6 +13,11 @@ struct efi __read_mostly efi = {
> .smbios3 = EFI_INVALID_TABLE_ADDR
> };
>
> +void __init efi_multiboot2(void)
> +{
> + /* TODO: Fail if entered! */
Heheh. Could we add the 'ud2' instruction here?
> +}
> +
> void __init efi_init_memory(void) { }
>
> void efi_update_l4_pgtable(unsigned int l4idx, l4_pgentry_t l4e) { }
> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
> index a59fc4e..8bec67f 100644
> --- a/xen/arch/x86/setup.c
> +++ b/xen/arch/x86/setup.c
> @@ -695,7 +695,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
> if ( !(mbi->flags & MBI_MODULES) || (mbi->mods_count == 0) )
> panic("dom0 kernel not specified. Check bootloader configuration.");
>
> - if ( efi_enabled(EFI_PLATFORM) )
> + if ( efi_enabled(EFI_LOADER) )
> {
> set_pdx_range(xen_phys_start >> PAGE_SHIFT,
> (xen_phys_start + BOOTSTRAP_MAP_BASE) >> PAGE_SHIFT);
> @@ -708,7 +708,11 @@ void __init noreturn __start_xen(unsigned long mbi_p)
> l3_bootmap[l3_table_offset(BOOTSTRAP_MAP_BASE)] =
> l3e_from_paddr(__pa(l2_bootmap), __PAGE_HYPERVISOR);
>
> - memmap_type = loader;
> + memmap_type = "EFI";
> + }
> + else if ( efi_enabled(EFI_PLATFORM) )
> + {
> + memmap_type = "EFI";
> }
> else if ( e820_raw_nr != 0 )
> {
> @@ -806,7 +810,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
> * we can relocate the dom0 kernel and other multiboot modules. Also, on
> * x86/64, we relocate Xen to higher memory.
> */
> - for ( i = 0; !efi_enabled(EFI_PLATFORM) && i < mbi->mods_count; i++ )
> + for ( i = 0; !efi_enabled(EFI_LOADER) && i < mbi->mods_count; i++ )
> {
> if ( mod[i].mod_start & (PAGE_SIZE - 1) )
> panic("Bootloader didn't honor module alignment request.");
> diff --git a/xen/arch/x86/x86_64/asm-offsets.c
> b/xen/arch/x86/x86_64/asm-offsets.c
> index b926082..b7aed49 100644
> --- a/xen/arch/x86/x86_64/asm-offsets.c
> +++ b/xen/arch/x86/x86_64/asm-offsets.c
> @@ -173,4 +173,6 @@ 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);
> }
> diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S
> index 87f3e83..a399615 100644
> --- a/xen/arch/x86/xen.lds.S
> +++ b/xen/arch/x86/xen.lds.S
> @@ -162,7 +162,7 @@ SECTIONS
> . = ALIGN(STACK_SIZE);
> __init_end = .;
>
> - . = ALIGN(4);
> + . = ALIGN(8);
> .bss : { /* BSS */
> __bss_start = .;
> *(.bss.stack_aligned)
> @@ -176,7 +176,7 @@ SECTIONS
> *(.bss.percpu.read_mostly)
> . = ALIGN(SMP_CACHE_BYTES);
> __per_cpu_data_end = .;
> - . = ALIGN(4);
> + . = ALIGN(8);
This aligment check I presume is due to 'rep stosq'?
As such could you add a comment here please?
> __bss_end = .;
> } :text
> _end = . ;
> diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
> index bf2f198..5a02e71 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;
> @@ -960,6 +971,7 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE
> *SystemTable)
>
> #ifndef CONFIG_ARM /* Disabled until runtime services implemented. */
> set_bit(EFI_PLATFORM, &efi.flags);
> + set_bit(EFI_LOADER, &efi.flags);
> #endif
>
> efi_init(ImageHandle, SystemTable);
> diff --git a/xen/include/xen/efi.h b/xen/include/xen/efi.h
> index 318bbec..6b952df 100644
> --- a/xen/include/xen/efi.h
> +++ b/xen/include/xen/efi.h
> @@ -9,6 +9,7 @@
> #define EFI_INVALID_TABLE_ADDR (~0UL)
>
> #define EFI_PLATFORM 0
> +#define EFI_LOADER 1
>
> /* Add fields here only if they need to be referenced from non-EFI code. */
> struct efi {
With the changes above:
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> --
> 1.7.10.4
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel
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