1 files changed, 567 insertions, 0 deletions

diff --git a/gpxe/src/arch/i386/image/bzimage.c b/gpxe/src/arch/i386/image/bzimage.c
new file mode 100644
index 00000000..ed9d286d
--- /dev/null
+++ b/gpxe/src/arch/i386/image/bzimage.c
@@ -0,0 +1,567 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/**
+ * @file
+ *
+ * Linux bzImage image format
+ *
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <realmode.h>
+#include <bzimage.h>
+#include <gpxe/uaccess.h>
+#include <gpxe/image.h>
+#include <gpxe/segment.h>
+#include <gpxe/init.h>
+#include <gpxe/initrd.h>
+#include <gpxe/cpio.h>
+#include <gpxe/features.h>
+
+FEATURE ( FEATURE_IMAGE, "bzImage", DHCP_EB_FEATURE_BZIMAGE, 1 );
+
+struct image_type bzimage_image_type __image_type ( PROBE_NORMAL );
+
+/**
+ * bzImage load context
+ */
+struct bzimage_load_context {
+	/** Real-mode kernel portion load segment address */
+	unsigned int rm_kernel_seg;
+	/** Real-mode kernel portion load address */
+	userptr_t rm_kernel;
+	/** Real-mode kernel portion file size */
+	size_t rm_filesz;
+	/** Real-mode heap top (offset from rm_kernel) */
+	size_t rm_heap;
+	/** Command line (offset from rm_kernel) */
+	size_t rm_cmdline;
+	/** Real-mode kernel portion total memory size */
+	size_t rm_memsz;
+	/** Non-real-mode kernel portion load address */
+	userptr_t pm_kernel;
+	/** Non-real-mode kernel portion file and memory size */
+	size_t pm_sz;
+};
+
+/**
+ * bzImage execution context
+ */
+struct bzimage_exec_context {
+	/** Real-mode kernel portion load segment address */
+	unsigned int rm_kernel_seg;
+	/** Real-mode kernel portion load address */
+	userptr_t rm_kernel;
+	/** Real-mode heap top (offset from rm_kernel) */
+	size_t rm_heap;
+	/** Command line (offset from rm_kernel) */
+	size_t rm_cmdline;
+	/** Video mode */
+	unsigned int vid_mode;
+	/** Memory limit */
+	uint64_t mem_limit;
+	/** Initrd address */
+	physaddr_t ramdisk_image;
+	/** Initrd size */
+	physaddr_t ramdisk_size;
+};
+
+/**
+ * Parse kernel command line for bootloader parameters
+ *
+ * @v image		bzImage file
+ * @v exec_ctx		Execution context
+ * @v cmdline		Kernel command line
+ * @ret rc		Return status code
+ */
+static int bzimage_parse_cmdline ( struct image *image,
+				   struct bzimage_exec_context *exec_ctx,
+				   const char *cmdline ) {
+	char *vga;
+	char *mem;
+
+	/* Look for "vga=" */
+	if ( ( vga = strstr ( cmdline, "vga=" ) ) ) {
+		vga += 4;
+		if ( strcmp ( vga, "normal" ) == 0 ) {
+			exec_ctx->vid_mode = BZI_VID_MODE_NORMAL;
+		} else if ( strcmp ( vga, "ext" ) == 0 ) {
+			exec_ctx->vid_mode = BZI_VID_MODE_EXT;
+		} else if ( strcmp ( vga, "ask" ) == 0 ) {
+			exec_ctx->vid_mode = BZI_VID_MODE_ASK;
+		} else {
+			exec_ctx->vid_mode = strtoul ( vga, &vga, 0 );
+			if ( *vga && ( *vga != ' ' ) ) {
+				DBGC ( image, "bzImage %p strange \"vga=\""
+				       "terminator '%c'\n", image, *vga );
+			}
+		}
+	}
+
+	/* Look for "mem=" */
+	if ( ( mem = strstr ( cmdline, "mem=" ) ) ) {
+		mem += 4;
+		exec_ctx->mem_limit = strtoul ( mem, &mem, 0 );
+		switch ( *mem ) {
+		case 'G':
+		case 'g':
+			exec_ctx->mem_limit <<= 10;
+		case 'M':
+		case 'm':
+			exec_ctx->mem_limit <<= 10;
+		case 'K':
+		case 'k':
+			exec_ctx->mem_limit <<= 10;
+			break;
+		case '\0':
+		case ' ':
+			break;
+		default:
+			DBGC ( image, "bzImage %p strange \"mem=\" "
+			       "terminator '%c'\n", image, *mem );
+			break;
+		}
+		exec_ctx->mem_limit -= 1;
+	}
+
+	return 0;
+}
+
+/**
+ * Set command line
+ *
+ * @v image		bzImage image
+ * @v exec_ctx		Execution context
+ * @v cmdline		Kernel command line
+ * @ret rc		Return status code
+ */
+static int bzimage_set_cmdline ( struct image *image,
+				 struct bzimage_exec_context *exec_ctx,
+				 const char *cmdline ) {
+	size_t cmdline_len;
+
+	/* Copy command line down to real-mode portion */
+	cmdline_len = ( strlen ( cmdline ) + 1 );
+	if ( cmdline_len > BZI_CMDLINE_SIZE )
+		cmdline_len = BZI_CMDLINE_SIZE;
+	copy_to_user ( exec_ctx->rm_kernel, exec_ctx->rm_cmdline,
+		       cmdline, cmdline_len );
+	DBGC ( image, "bzImage %p command line \"%s\"\n", image, cmdline );
+
+	return 0;
+}
+
+/**
+ * Load initrd
+ *
+ * @v image		bzImage image
+ * @v initrd		initrd image
+ * @v address		Address at which to load, or UNULL
+ * @ret len		Length of loaded image, rounded up to 4 bytes
+ */
+static size_t bzimage_load_initrd ( struct image *image,
+				    struct image *initrd,
+				    userptr_t address ) {
+	char *filename = initrd->cmdline;
+	struct cpio_header cpio;
+        size_t offset = 0;
+
+	/* Ignore images which aren't initrds */
+	if ( initrd->type != &initrd_image_type )
+		return 0;
+
+	/* Create cpio header before non-prebuilt images */
+	if ( filename && filename[0] ) {
+		size_t name_len = ( strlen ( filename ) + 1 );
+
+		DBGC ( image, "bzImage %p inserting initrd %p as %s\n",
+		       image, initrd, filename );
+		memset ( &cpio, '0', sizeof ( cpio ) );
+		memcpy ( cpio.c_magic, CPIO_MAGIC, sizeof ( cpio.c_magic ) );
+		cpio_set_field ( cpio.c_mode, 0100644 );
+		cpio_set_field ( cpio.c_nlink, 1 );
+		cpio_set_field ( cpio.c_filesize, initrd->len );
+		cpio_set_field ( cpio.c_namesize, name_len );
+		if ( address ) {
+			copy_to_user ( address, offset, &cpio,
+				       sizeof ( cpio ) );
+		}
+		offset += sizeof ( cpio );
+		if ( address ) {
+			copy_to_user ( address, offset, filename,
+				       name_len );
+		}
+		offset += name_len;
+		offset = ( ( offset + 0x03 ) & ~0x03 );
+	}
+
+	/* Copy in initrd image body */
+	if ( address ) {
+		DBGC ( image, "bzImage %p has initrd %p at [%lx,%lx)\n",
+		       image, initrd, address, ( address + offset ) );
+		memcpy_user ( address, offset, initrd->data, 0,
+			      initrd->len );
+	}
+	offset += initrd->len;
+
+	offset = ( ( offset + 0x03 ) & ~0x03 );
+	return offset;
+}
+
+/**
+ * Load initrds, if any
+ *
+ * @v image		bzImage image
+ * @v exec_ctx		Execution context
+ * @ret rc		Return status code
+ */
+static int bzimage_load_initrds ( struct image *image,
+				  struct bzimage_exec_context *exec_ctx ) {
+	struct image *initrd;
+	size_t total_len = 0;
+	physaddr_t address;
+	int rc;
+
+	/* Add up length of all initrd images */
+	for_each_image ( initrd ) {
+		total_len += bzimage_load_initrd ( image, initrd, UNULL );
+	}
+
+	/* Give up if no initrd images found */
+	if ( ! total_len )
+		return 0;
+
+	/* Find a suitable start address.  Try 1MB boundaries,
+	 * starting from the downloaded kernel image itself and
+	 * working downwards until we hit an available region.
+	 */
+	for ( address = ( user_to_phys ( image->data, 0 ) & ~0xfffff ) ; ;
+	      address -= 0x100000 ) {
+		/* Check that we're not going to overwrite the
+		 * kernel itself.  This check isn't totally
+		 * accurate, but errs on the side of caution.
+		 */
+		if ( address <= ( BZI_LOAD_HIGH_ADDR + image->len ) ) {
+			DBGC ( image, "bzImage %p could not find a location "
+			       "for initrd\n", image );
+			return -ENOBUFS;
+		}
+		/* Check that we are within the kernel's range */
+		if ( ( address + total_len - 1 ) > exec_ctx->mem_limit )
+			continue;
+		/* Prepare and verify segment */
+		if ( ( rc = prep_segment ( phys_to_user ( address ), 0,
+					   total_len ) ) != 0 )
+			continue;
+		/* Use this address */
+		break;
+	}
+
+	/* Record initrd location */
+	exec_ctx->ramdisk_image = address;
+	exec_ctx->ramdisk_size = total_len;
+
+	/* Construct initrd */
+	DBGC ( image, "bzImage %p constructing initrd at [%lx,%lx)\n",
+	       image, address, ( address + total_len ) );
+	for_each_image ( initrd ) {
+		address += bzimage_load_initrd ( image, initrd,
+						 phys_to_user ( address ) );
+	}
+
+	return 0;
+}
+
+/**
+ * Execute bzImage image
+ *
+ * @v image		bzImage image
+ * @ret rc		Return status code
+ */
+static int bzimage_exec ( struct image *image ) {
+	struct bzimage_exec_context exec_ctx;
+	struct bzimage_header bzhdr;
+	const char *cmdline = ( image->cmdline ? image->cmdline : "" );
+	int rc;
+
+	/* Initialise context */
+	memset ( &exec_ctx, 0, sizeof ( exec_ctx ) );
+
+	/* Retrieve kernel header */
+	exec_ctx.rm_kernel_seg = image->priv.ul;
+	exec_ctx.rm_kernel = real_to_user ( exec_ctx.rm_kernel_seg, 0 );
+	copy_from_user ( &bzhdr, exec_ctx.rm_kernel, BZI_HDR_OFFSET,
+			 sizeof ( bzhdr ) );
+	exec_ctx.rm_cmdline = exec_ctx.rm_heap = 
+		( bzhdr.heap_end_ptr + 0x200 );
+	exec_ctx.vid_mode = bzhdr.vid_mode;
+	if ( bzhdr.version >= 0x0203 ) {
+		exec_ctx.mem_limit = bzhdr.initrd_addr_max;
+	} else {
+		exec_ctx.mem_limit = BZI_INITRD_MAX;
+	}
+
+	/* Parse command line for bootloader parameters */
+	if ( ( rc = bzimage_parse_cmdline ( image, &exec_ctx, cmdline ) ) != 0)
+		return rc;
+
+	/* Store command line */
+	if ( ( rc = bzimage_set_cmdline ( image, &exec_ctx, cmdline ) ) != 0 )
+		return rc;
+
+	/* Load any initrds */
+	if ( ( rc = bzimage_load_initrds ( image, &exec_ctx ) ) != 0 )
+		return rc;
+
+	/* Update and store kernel header */
+	bzhdr.vid_mode = exec_ctx.vid_mode;
+	bzhdr.ramdisk_image = exec_ctx.ramdisk_image;
+	bzhdr.ramdisk_size = exec_ctx.ramdisk_size;
+	copy_to_user ( exec_ctx.rm_kernel, BZI_HDR_OFFSET, &bzhdr,
+		       sizeof ( bzhdr ) );
+
+	/* Prepare for exiting */
+	shutdown();
+
+	DBGC ( image, "bzImage %p jumping to RM kernel at %04x:0000 "
+	       "(stack %04x:%04zx)\n", image,
+	       ( exec_ctx.rm_kernel_seg + 0x20 ),
+	       exec_ctx.rm_kernel_seg, exec_ctx.rm_heap );
+
+	/* Jump to the kernel */
+	__asm__ __volatile__ ( REAL_CODE ( "movw %w0, %%ds\n\t"
+					   "movw %w0, %%es\n\t"
+					   "movw %w0, %%fs\n\t"
+					   "movw %w0, %%gs\n\t"
+					   "movw %w0, %%ss\n\t"
+					   "movw %w1, %%sp\n\t"
+					   "pushw %w2\n\t"
+					   "pushw $0\n\t"
+					   "lret\n\t" )
+			       : : "r" ( exec_ctx.rm_kernel_seg ),
+			           "r" ( exec_ctx.rm_heap ),
+			           "r" ( exec_ctx.rm_kernel_seg + 0x20 ) );
+
+	/* There is no way for the image to return, since we provide
+	 * no return address.
+	 */
+	assert ( 0 );
+
+	return -ECANCELED; /* -EIMPOSSIBLE */
+}
+
+/**
+ * Load and parse bzImage header
+ *
+ * @v image		bzImage file
+ * @v load_ctx		Load context
+ * @v bzhdr		Buffer for bzImage header
+ * @ret rc		Return status code
+ */
+static int bzimage_load_header ( struct image *image,
+				 struct bzimage_load_context *load_ctx,
+				 struct bzimage_header *bzhdr ) {
+
+	/* Sanity check */
+	if ( image->len < ( BZI_HDR_OFFSET + sizeof ( *bzhdr ) ) ) {
+		DBGC ( image, "bzImage %p too short for kernel header\n",
+		       image );
+		return -ENOEXEC;
+	}
+
+	/* Read and verify header */
+	copy_from_user ( bzhdr, image->data, BZI_HDR_OFFSET,
+			 sizeof ( *bzhdr ) );
+	if ( bzhdr->header != BZI_SIGNATURE ) {
+		DBGC ( image, "bzImage %p bad signature %08lx\n",
+		       image, bzhdr->header );
+		return -ENOEXEC;
+	}
+
+	/* We don't support ancient kernels */
+	if ( bzhdr->version < 0x0200 ) {
+		DBGC ( image, "bzImage %p version %04x not supported\n",
+		       image, bzhdr->version );
+		return -ENOTSUP;
+	}
+
+	/* Calculate load address and size of real-mode portion */
+	load_ctx->rm_kernel_seg = 0x1000; /* place RM kernel at 1000:0000 */
+	load_ctx->rm_kernel = real_to_user ( load_ctx->rm_kernel_seg, 0 );
+	load_ctx->rm_filesz =
+		( ( bzhdr->setup_sects ? bzhdr->setup_sects : 4 ) + 1 ) << 9;
+	load_ctx->rm_memsz = BZI_ASSUMED_RM_SIZE;
+	if ( load_ctx->rm_filesz > image->len ) {
+		DBGC ( image, "bzImage %p too short for %zd byte of setup\n",
+		       image, load_ctx->rm_filesz );
+		return -ENOEXEC;
+	}
+
+	/* Calculate load address and size of non-real-mode portion */
+	load_ctx->pm_kernel = ( ( bzhdr->loadflags & BZI_LOAD_HIGH ) ?
+				phys_to_user ( BZI_LOAD_HIGH_ADDR ) :
+				phys_to_user ( BZI_LOAD_LOW_ADDR ) );
+	load_ctx->pm_sz = ( image->len - load_ctx->rm_filesz );
+
+	DBGC ( image, "bzImage %p version %04x RM %#zx bytes PM %#zx bytes\n",
+	       image, bzhdr->version, load_ctx->rm_filesz, load_ctx->pm_sz );
+	return 0;
+}
+
+/**
+ * Load real-mode portion of bzImage
+ *
+ * @v image		bzImage file
+ * @v load_ctx		Load context
+ * @ret rc		Return status code
+ */
+static int bzimage_load_real ( struct image *image,
+			       struct bzimage_load_context *load_ctx ) {
+	int rc;
+
+	/* Allow space for the stack and heap */
+	load_ctx->rm_memsz += BZI_STACK_SIZE;
+	load_ctx->rm_heap = load_ctx->rm_memsz;
+
+	/* Allow space for the command line */
+	load_ctx->rm_cmdline = load_ctx->rm_memsz;
+	load_ctx->rm_memsz += BZI_CMDLINE_SIZE;
+
+	/* Prepare, verify, and load the real-mode segment */
+	if ( ( rc = prep_segment ( load_ctx->rm_kernel, load_ctx->rm_filesz,
+				   load_ctx->rm_memsz ) ) != 0 ) {
+		DBGC ( image, "bzImage %p could not prepare RM segment: %s\n",
+		       image, strerror ( rc ) );
+		return rc;
+	}
+	memcpy_user ( load_ctx->rm_kernel, 0, image->data, 0,
+		      load_ctx->rm_filesz );
+
+	return 0;
+}
+
+/**
+ * Load non-real-mode portion of bzImage
+ *
+ * @v image		bzImage file
+ * @v load_ctx		Load context
+ * @ret rc		Return status code
+ */
+static int bzimage_load_non_real ( struct image *image,
+				   struct bzimage_load_context *load_ctx ) {
+	int rc;
+
+	/* Prepare, verify and load the non-real-mode segment */
+	if ( ( rc = prep_segment ( load_ctx->pm_kernel, load_ctx->pm_sz,
+				   load_ctx->pm_sz ) ) != 0 ) {
+		DBGC ( image, "bzImage %p could not prepare PM segment: %s\n",
+		       image, strerror ( rc ) );
+		return rc;
+	}
+	memcpy_user ( load_ctx->pm_kernel, 0, image->data, load_ctx->rm_filesz,
+		      load_ctx->pm_sz );
+
+	return 0;
+}
+
+/**
+ * Update and store bzImage header
+ *
+ * @v image		bzImage file
+ * @v load_ctx		Load context
+ * @v bzhdr		Original bzImage header
+ * @ret rc		Return status code
+ */
+static int bzimage_write_header ( struct image *image __unused,
+				  struct bzimage_load_context *load_ctx,
+				  struct bzimage_header *bzhdr ) {
+	struct bzimage_cmdline cmdline;
+
+	/* Update the header and copy it into the loaded kernel */
+	bzhdr->type_of_loader = BZI_LOADER_TYPE_GPXE;
+	if ( bzhdr->version >= 0x0201 ) {
+		bzhdr->heap_end_ptr = ( load_ctx->rm_heap - 0x200 );
+		bzhdr->loadflags |= BZI_CAN_USE_HEAP;
+	}
+	if ( bzhdr->version >= 0x0202 ) {
+		bzhdr->cmd_line_ptr = user_to_phys ( load_ctx->rm_kernel,
+						     load_ctx->rm_cmdline );
+	} else {
+		cmdline.magic = BZI_CMDLINE_MAGIC;
+		cmdline.offset = load_ctx->rm_cmdline;
+		copy_to_user ( load_ctx->rm_kernel, BZI_CMDLINE_OFFSET,
+			       &cmdline, sizeof ( cmdline ) );
+		bzhdr->setup_move_size = load_ctx->rm_memsz;
+	}
+	copy_to_user ( load_ctx->rm_kernel, BZI_HDR_OFFSET,
+		       bzhdr, sizeof ( *bzhdr ) );
+
+	return 0;
+}
+
+/**
+ * Load bzImage image into memory
+ *
+ * @v image		bzImage file
+ * @ret rc		Return status code
+ */
+int bzimage_load ( struct image *image ) {
+	struct bzimage_load_context load_ctx;
+	struct bzimage_header bzhdr;
+	int rc;
+
+	/* Initialise context */
+	memset ( &load_ctx, 0, sizeof ( load_ctx ) );
+
+	/* Load and verify header */
+	if ( ( rc = bzimage_load_header ( image, &load_ctx, &bzhdr ) ) != 0 )
+		return rc;
+
+	/* This is a bzImage image, valid or otherwise */
+	if ( ! image->type )
+		image->type = &bzimage_image_type;
+
+	/* Load real-mode portion */
+	if ( ( rc = bzimage_load_real ( image, &load_ctx ) ) != 0 )
+		return rc;
+
+	/* Load non-real-mode portion */
+	if ( ( rc = bzimage_load_non_real ( image, &load_ctx ) ) != 0 )
+		return rc;
+
+	/* Update and write out header */
+	if ( ( rc = bzimage_write_header ( image, &load_ctx, &bzhdr ) ) != 0 )
+		return rc;
+
+	/* Record real-mode segment in image private data field */
+	image->priv.ul = load_ctx.rm_kernel_seg;
+
+	return 0;
+}
+
+/** Linux bzImage image type */
+struct image_type bzimage_image_type __image_type ( PROBE_NORMAL ) = {
+	.name = "bzImage",
+	.load = bzimage_load,
+	.exec = bzimage_exec,
+};