From 7ecb31e60ca5cde8f7649414a0463ff70fbe2865 Mon Sep 17 00:00:00 2001
From: Vladimir Serbinenko <phcoder@gmail.com>
Date: Mon, 18 May 2015 19:07:16 +0200
Subject: [PATCH 2/2] Add multiboot support.

I've been successfully using SeaBIOS as secondary bootloader. In more details
I have GRUB2-as-payload in flash together with coreboot. SeaBIOS binary is on
the HDD and loaded by GRUB when needed. This has an unfortunate consequence
that I have to keep vga oprom in flash even if usually I boot without it. This
patches makes bios.bin.elf multiboot executable with files passed as modules.
Example:

menuentry "SeaBIOS (mb)" --unrestricted {
   root=ahci0,2
   multiboot /bios.bin.elf
   module /vgabios_x230.rom name=pci8086,0166.rom
}

the parameter name= specifies under which name SeaBIOS will see it.

Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
---
 Makefile             |   3 +-
 scripts/layoutrom.py |  16 +++-
 src/Kconfig          |   7 ++
 src/fw/coreboot.c    |   2 +
 src/fw/multiboot.c   | 114 ++++++++++++++++++++++
 src/post.c           |   1 +
 src/romlayout.S      |   3 +-
 src/std/multiboot.h  | 260 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/util.h           |   1 +
 9 files changed, 403 insertions(+), 4 deletions(-)
 create mode 100644 src/fw/multiboot.c
 create mode 100644 src/std/multiboot.h

diff --git a/Makefile b/Makefile
index 3ee61af..f69f1f7 100644
--- a/Makefile
+++ b/Makefile
@@ -42,7 +42,8 @@ SRC32FLAT=$(SRCBOTH) post.c memmap.c malloc.c romfile.c x86.c optionroms.c \
     hw/ahci.c hw/pvscsi.c hw/usb-xhci.c hw/usb-hub.c hw/sdcard.c \
     fw/coreboot.c fw/lzmadecode.c fw/csm.c fw/biostables.c \
     fw/paravirt.c fw/shadow.c fw/pciinit.c fw/smm.c fw/smp.c fw/mtrr.c fw/xen.c \
-    fw/acpi.c fw/mptable.c fw/pirtable.c fw/smbios.c fw/romfile_loader.c
+    fw/acpi.c fw/mptable.c fw/pirtable.c fw/smbios.c fw/romfile_loader.c \
+    fw/multiboot.c
 SRC32SEG=string.c output.c pcibios.c apm.c stacks.c hw/pci.c hw/serialio.c
 DIRS=src src/hw src/fw vgasrc
 
diff --git a/scripts/layoutrom.py b/scripts/layoutrom.py
index dd770fe..b793f33 100755
--- a/scripts/layoutrom.py
+++ b/scripts/layoutrom.py
@@ -356,7 +356,7 @@ def getRelocs(sections, tosection, type=None):
                         and (type is None or reloc.type == type))]
 
 # Output the linker scripts for all required sections.
-def writeLinkerScripts(li, out16, out32seg, out32flat):
+def writeLinkerScripts(li, out16, out32seg, out32flat, mb_section):
     # Write 16bit linker script
     filesections16 = getSectionsFileid(li.sections, '16')
     out = outXRefs(filesections16, useseg=1) + """
@@ -399,6 +399,11 @@ def writeLinkerScripts(li, out16, out32seg, out32flat):
     filesections32flat = getSectionsFileid(li.sections, '32flat')
     out = outXRefs([], exportsyms=li.varlowsyms
                    , forcedelta=li.final_sec32low_start-li.sec32low_start)
+    if mb_section is None:
+        mbstr = ""
+    else:
+        mbstr = "*(%s)" % mb_section
+        sec32all_start -= 12
     out += outXRefs(filesections32flat, exportsyms=[li.entrysym]) + """
     _reloc_min_align = 0x%x ;
     zonefseg_start = 0x%x ;
@@ -415,6 +420,7 @@ def writeLinkerScripts(li, out16, out32seg, out32flat):
     .text code32flat_start : {
 %s
 %s
+%s
         code32flat_end = ABSOLUTE(.) ;
     } :text
 """ % (li.sec32init_align,
@@ -428,6 +434,7 @@ def writeLinkerScripts(li, out16, out32seg, out32flat):
        li.sec32init_start,
        li.sec32init_end,
        sec32all_start,
+       mbstr,
        relocstr,
        outRelSections(li.sections, 'code32flat_start'))
     out = COMMONHEADER + out + COMMONTRAILER + """
@@ -649,6 +656,11 @@ def main():
     anchorsections = [entrysym.section] + [
         section for section in allsections
         if section.name.startswith('.fixedaddr.')]
+    mb_header = symbols['32flat'].get('mb_head')
+    if mb_header is not None:
+        mb_section = mb_header.section.name
+    else:
+        mb_section = None
     keepsections = findReachable(anchorsections, checkKeep, symbols)
     sections = [section for section in allsections if section in keepsections]
 
@@ -685,7 +697,7 @@ def main():
     li.entrysym = entrysym
 
     # Write out linker script files.
-    writeLinkerScripts(li, out16, out32seg, out32flat)
+    writeLinkerScripts(li, out16, out32seg, out32flat, mb_section)
 
 if __name__ == '__main__':
     main()
diff --git a/src/Kconfig b/src/Kconfig
index 45ca59c..385ce49 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -102,6 +102,13 @@ endchoice
         default y
         help
             Support floppy images in coreboot flash.
+    config MULTIBOOT
+        depends on COREBOOT
+        bool "multiboot support"
+        default y
+        help
+            Add multiboot header in bios.bin.raw and accept files supplied
+	    as multiboot modules.
     config ENTRY_EXTRASTACK
         bool "Use internal stack for 16bit interrupt entry points"
         default y
diff --git a/src/fw/coreboot.c b/src/fw/coreboot.c
index 8fd8449..ec09535 100644
--- a/src/fw/coreboot.c
+++ b/src/fw/coreboot.c
@@ -546,6 +546,8 @@ cbfs_payload_setup(void)
             break;
         struct cbfs_romfile_s *cfile;
         cfile = container_of(file, struct cbfs_romfile_s, file);
+	if (!cfile->fhdr)
+	  continue;
         const char *filename = file->name;
         char *desc = znprintf(MAXDESCSIZE, "Payload [%s]", &filename[4]);
         boot_add_cbfs(cfile->fhdr, desc, bootprio_find_named_rom(filename, 0));
diff --git a/src/fw/multiboot.c b/src/fw/multiboot.c
new file mode 100644
index 0000000..7537c6a
--- /dev/null
+++ b/src/fw/multiboot.c
@@ -0,0 +1,114 @@
+#include "block.h" // MAXDESCSIZE
+#include "byteorder.h" // be32_to_cpu
+#include "config.h" // CONFIG_*
+#include "hw/pci.h" // pci_probe_devices
+#include "lzmadecode.h" // LzmaDecode
+#include "malloc.h" // free
+#include "memmap.h" // add_e820
+#include "output.h" // dprintf
+#include "paravirt.h" // PlatformRunningOn
+#include "romfile.h" // romfile_findprefix
+#include "stacks.h" // yield
+#include "string.h" // memset
+#include "util.h" // coreboot_preinit
+#include "std/multiboot.h"
+
+struct mbfs_romfile_s {
+    struct romfile_s file;
+    void *data;
+};
+
+static int
+extract_filename(char *dest, char *src, size_t lim)
+{
+    char *ptr;
+    for (ptr = src; *ptr; ptr++) {
+	if (!(ptr == src || ptr[-1] == ' ' || ptr[-1] == '\t'))
+	    continue;
+	/* memcmp stops early if it encounters \0 as it doesn't match name=.  */
+	if (memcmp(ptr, "name=", 5) == 0) {
+	    int i;
+	    char *optr = dest;
+	    for (i = 0, ptr += 5; *ptr && *ptr != ' ' && i < lim; i++) {
+		*optr++ = *ptr++;
+	    }
+	    *optr++ = '\0';
+	    return 1;
+	}
+    }
+    return 0;
+}
+
+// Copy a file to memory (uncompressing if necessary)
+static int
+mbfs_copyfile(struct romfile_s *file, void *dst, u32 maxlen)
+{
+    if (!CONFIG_COREBOOT_FLASH)
+        return -1;
+
+    struct mbfs_romfile_s *cfile;
+    cfile = container_of(file, struct mbfs_romfile_s, file);
+    u32 size = cfile->file.size;
+    void *src = cfile->data;
+
+    // Not compressed.
+    dprintf(3, "Copying data %d@%p to %d@%p\n", size, src, maxlen, dst);
+    if (size > maxlen) {
+        warn_noalloc();
+        return -1;
+    }
+    iomemcpy(dst, src, size);
+    return size;
+}
+
+u32 __VISIBLE entry_eax, entry_ebx;
+
+void
+multiboot_init(void)
+{
+    struct multiboot_info *mbi;
+    if (!CONFIG_MULTIBOOT)
+	return;
+    dprintf (1, "multiboot: eax=%x, ebx=%x\n", entry_eax, entry_ebx);
+    if (entry_eax != MULTIBOOT_BOOTLOADER_MAGIC)
+	return;
+    mbi = (void *)entry_ebx;
+    dprintf (1, "mbptr=%p\n", mbi);
+    dprintf (1, "flags=0x%x, mods=0x%x, mods_c=%d\n", mbi->flags, mbi->mods_addr,
+	     mbi->mods_count);
+    if (!(mbi->flags & MULTIBOOT_INFO_MODS))
+	return;
+    int i;
+    struct multiboot_mod_list *mod = (void *)mbi->mods_addr;
+    for (i = 0; i < mbi->mods_count; i++) {
+	struct mbfs_romfile_s *cfile;
+	u8 *copy;
+	u32 len;
+	if (!mod[i].cmdline)
+	    continue;
+	len = mod[i].mod_end - mod[i].mod_start;
+	cfile = malloc_tmp(sizeof(*cfile));
+	memset(cfile, 0, sizeof(*cfile));
+	dprintf (1, "module %s, size 0x%x\n", (char *)mod[i].cmdline, len);
+	if (!extract_filename(cfile->file.name, (char *)mod[i].cmdline,
+			      sizeof(cfile->file.name))) {
+	    free (cfile);
+	    continue;
+	}
+	dprintf (1, "assigned file name <%s>\n", cfile->file.name);
+	cfile->file.size = len;
+	copy = malloc_tmp (len);
+	memcpy(copy, (void *)mod[i].mod_start, len);
+	cfile->file.copy = mbfs_copyfile;
+	cfile->data = copy;
+	romfile_add(&cfile->file);
+    }
+}
+
+#if CONFIG_MULTIBOOT
+u32 __attribute__((aligned(4))) __VISIBLE mb_head[] = {
+    MULTIBOOT_HEADER_MAGIC,
+    0,
+    -MULTIBOOT_HEADER_MAGIC
+};
+#endif
diff --git a/src/post.c b/src/post.c
index 9ea5620..8d8d083 100644
--- a/src/post.c
+++ b/src/post.c
@@ -116,6 +116,7 @@ interface_init(void)
     // Setup romfile items.
     qemu_cfg_init();
     coreboot_cbfs_init();
+    multiboot_init();
 
     // Setup ivt/bda/ebda
     ivt_init();
diff --git a/src/romlayout.S b/src/romlayout.S
index 93b6874..9855f4f 100644
--- a/src/romlayout.S
+++ b/src/romlayout.S
@@ -13,7 +13,6 @@
 
         .code16
 
-
 /****************************************************************
  * 16bit / 32bit call trampolines
  ****************************************************************/
@@ -374,6 +373,8 @@ entry_bios32:
 entry_elf:
         cli
         cld
+	movl %eax, entry_eax
+	movl %ebx, entry_ebx
         lidtl (BUILD_BIOS_ADDR + pmode_IDT_info)
         lgdtl (BUILD_BIOS_ADDR + rombios32_gdt_48)
         movl $SEG32_MODE32_DS, %eax
diff --git a/src/std/multiboot.h b/src/std/multiboot.h
new file mode 100644
index 0000000..6c95127
--- /dev/null
+++ b/src/std/multiboot.h
@@ -0,0 +1,260 @@
+/*  multiboot.h - Multiboot header file.  */
+/*  Copyright (C) 1999,2003,2007,2008,2009,2010  Free Software Foundation, Inc.
+ *
+ *  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 MULTIBOOT_HEADER
+#define MULTIBOOT_HEADER 1
+
+/* How many bytes from the start of the file we search for the header.  */
+#define MULTIBOOT_SEARCH			8192
+#define MULTIBOOT_HEADER_ALIGN			4
+
+/* The magic field should contain this.  */
+#define MULTIBOOT_HEADER_MAGIC			0x1BADB002
+
+/* This should be in %eax.  */
+#define MULTIBOOT_BOOTLOADER_MAGIC		0x2BADB002
+
+/* Alignment of multiboot modules.  */
+#define MULTIBOOT_MOD_ALIGN			0x00001000
+
+/* Alignment of the multiboot info structure.  */
+#define MULTIBOOT_INFO_ALIGN			0x00000004
+
+/* Flags set in the 'flags' member of the multiboot header.  */
+
+/* Align all boot modules on i386 page (4KB) boundaries.  */
+#define MULTIBOOT_PAGE_ALIGN			0x00000001
+
+/* Must pass memory information to OS.  */
+#define MULTIBOOT_MEMORY_INFO			0x00000002
+
+/* Must pass video information to OS.  */
+#define MULTIBOOT_VIDEO_MODE			0x00000004
+
+/* This flag indicates the use of the address fields in the header.  */
+#define MULTIBOOT_AOUT_KLUDGE			0x00010000
+
+/* Flags to be set in the 'flags' member of the multiboot info structure.  */
+
+/* is there basic lower/upper memory information? */
+#define MULTIBOOT_INFO_MEMORY			0x00000001
+/* is there a boot device set? */
+#define MULTIBOOT_INFO_BOOTDEV			0x00000002
+/* is the command-line defined? */
+#define MULTIBOOT_INFO_CMDLINE			0x00000004
+/* are there modules to do something with? */
+#define MULTIBOOT_INFO_MODS			0x00000008
+
+/* These next two are mutually exclusive */
+
+/* is there a symbol table loaded? */
+#define MULTIBOOT_INFO_AOUT_SYMS		0x00000010
+/* is there an ELF section header table? */
+#define MULTIBOOT_INFO_ELF_SHDR			0X00000020
+
+/* is there a full memory map? */
+#define MULTIBOOT_INFO_MEM_MAP			0x00000040
+
+/* Is there drive info?  */
+#define MULTIBOOT_INFO_DRIVE_INFO		0x00000080
+
+/* Is there a config table?  */
+#define MULTIBOOT_INFO_CONFIG_TABLE		0x00000100
+
+/* Is there a boot loader name?  */
+#define MULTIBOOT_INFO_BOOT_LOADER_NAME		0x00000200
+
+/* Is there a APM table?  */
+#define MULTIBOOT_INFO_APM_TABLE		0x00000400
+
+/* Is there video information?  */
+#define MULTIBOOT_INFO_VBE_INFO		        0x00000800
+#define MULTIBOOT_INFO_FRAMEBUFFER_INFO	        0x00001000
+
+#ifndef ASM_FILE
+
+typedef unsigned char		multiboot_uint8_t;
+typedef unsigned short		multiboot_uint16_t;
+typedef unsigned int		multiboot_uint32_t;
+typedef unsigned long long	multiboot_uint64_t;
+
+struct multiboot_header
+{
+  /* Must be MULTIBOOT_MAGIC - see above.  */
+  multiboot_uint32_t magic;
+
+  /* Feature flags.  */
+  multiboot_uint32_t flags;
+
+  /* The above fields plus this one must equal 0 mod 2^32. */
+  multiboot_uint32_t checksum;
+
+  /* These are only valid if MULTIBOOT_AOUT_KLUDGE is set.  */
+  multiboot_uint32_t header_addr;
+  multiboot_uint32_t load_addr;
+  multiboot_uint32_t load_end_addr;
+  multiboot_uint32_t bss_end_addr;
+  multiboot_uint32_t entry_addr;
+
+  /* These are only valid if MULTIBOOT_VIDEO_MODE is set.  */
+  multiboot_uint32_t mode_type;
+  multiboot_uint32_t width;
+  multiboot_uint32_t height;
+  multiboot_uint32_t depth;
+};
+
+/* The symbol table for a.out.  */
+struct multiboot_aout_symbol_table
+{
+  multiboot_uint32_t tabsize;
+  multiboot_uint32_t strsize;
+  multiboot_uint32_t addr;
+  multiboot_uint32_t reserved;
+};
+typedef struct multiboot_aout_symbol_table multiboot_aout_symbol_table_t;
+
+/* The section header table for ELF.  */
+struct multiboot_elf_section_header_table
+{
+  multiboot_uint32_t num;
+  multiboot_uint32_t size;
+  multiboot_uint32_t addr;
+  multiboot_uint32_t shndx;
+};
+typedef struct multiboot_elf_section_header_table multiboot_elf_section_header_table_t;
+
+struct multiboot_info
+{
+  /* Multiboot info version number */
+  multiboot_uint32_t flags;
+
+  /* Available memory from BIOS */
+  multiboot_uint32_t mem_lower;
+  multiboot_uint32_t mem_upper;
+
+  /* "root" partition */
+  multiboot_uint32_t boot_device;
+
+  /* Kernel command line */
+  multiboot_uint32_t cmdline;
+
+  /* Boot-Module list */
+  multiboot_uint32_t mods_count;
+  multiboot_uint32_t mods_addr;
+
+  union
+  {
+    multiboot_aout_symbol_table_t aout_sym;
+    multiboot_elf_section_header_table_t elf_sec;
+  } u;
+
+  /* Memory Mapping buffer */
+  multiboot_uint32_t mmap_length;
+  multiboot_uint32_t mmap_addr;
+
+  /* Drive Info buffer */
+  multiboot_uint32_t drives_length;
+  multiboot_uint32_t drives_addr;
+
+  /* ROM configuration table */
+  multiboot_uint32_t config_table;
+
+  /* Boot Loader Name */
+  multiboot_uint32_t boot_loader_name;
+
+  /* APM table */
+  multiboot_uint32_t apm_table;
+
+  /* Video */
+  multiboot_uint32_t vbe_control_info;
+  multiboot_uint32_t vbe_mode_info;
+  multiboot_uint16_t vbe_mode;
+  multiboot_uint16_t vbe_interface_seg;
+  multiboot_uint16_t vbe_interface_off;
+  multiboot_uint16_t vbe_interface_len;
+
+  multiboot_uint64_t framebuffer_addr;
+  multiboot_uint32_t framebuffer_pitch;
+  multiboot_uint32_t framebuffer_width;
+  multiboot_uint32_t framebuffer_height;
+  multiboot_uint8_t framebuffer_bpp;
+#define MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED 0
+#define MULTIBOOT_FRAMEBUFFER_TYPE_RGB     1
+#define MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT	2
+  multiboot_uint8_t framebuffer_type;
+  union
+  {
+    struct
+    {
+      multiboot_uint32_t framebuffer_palette_addr;
+      multiboot_uint16_t framebuffer_palette_num_colors;
+    };
+    struct
+    {
+      multiboot_uint8_t framebuffer_red_field_position;
+      multiboot_uint8_t framebuffer_red_mask_size;
+      multiboot_uint8_t framebuffer_green_field_position;
+      multiboot_uint8_t framebuffer_green_mask_size;
+      multiboot_uint8_t framebuffer_blue_field_position;
+      multiboot_uint8_t framebuffer_blue_mask_size;
+    };
+  };
+};
+typedef struct multiboot_info multiboot_info_t;
+
+struct multiboot_color
+{
+  multiboot_uint8_t red;
+  multiboot_uint8_t green;
+  multiboot_uint8_t blue;
+};
+
+struct multiboot_mmap_entry
+{
+  multiboot_uint32_t size;
+  multiboot_uint64_t addr;
+  multiboot_uint64_t len;
+#define MULTIBOOT_MEMORY_AVAILABLE		1
+#define MULTIBOOT_MEMORY_RESERVED		2
+#define MULTIBOOT_MEMORY_ACPI_RECLAIMABLE       3
+#define MULTIBOOT_MEMORY_NVS                    4
+#define MULTIBOOT_MEMORY_BADRAM                 5
+  multiboot_uint32_t type;
+} __attribute__((packed));
+typedef struct multiboot_mmap_entry multiboot_memory_map_t;
+
+struct multiboot_mod_list
+{
+  /* the memory used goes from bytes 'mod_start' to 'mod_end-1' inclusive */
+  multiboot_uint32_t mod_start;
+  multiboot_uint32_t mod_end;
+
+  /* Module command line */
+  multiboot_uint32_t cmdline;
+
+  /* padding to take it to 16 bytes (must be zero) */
+  multiboot_uint32_t pad;
+};
+typedef struct multiboot_mod_list multiboot_module_t;
+
+#endif /* ! ASM_FILE */
+
+#endif /* ! MULTIBOOT_HEADER */
diff --git a/src/util.h b/src/util.h
index 09bb8a9..7f75aa2 100644
--- a/src/util.h
+++ b/src/util.h
@@ -89,6 +89,7 @@ void coreboot_platform_setup(void);
 void cbfs_payload_setup(void);
 void coreboot_preinit(void);
 void coreboot_cbfs_init(void);
+void multiboot_init(void);
 struct cb_header;
 void *find_cb_subtable(struct cb_header *cbh, u32 tag);
 struct cb_header *find_cb_table(void);
-- 
2.1.4

