From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH for-xen-4.5 v4 18/18] xen/x86: add multiboot2 protocol support Date: Sat, 18 Oct 2014 00:13:35 +0100 Message-ID: <5441A29F.3060008@citrix.com> References: <1413555132-22138-1-git-send-email-daniel.kiper@oracle.com> <1413555132-22138-19-git-send-email-daniel.kiper@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1XfGiJ-0000ue-LD for xen-devel@lists.xenproject.org; Fri, 17 Oct 2014 23:13:39 +0000 In-Reply-To: <1413555132-22138-19-git-send-email-daniel.kiper@oracle.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Daniel Kiper , xen-devel@lists.xenproject.org Cc: jgross@suse.com, keir@xen.org, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, ross.philipson@citrix.com, roy.franz@linaro.org, ning.sun@intel.com, jbeulich@suse.com, qiaowei.ren@intel.com, richard.l.maliszewski@intel.com, gang.wei@intel.com, fu.wei@linaro.org List-Id: xen-devel@lists.xenproject.org On 17/10/2014 15:12, Daniel Kiper wrote: > Add multiboot2 protocol support. Alter min memory limit handling as we > now may not find it from either multiboot (v1) or multiboot2. > > This way we are laying the foundation for EFI + GRUB2 + Xen development. > > Signed-off-by: Daniel Kiper > --- > v4 - suggestions/fixes: > - use macro to get multiboot2 data > (suggested by Jan Beulich), > - use named constant in assembly files > (suggested by Andrew Cooper), > - rearrange condition for multiboot protocol version > detection; fallback to multiboot(1) if protocol > is unknown > (suggested by Andrew Cooper), > - improve multiboot2 header comment in head.S > (suggested by Jan Beulich). > > v3 - suggestions/fixes: > - rearrange assembly a bit > (suggested by Andrew Cooper), > - define only used structs in multiboot2.h > (suggested by Andrew Cooper), > - improve commit comment > (suggested by Andrew Cooper), > - further patch split rearrangement > (suggested by Andrew Cooper). > > v2 - suggestions/fixes: > - use "for" instead of "while" for loops > (suggested by Jan Beulich), > - properly parenthesize macro arguments > (suggested by Jan Beulich), > - change some local variables types > (suggested by Jan Beulich), > - use meaningful labels > (suggested by Andrew Cooper and Jan Beulich), > - use local labels > (suggested by Jan Beulich), > - fix coding style > (suggested by Jan Beulich), > - patch split rearrangement > (suggested by Andrew Cooper and Jan Beulich). > --- > xen/arch/x86/boot/Makefile | 3 +- > xen/arch/x86/boot/head.S | 132 ++++++++++++++++++++++++++++++-- > xen/arch/x86/boot/reloc.c | 119 ++++++++++++++++++++++++++++- > xen/arch/x86/x86_64/asm-offsets.c | 6 ++ > xen/include/xen/multiboot2.h | 153 +++++++++++++++++++++++++++++++++++++ > 5 files changed, 401 insertions(+), 12 deletions(-) > create mode 100644 xen/include/xen/multiboot2.h > > diff --git a/xen/arch/x86/boot/Makefile b/xen/arch/x86/boot/Makefile > index e6ff2b7..031a758 100644 > --- a/xen/arch/x86/boot/Makefile > +++ b/xen/arch/x86/boot/Makefile > @@ -1,7 +1,8 @@ > obj-bin-y += head.o > > RELOC_DEPS = $(BASEDIR)/include/asm-x86/config.h $(BASEDIR)/include/xen/compiler.h \ > - $(BASEDIR)/include/xen/multiboot.h $(BASEDIR)/include/asm-x86/mbd.h > + $(BASEDIR)/include/xen/multiboot.h $(BASEDIR)/include/xen/multiboot2.h \ > + $(BASEDIR)/include/asm-x86/mbd.h > > export RELOC_DEPS > > diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S > index 12e41f9..e9a5955 100644 > --- a/xen/arch/x86/boot/head.S > +++ b/xen/arch/x86/boot/head.S > @@ -1,5 +1,6 @@ > #include > #include > +#include > #include > #include > #include > @@ -33,6 +34,82 @@ ENTRY(start) > /* Checksum: must be the negated sum of the first two fields. */ > .long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS) > > +/*** MULTIBOOT2 HEADER ****/ > +/* Some ideas are taken from grub-2.00/grub-core/tests/boot/kernel-i386.S file. */ > + .align MULTIBOOT2_HEADER_ALIGN > + > +.Lmultiboot2_header: > + /* Magic number indicating a Multiboot2 header. */ > + .long MULTIBOOT2_HEADER_MAGIC > + /* Architecture: i386. */ > + .long MULTIBOOT2_ARCHITECTURE_I386 > + /* Multiboot2 header length. */ > + .long .Lmultiboot2_header_end - .Lmultiboot2_header > + /* Multiboot2 header checksum. */ > + .long -(MULTIBOOT2_HEADER_MAGIC + MULTIBOOT2_ARCHITECTURE_I386 + \ > + (.Lmultiboot2_header_end - .Lmultiboot2_header)) > + > + /* Multiboot2 tags... */ > +.Lmultiboot2_info_req: > + /* Multiboot2 information request tag. */ > + .short MULTIBOOT2_HEADER_TAG_INFORMATION_REQUEST > + .short MULTIBOOT2_HEADER_TAG_REQUIRED > + .long .Lmultiboot2_info_req_end - .Lmultiboot2_info_req > + .long MULTIBOOT2_TAG_TYPE_MMAP > +.Lmultiboot2_info_req_end: > + > + /* > + * Align Xen image and modules at page boundry. > + * > + * .balignl MULTIBOOT2_TAG_ALIGN, MULTIBOOT2_TAG_TYPE_END is a hack > + * to avoid bug related to Multiboot2 information request tag in earlier > + * versions of GRUB2. > + * > + * DO NOT MOVE THIS TAG! ANY CHANGE HERE MAY BREAK COMPATIBILITY > + * WITH EARLIER GRUB2 VERSIONS! > + * > + * Earlier versions of GRUB2 incorrectly calculate Multiboot2 information > + * request tag size and read past the end of it 8 bytes. It means that > + * these 8 bytes must contain something valid in terms of request tag. > + * Fortunately next tag has MULTIBOOT2_TAG_TYPE_MMAP meaning as a request > + * and as is it does not change anything in our request because we asked > + * for that thing above. However, if request tag ends at unaligned address > + * and .align is used then compiler may put random value in void before > + * first tag. This could not be accepted by earlier versions of GRUB2 and > + * Xen load would fail. So, use .balignl and forcibly fill this void with > + * something valid in terms of request tag. However, this thing should not > + * change our request in significant way. MULTIBOOT2_TAG_TYPE_END satisfies > + * these assumptions because GRUB2 must provide ending tag for list of > + * arguments even if it was not explicitly requested. > + */ > + .balignl MULTIBOOT2_TAG_ALIGN, MULTIBOOT2_TAG_TYPE_END > + .short MULTIBOOT2_HEADER_TAG_MODULE_ALIGN > + .short MULTIBOOT2_HEADER_TAG_REQUIRED > + .long 8 /* Tag size. */ > + > + /* Console flags tag. */ > + .align MULTIBOOT2_TAG_ALIGN > + .short MULTIBOOT2_HEADER_TAG_CONSOLE_FLAGS > + .short MULTIBOOT2_HEADER_TAG_OPTIONAL > + .long 12 /* Tag size. */ > + .long MULTIBOOT2_CONSOLE_FLAGS_EGA_TEXT_SUPPORTED > + > + /* Framebuffer tag. */ > + .align MULTIBOOT2_TAG_ALIGN > + .short MULTIBOOT2_HEADER_TAG_FRAMEBUFFER > + .short MULTIBOOT2_HEADER_TAG_OPTIONAL > + .long 20 /* Tag size. */ > + .long 0 /* Number of the columns - no preference. */ > + .long 0 /* Number of the lines - no preference. */ > + .long 0 /* Number of bits per pixel - no preference. */ > + > + /* Multiboot2 header end tag. */ > + .align MULTIBOOT2_TAG_ALIGN > + .short MULTIBOOT2_HEADER_TAG_END > + .short 0 > + .long 8 /* Tag size. */ > +.Lmultiboot2_header_end: > + > .section .init.rodata, "a", @progbits > .align 4 > > @@ -81,10 +158,54 @@ __start: > mov %ecx,%es > mov %ecx,%ss > > + /* Assume multiboot[12].mem_lower is 0 if not set by bootloader */ > + xor %edx,%edx > + > /* Check for Multiboot bootloader */ > cmp $MULTIBOOT_BOOTLOADER_MAGIC,%eax > - jne not_multiboot > + je multiboot_proto > + > + /* Check for Multiboot2 bootloader */ > + cmp $MULTIBOOT2_BOOTLOADER_MAGIC,%eax > + je multiboot2_proto > + > + jmp not_multiboot > + > +multiboot_proto: > + /* Get mem_lower from Multiboot information */ > + testb $MBI_MEMLIMITS,(%ebx) > + jz trampoline_setup /* not available? BDA value will be fine */ > + > + mov MBI_mem_lower(%ebx),%edx > + jmp trampoline_setup > + > +multiboot2_proto: > + /* Get Multiboot2 information address */ > + mov %ebx,%ecx > + > + /* Skip Multiboot2 information fixed part */ > + add $MBI2_fixed_sizeof,%ecx > + > +0: > + /* Get mem_lower from Multiboot2 information */ > + cmpl $MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO,(%ecx) > + jne 1f > + > + mov MBI2_mem_lower(%ecx),%edx > + jmp trampoline_setup > > +1: > + /* Is it the end of Multiboot2 information? */ > + cmpl $MULTIBOOT2_TAG_TYPE_END,(%ecx) > + je trampoline_setup > + > + /* Go to next Multiboot2 information tag */ > + add MBI2_tag_size(%ecx),%ecx > + add $(MULTIBOOT2_TAG_ALIGN-1),%ecx > + and $~(MULTIBOOT2_TAG_ALIGN-1),%ecx > + jmp 0b > + > +trampoline_setup: > /* Set up trampoline segment 64k below EBDA */ > movzwl 0x40e,%ecx /* EBDA segment */ > cmp $0xa000,%ecx /* sanity check (high) */ > @@ -99,9 +220,6 @@ __start: > * Compare the value in the BDA with the information from the > * multiboot structure (if available) and use the smallest. > */ > - testb $MBI_MEMLIMITS,(%ebx) > - jz 2f /* not available? BDA value will be fine */ > - mov MBI_mem_lower(%ebx),%edx > cmp $0x100,%edx /* is the multiboot value too small? */ > jb 2f /* if so, do not use it */ > shl $10-4,%edx > @@ -116,11 +234,11 @@ __start: > shl $4, %ecx > mov %ecx,sym_phys(trampoline_phys) > > - /* Save the Multiboot info struct (after relocation) for later use. */ > + /* Save the Multiboot data (after relocation) for later use. */ > mov $sym_phys(cpu0_stack)+1024,%esp > - mov %ecx,%eax > + push %eax /* Multiboot magic */ > push %ebx /* Multiboot information address */ > - call reloc /* %eax contains trampoline address */ > + call reloc /* %ecx contains trampoline address */ > mov %eax,sym_phys(mbd_pa) > > /* Initialize BSS (no nasty surprises!) */ > diff --git a/xen/arch/x86/boot/reloc.c b/xen/arch/x86/boot/reloc.c > index 9792fcd..4984b00 100644 > --- a/xen/arch/x86/boot/reloc.c > +++ b/xen/arch/x86/boot/reloc.c > @@ -5,19 +5,26 @@ > * and modules. This is most easily done early with paging disabled. > * > * Copyright (c) 2009, Citrix Systems, Inc. > + * Copyright (c) 2013, 2014 Oracle Corp. > * > * Authors: > * Keir Fraser > + * Daniel Kiper > */ > > -/* entered with %eax = BOOT_TRAMPOLINE */ > +/* > + * This entry point is entered from xen/arch/x86/boot/head.S with: > + * - %eax = MULTIBOOT_MAGIC, > + * - %ebx = MULTIBOOT_INFORMATION_ADDRESS, > + * - %ecx = BOOT_TRAMPOLINE. > + */ > asm ( > " .text \n" > " .globl _start \n" > "_start: \n" > " call 1f \n" > "1: pop %ebx \n" > - " mov %eax,alloc-1b(%ebx) \n" > + " mov %ecx,alloc-1b(%ebx) \n" > " jmp reloc \n" > ); > > @@ -31,12 +38,19 @@ asm ( > ); > > typedef unsigned int u32; > +typedef unsigned long long u64; > > #include "../../../include/xen/compiler.h" > #include "../../../include/xen/multiboot.h" > +#include "../../../include/xen/multiboot2.h" > > #include "../../../include/asm/mbd.h" > > +#define ALIGN_UP(addr, align) \ > + (((addr) + (typeof(addr))(align) - 1) & ~((typeof(addr))(align) - 1)) > + > +#define get_mb2_data(tag, type, member) (((type *)(tag))->member) All the mb2 tag types have a common .type and .size field at the head. You should make a struct with a union in it (similar to a domctl/sysctl) and avoid all this type punning. > + > static u32 alloc_struct(u32 bytes) > { > u32 s; > @@ -127,12 +141,109 @@ static mbd_t *mb_mbd(mbd_t *mbd, multiboot_info_t *mbi) > return mbd; > } > > -static mbd_t __used *reloc(void *mbi) > +static mbd_t *mb2_mbd(mbd_t *mbd, void *mbi) > +{ > + boot_module_t *mbd_mods; > + memory_map_t *mmap_dst; > + multiboot2_memory_map_t *mmap_src; > + multiboot2_tag_t *tag; > + u32 ptr; > + unsigned int i, mod_idx = 0; > + > + /* Skip Multiboot2 information fixed part. */ > + tag = mbi + sizeof(multiboot2_fixed_t); > + > + for ( ; ; ) > + { > + if ( tag->type == MULTIBOOT2_TAG_TYPE_MODULE ) > + ++mbd->mods_nr; > + else if ( tag->type == MULTIBOOT2_TAG_TYPE_END ) > + { > + mbd->mods = alloc_struct(mbd->mods_nr * sizeof(boot_module_t)); > + mbd_mods = (boot_module_t *)mbd->mods; > + break; > + } > + > + /* Go to next Multiboot2 information tag. */ > + tag = (multiboot2_tag_t *)(ALIGN_UP((u32)tag + tag->size, MULTIBOOT2_TAG_ALIGN)); > + } > + > + /* Skip Multiboot2 information fixed part. */ > + tag = mbi + sizeof(multiboot2_fixed_t); > + > + for ( ; ; ) > + { > + switch ( tag->type ) > + { > + case MULTIBOOT2_TAG_TYPE_BOOT_LOADER_NAME: > + ptr = (u32)get_mb2_data(tag, multiboot2_tag_string_t, string); > + mbd->boot_loader_name = copy_string(ptr); > + break; > + > + case MULTIBOOT2_TAG_TYPE_CMDLINE: > + ptr = (u32)get_mb2_data(tag, multiboot2_tag_string_t, string); > + mbd->cmdline = copy_string(ptr); > + break; > + > + case MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO: > + mbd->mem_lower = get_mb2_data(tag, multiboot2_tag_basic_meminfo_t, mem_lower); > + mbd->mem_upper = get_mb2_data(tag, multiboot2_tag_basic_meminfo_t, mem_upper); > + break; > + > + case MULTIBOOT2_TAG_TYPE_MMAP: > + mbd->mmap_size = get_mb2_data(tag, multiboot2_tag_mmap_t, size); > + mbd->mmap_size -= sizeof(multiboot2_tag_mmap_t); > + mbd->mmap_size += sizeof(((multiboot2_tag_mmap_t){0}).entries); > + mbd->mmap_size /= get_mb2_data(tag, multiboot2_tag_mmap_t, entry_size); > + mbd->mmap_size *= sizeof(memory_map_t); Yikes. (want to see about getting a %= in there for the full set of operators?) Is this > + > + mbd->mmap = alloc_struct(mbd->mmap_size); > + > + mmap_src = get_mb2_data(tag, multiboot2_tag_mmap_t, entries); > + mmap_dst = (memory_map_t *)mbd->mmap; > + > + for ( i = 0; i < mbd->mmap_size / sizeof(memory_map_t); ++i ) > + { > + mmap_dst[i].size = sizeof(memory_map_t); > + mmap_dst[i].size -= sizeof(((memory_map_t){0}).size); > + mmap_dst[i].base_addr_low = (u32)mmap_src[i].addr; > + mmap_dst[i].base_addr_high = (u32)(mmap_src[i].addr >> 32); > + mmap_dst[i].length_low = (u32)mmap_src[i].len; > + mmap_dst[i].length_high = (u32)(mmap_src[i].len >> 32); > + mmap_dst[i].type = mmap_src[i].type; > + } > + break; > + > + case MULTIBOOT2_TAG_TYPE_MODULE: > + mbd_mods[mod_idx].start = get_mb2_data(tag, multiboot2_tag_module_t, mod_start); > + mbd_mods[mod_idx].end = get_mb2_data(tag, multiboot2_tag_module_t, mod_end); > + ptr = (u32)get_mb2_data(tag, multiboot2_tag_module_t, cmdline); > + mbd_mods[mod_idx].cmdline = copy_string(ptr); > + mbd_mods[mod_idx].relocated = 0; > + ++mod_idx; > + break; > + > + case MULTIBOOT2_TAG_TYPE_END: > + return mbd; > + > + default: > + break; > + } > + > + /* Go to next Multiboot2 information tag. */ > + tag = (multiboot2_tag_t *)(ALIGN_UP((u32)tag + tag->size, MULTIBOOT2_TAG_ALIGN)); > + } > +} > + > +static mbd_t __used *reloc(void *mbi, u32 mb_magic) > { > mbd_t *mbd; > > mbd = (mbd_t *)alloc_struct(sizeof(*mbd)); > zero_struct((u32)mbd, sizeof(*mbd)); > > - return mb_mbd(mbd, mbi); > + if ( mb_magic == MULTIBOOT2_BOOTLOADER_MAGIC ) > + return mb2_mbd(mbd, mbi); > + else > + return mb_mbd(mbd, mbi); > } > diff --git a/xen/arch/x86/x86_64/asm-offsets.c b/xen/arch/x86/x86_64/asm-offsets.c > index 7364dd6..ac4ce93 100644 > --- a/xen/arch/x86/x86_64/asm-offsets.c > +++ b/xen/arch/x86/x86_64/asm-offsets.c > @@ -10,6 +10,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -167,5 +168,10 @@ void __dummy__(void) > OFFSET(MBI_mem_lower, multiboot_info_t, mem_lower); > BLANK(); > > + DEFINE(MBI2_fixed_sizeof, sizeof(multiboot2_fixed_t)); > + OFFSET(MBI2_tag_size, multiboot2_tag_t, size); > + OFFSET(MBI2_mem_lower, multiboot2_tag_basic_meminfo_t, mem_lower); > + BLANK(); > + > OFFSET(MBD_cmdline, mbd_t, cmdline); > } > diff --git a/xen/include/xen/multiboot2.h b/xen/include/xen/multiboot2.h > new file mode 100644 > index 0000000..95eaa76 > --- /dev/null > +++ b/xen/include/xen/multiboot2.h > @@ -0,0 +1,153 @@ > +/* > + * Copyright (C) 1999,2003,2007,2008,2009,2010 Free Software Foundation, Inc. > + * > + * multiboot2.h - Multiboot 2 header file. > + * > + * Based on grub-2.00/include/multiboot2.h file. > + * > + * Permission is hereby granted, free of charge, to any person obtaining a copy > + * of this software and associated documentation files (the "Software"), to > + * deal in the Software without restriction, including without limitation the > + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or > + * sell copies of the Software, and to permit persons to whom the Software is > + * furnished to do so, subject to the following conditions: > + * > + * The above copyright notice and this permission notice shall be included in > + * all copies or substantial portions of the Software. > + * > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL ANY > + * DEVELOPER OR DISTRIBUTOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, > + * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR > + * IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. > + */ > + > +#ifndef __MULTIBOOT2_H__ > +#define __MULTIBOOT2_H__ > + > +/* The magic field should contain this. */ > +#define MULTIBOOT2_HEADER_MAGIC 0xe85250d6 > + > +/* This should be in %eax on x86 architecture. */ > +#define MULTIBOOT2_BOOTLOADER_MAGIC 0x36d76289 > + > +/* How many bytes from the start of the file we search for the header. */ > +#define MULTIBOOT2_SEARCH 32768 > + > +/* Multiboot 2 header alignment. */ > +#define MULTIBOOT2_HEADER_ALIGN 8 > + > +/* Alignment of multiboot 2 modules. */ > +#define MULTIBOOT2_MOD_ALIGN 0x00001000 > + > +/* Alignment of the multiboot 2 info structure. */ > +#define MULTIBOOT2_INFO_ALIGN 0x00000008 > + > +/* Multiboot 2 architectures. */ > +#define MULTIBOOT2_ARCHITECTURE_I386 0 > +#define MULTIBOOT2_ARCHITECTURE_MIPS32 4 > + > +/* Header tag types. */ > +#define MULTIBOOT2_HEADER_TAG_END 0 > +#define MULTIBOOT2_HEADER_TAG_INFORMATION_REQUEST 1 > +#define MULTIBOOT2_HEADER_TAG_ADDRESS 2 > +#define MULTIBOOT2_HEADER_TAG_ENTRY_ADDRESS 3 > +#define MULTIBOOT2_HEADER_TAG_CONSOLE_FLAGS 4 > +#define MULTIBOOT2_HEADER_TAG_FRAMEBUFFER 5 > +#define MULTIBOOT2_HEADER_TAG_MODULE_ALIGN 6 > +#define MULTIBOOT2_HEADER_TAG_EFI_BS 7 > + > +/* Header tag flags. */ > +#define MULTIBOOT2_HEADER_TAG_REQUIRED 0 > +#define MULTIBOOT2_HEADER_TAG_OPTIONAL 1 > + > +/* Header console tag console_flags. */ > +#define MULTIBOOT2_CONSOLE_FLAGS_CONSOLE_REQUIRED 1 > +#define MULTIBOOT2_CONSOLE_FLAGS_EGA_TEXT_SUPPORTED 2 > + > +/* Flags set in the 'flags' member of the multiboot header. */ > +#define MULTIBOOT2_TAG_TYPE_END 0 > +#define MULTIBOOT2_TAG_TYPE_CMDLINE 1 > +#define MULTIBOOT2_TAG_TYPE_BOOT_LOADER_NAME 2 > +#define MULTIBOOT2_TAG_TYPE_MODULE 3 > +#define MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO 4 > +#define MULTIBOOT2_TAG_TYPE_BOOTDEV 5 > +#define MULTIBOOT2_TAG_TYPE_MMAP 6 > +#define MULTIBOOT2_TAG_TYPE_VBE 7 > +#define MULTIBOOT2_TAG_TYPE_FRAMEBUFFER 8 > +#define MULTIBOOT2_TAG_TYPE_ELF_SECTIONS 9 > +#define MULTIBOOT2_TAG_TYPE_APM 10 > +#define MULTIBOOT2_TAG_TYPE_EFI32 11 > +#define MULTIBOOT2_TAG_TYPE_EFI64 12 > +#define MULTIBOOT2_TAG_TYPE_SMBIOS 13 > +#define MULTIBOOT2_TAG_TYPE_ACPI_OLD 14 > +#define MULTIBOOT2_TAG_TYPE_ACPI_NEW 15 > +#define MULTIBOOT2_TAG_TYPE_NETWORK 16 > +#define MULTIBOOT2_TAG_TYPE_EFI_MMAP 17 > +#define MULTIBOOT2_TAG_TYPE_EFI_BS 18 > + > +/* Multiboot 2 tag alignment. */ > +#define MULTIBOOT2_TAG_ALIGN 8 > + > +/* Memory types. */ > +#define MULTIBOOT2_MEMORY_AVAILABLE 1 > +#define MULTIBOOT2_MEMORY_RESERVED 2 > +#define MULTIBOOT2_MEMORY_ACPI_RECLAIMABLE 3 > +#define MULTIBOOT2_MEMORY_NVS 4 > +#define MULTIBOOT2_MEMORY_BADRAM 5 > + > +/* Framebuffer types. */ > +#define MULTIBOOT2_FRAMEBUFFER_TYPE_INDEXED 0 > +#define MULTIBOOT2_FRAMEBUFFER_TYPE_RGB 1 > +#define MULTIBOOT2_FRAMEBUFFER_TYPE_EGA_TEXT 2 > + > +#ifndef __ASSEMBLY__ > +typedef struct { > + u32 total_size; > + u32 reserved; > +} multiboot2_fixed_t; > + > +typedef struct { > + u32 type; > + u32 size; > +} multiboot2_tag_t; > + > +typedef struct { > + u32 type; > + u32 size; > + char string[0]; > +} multiboot2_tag_string_t; > + Which version of the spec are you using? Can you put a URL somewhere in a comment in the source code, probably at the top of this file? The first mb2 spec I can find on google specifies a common tag header as u16 type, u16 flags, u32 size, which is different to these structs here. ~Andrew > +typedef struct { > + u32 type; > + u32 size; > + u32 mem_lower; > + u32 mem_upper; > +} multiboot2_tag_basic_meminfo_t; > + > +typedef struct __packed { > + u64 addr; > + u64 len; > + u32 type; > + u32 zero; > +} multiboot2_memory_map_t; > + > +typedef struct { > + u32 type; > + u32 size; > + u32 entry_size; > + u32 entry_version; > + multiboot2_memory_map_t entries[0]; > +} multiboot2_tag_mmap_t; > + > +typedef struct { > + u32 type; > + u32 size; > + u32 mod_start; > + u32 mod_end; > + char cmdline[0]; > +} multiboot2_tag_module_t; > +#endif /* __ASSEMBLY__ */ > + > +#endif /* __MULTIBOOT2_H__ */