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- /*
- * 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>
- #include <ipxe/console.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 );
-
- /* 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__ ( PHYS_CODE (
- /* Preserve registers */
- "pushal\n\t"
- /* Preserve stack pointer */
- "subl $4, %k0\n\t"
- "movl %%esp, (%k0)\n\t"
- /* Switch to COM32 stack */
- "movl %k0, %%esp\n\t"
- /* Enable interrupts */
- "sti\n\t"
- /* Construct stack frame */
- "pushl %k1\n\t"
- "pushl %k2\n\t"
- "pushl %k3\n\t"
- "pushl %k4\n\t"
- "pushl %k5\n\t"
- "pushl %k6\n\t"
- "pushl $6\n\t"
- /* Call COM32 entry point */
- "movl %k7, %k0\n\t"
- "call *%k0\n\t"
- /* Disable interrupts */
- "cli\n\t"
- /* Restore stack pointer */
- "movl 24(%%esp), %%esp\n\t"
- /* Restore registers */
- "popal\n\t" )
- :
- : "r" ( avail_mem_top ),
- "r" ( virt_to_phys ( com32_cfarcall_wrapper ) ),
- "r" ( virt_to_phys ( com32_farcall_wrapper ) ),
- "r" ( get_fbms() * 1024 - ( COM32_BOUNCE_SEG << 4 ) ),
- "i" ( COM32_BOUNCE_SEG << 4 ),
- "r" ( virt_to_phys ( com32_intcall_wrapper ) ),
- "r" ( virt_to_phys ( image->cmdline ?
- image->cmdline : "" ) ),
- "i" ( 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;
- }
-
- /* Reset console */
- console_reset();
-
- 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,
- };
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