--- /dev/null
+/*
+ * Copyright (C) 2008 Daniel Verkamp <daniel@drv.nu>.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/**
+ * @file
+ *
+ * SYSLINUX COM32 image format
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <errno.h>
+#include <assert.h>
+#include <realmode.h>
+#include <basemem.h>
+#include <comboot.h>
+#include <ipxe/uaccess.h>
+#include <ipxe/image.h>
+#include <ipxe/segment.h>
+#include <ipxe/init.h>
+#include <ipxe/io.h>
+
+/**
+ * Execute COMBOOT image
+ *
+ * @v image COM32 image
+ * @ret rc Return status code
+ */
+static int com32_exec_loop ( struct image *image ) {
+ struct memory_map memmap;
+ unsigned int i;
+ int state;
+ uint32_t avail_mem_top;
+
+ state = rmsetjmp ( comboot_return );
+
+ switch ( state ) {
+ case 0: /* First time through; invoke COM32 program */
+
+ /* Get memory map */
+ get_memmap ( &memmap );
+
+ /* Find end of block covering COM32 image loading area */
+ for ( i = 0, avail_mem_top = 0 ; i < memmap.count ; i++ ) {
+ if ( (memmap.regions[i].start <= COM32_START_PHYS) &&
+ (memmap.regions[i].end > COM32_START_PHYS + image->len) ) {
+ avail_mem_top = memmap.regions[i].end;
+ break;
+ }
+ }
+
+ DBGC ( image, "COM32 %p: available memory top = 0x%x\n",
+ image, avail_mem_top );
+
+ assert ( avail_mem_top != 0 );
+
+ com32_external_esp = phys_to_virt ( avail_mem_top );
+
+ /* Hook COMBOOT API interrupts */
+ hook_comboot_interrupts();
+
+ /* Unregister image, so that a "boot" command doesn't
+ * throw us into an execution loop. We never
+ * reregister ourselves; COMBOOT images expect to be
+ * removed on exit.
+ */
+ unregister_image ( image );
+
+ __asm__ __volatile__ (
+ "movl %%esp, (com32_internal_esp)\n\t" /* Save internal virtual address space ESP */
+ "movl (com32_external_esp), %%esp\n\t" /* Switch to COM32 ESP (top of available memory) */
+ "call _virt_to_phys\n\t" /* Switch to flat physical address space */
+ "sti\n\t" /* Enable interrupts */
+ "pushl %0\n\t" /* Pointer to CDECL helper function */
+ "pushl %1\n\t" /* Pointer to FAR call helper function */
+ "pushl %2\n\t" /* Size of low memory bounce buffer */
+ "pushl %3\n\t" /* Pointer to low memory bounce buffer */
+ "pushl %4\n\t" /* Pointer to INT call helper function */
+ "pushl %5\n\t" /* Pointer to the command line arguments */
+ "pushl $6\n\t" /* Number of additional arguments */
+ "call *%6\n\t" /* Execute image */
+ "cli\n\t" /* Disable interrupts */
+ "call _phys_to_virt\n\t" /* Switch back to internal virtual address space */
+ "movl (com32_internal_esp), %%esp\n\t" /* Switch back to internal stack */
+ :
+ :
+ /* %0 */ "r" ( virt_to_phys ( com32_cfarcall_wrapper ) ),
+ /* %1 */ "r" ( virt_to_phys ( com32_farcall_wrapper ) ),
+ /* %2 */ "r" ( get_fbms() * 1024 - (COM32_BOUNCE_SEG << 4) ),
+ /* %3 */ "i" ( COM32_BOUNCE_SEG << 4 ),
+ /* %4 */ "r" ( virt_to_phys ( com32_intcall_wrapper ) ),
+ /* %5 */ "r" ( virt_to_phys ( image->cmdline ?
+ image->cmdline : "" ) ),
+ /* %6 */ "r" ( COM32_START_PHYS )
+ :
+ "memory" );
+ DBGC ( image, "COM32 %p: returned\n", image );
+ break;
+
+ case COMBOOT_EXIT:
+ DBGC ( image, "COM32 %p: exited\n", image );
+ break;
+
+ case COMBOOT_EXIT_RUN_KERNEL:
+ assert ( image->replacement );
+ DBGC ( image, "COM32 %p: exited to run kernel %s\n",
+ image, image->replacement->name );
+ break;
+
+ case COMBOOT_EXIT_COMMAND:
+ DBGC ( image, "COM32 %p: exited after executing command\n",
+ image );
+ break;
+
+ default:
+ assert ( 0 );
+ break;
+ }
+
+ unhook_comboot_interrupts();
+ comboot_force_text_mode();
+
+ return 0;
+}
+
+/**
+ * Check image name extension
+ *
+ * @v image COM32 image
+ * @ret rc Return status code
+ */
+static int com32_identify ( struct image *image ) {
+ const char *ext;
+ static const uint8_t magic[] = { 0xB8, 0xFF, 0x4C, 0xCD, 0x21 };
+ uint8_t buf[5];
+
+ if ( image->len >= 5 ) {
+ /* Check for magic number
+ * mov eax,21cd4cffh
+ * B8 FF 4C CD 21
+ */
+ copy_from_user ( buf, image->data, 0, sizeof(buf) );
+ if ( ! memcmp ( buf, magic, sizeof(buf) ) ) {
+ DBGC ( image, "COM32 %p: found magic number\n",
+ image );
+ return 0;
+ }
+ }
+
+ /* Magic number not found; check filename extension */
+
+ ext = strrchr( image->name, '.' );
+
+ if ( ! ext ) {
+ DBGC ( image, "COM32 %p: no extension\n",
+ image );
+ return -ENOEXEC;
+ }
+
+ ++ext;
+
+ if ( strcasecmp( ext, "c32" ) ) {
+ DBGC ( image, "COM32 %p: unrecognized extension %s\n",
+ image, ext );
+ return -ENOEXEC;
+ }
+
+ return 0;
+}
+
+
+/**
+ * Load COM32 image into memory
+ * @v image COM32 image
+ * @ret rc Return status code
+ */
+static int com32_load_image ( struct image *image ) {
+ size_t filesz, memsz;
+ userptr_t buffer;
+ int rc;
+
+ filesz = image->len;
+ memsz = filesz;
+ buffer = phys_to_user ( COM32_START_PHYS );
+ if ( ( rc = prep_segment ( buffer, filesz, memsz ) ) != 0 ) {
+ DBGC ( image, "COM32 %p: could not prepare segment: %s\n",
+ image, strerror ( rc ) );
+ return rc;
+ }
+
+ /* Copy image to segment */
+ memcpy_user ( buffer, 0, image->data, 0, filesz );
+
+ return 0;
+}
+
+/**
+ * Prepare COM32 low memory bounce buffer
+ * @v image COM32 image
+ * @ret rc Return status code
+ */
+static int com32_prepare_bounce_buffer ( struct image * image ) {
+ unsigned int seg;
+ userptr_t seg_userptr;
+ size_t filesz, memsz;
+ int rc;
+
+ seg = COM32_BOUNCE_SEG;
+ seg_userptr = real_to_user ( seg, 0 );
+
+ /* Ensure the entire 64k segment is free */
+ memsz = 0xFFFF;
+ filesz = 0;
+
+ /* Prepare, verify, and load the real-mode segment */
+ if ( ( rc = prep_segment ( seg_userptr, filesz, memsz ) ) != 0 ) {
+ DBGC ( image, "COM32 %p: could not prepare bounce buffer segment: %s\n",
+ image, strerror ( rc ) );
+ return rc;
+ }
+
+ return 0;
+}
+
+/**
+ * Probe COM32 image
+ *
+ * @v image COM32 image
+ * @ret rc Return status code
+ */
+static int com32_probe ( struct image *image ) {
+ int rc;
+
+ DBGC ( image, "COM32 %p: name '%s'\n", image, image->name );
+
+ /* Check if this is a COMBOOT image */
+ if ( ( rc = com32_identify ( image ) ) != 0 ) {
+ return rc;
+ }
+
+ return 0;
+}
+
+/**
+ * Execute COMBOOT image
+ *
+ * @v image COM32 image
+ * @ret rc Return status code
+ */
+static int com32_exec ( struct image *image ) {
+ int rc;
+
+ /* Load image */
+ if ( ( rc = com32_load_image ( image ) ) != 0 ) {
+ return rc;
+ }
+
+ /* Prepare bounce buffer segment */
+ if ( ( rc = com32_prepare_bounce_buffer ( image ) ) != 0 ) {
+ return rc;
+ }
+
+ return com32_exec_loop ( image );
+}
+
+/** SYSLINUX COM32 image type */
+struct image_type com32_image_type __image_type ( PROBE_NORMAL ) = {
+ .name = "COM32",
+ .probe = com32_probe,
+ .exec = com32_exec,
+};
Code Review / kvmfornfv.git / blobdiff