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Diffstat (limited to 'contrib/syslinux-4.02/com32/lib/syslinux/load_linux.c')
-rw-r--r--contrib/syslinux-4.02/com32/lib/syslinux/load_linux.c511
1 files changed, 511 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/com32/lib/syslinux/load_linux.c b/contrib/syslinux-4.02/com32/lib/syslinux/load_linux.c
new file mode 100644
index 0000000..df79362
--- /dev/null
+++ b/contrib/syslinux-4.02/com32/lib/syslinux/load_linux.c
@@ -0,0 +1,511 @@
+/* ----------------------------------------------------------------------- *
+ *
+ * Copyright 2007-2009 H. Peter Anvin - All Rights Reserved
+ * Copyright 2009 Intel Corporation; author: H. Peter Anvin
+ *
+ * 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 THE AUTHORS OR COPYRIGHT
+ * HOLDERS 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.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * load_linux.c
+ *
+ * Load a Linux kernel (Image/zImage/bzImage).
+ */
+
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <string.h>
+#include <minmax.h>
+#include <syslinux/align.h>
+#include <syslinux/linux.h>
+#include <syslinux/bootrm.h>
+#include <syslinux/movebits.h>
+
+#ifndef DEBUG
+# define DEBUG 0
+#endif
+#if DEBUG
+# include <stdio.h>
+# define dprintf printf
+#else
+# define dprintf(f, ...) ((void)0)
+#endif
+
+struct linux_header {
+ uint8_t boot_sector_1[0x0020];
+ uint16_t old_cmd_line_magic;
+ uint16_t old_cmd_line_offset;
+ uint8_t boot_sector_2[0x01f1 - 0x0024];
+ uint8_t setup_sects;
+ uint16_t root_flags;
+ uint32_t syssize;
+ uint16_t ram_size;
+ uint16_t vid_mode;
+ uint16_t root_dev;
+ uint16_t boot_flag;
+ uint16_t jump;
+ uint32_t header;
+ uint16_t version;
+ uint32_t realmode_swtch;
+ uint16_t start_sys;
+ uint16_t kernel_version;
+ uint8_t type_of_loader;
+ uint8_t loadflags;
+ uint16_t setup_move_size;
+ uint32_t code32_start;
+ uint32_t ramdisk_image;
+ uint32_t ramdisk_size;
+ uint32_t bootsect_kludge;
+ uint16_t heap_end_ptr;
+ uint16_t pad1;
+ uint32_t cmd_line_ptr;
+ uint32_t initrd_addr_max;
+ uint32_t kernel_alignment;
+ uint8_t relocatable_kernel;
+ uint8_t pad2[3];
+ uint32_t cmdline_max_len;
+} __packed;
+
+#define BOOT_MAGIC 0xAA55
+#define LINUX_MAGIC ('H' + ('d' << 8) + ('r' << 16) + ('S' << 24))
+#define OLD_CMDLINE_MAGIC 0xA33F
+
+/* loadflags */
+#define LOAD_HIGH 0x01
+#define CAN_USE_HEAP 0x80
+
+/* Get a value with a potential suffix (k/m/g/t/p/e) */
+static unsigned long long suffix_number(const char *str)
+{
+ char *ep;
+ unsigned long long v;
+ int shift;
+
+ v = strtoull(str, &ep, 0);
+ switch (*ep | 0x20) {
+ case 'k':
+ shift = 10;
+ break;
+ case 'm':
+ shift = 20;
+ break;
+ case 'g':
+ shift = 30;
+ break;
+ case 't':
+ shift = 40;
+ break;
+ case 'p':
+ shift = 50;
+ break;
+ case 'e':
+ shift = 60;
+ break;
+ default:
+ shift = 0;
+ break;
+ }
+ v <<= shift;
+
+ return v;
+}
+
+/*
+ * Find the last instance of a particular command line argument
+ * (which should include the final =; do not use for boolean arguments)
+ * Note: the resulting string is typically not null-terminated.
+ */
+static const char *find_argument(const char *cmdline, const char *argument)
+{
+ const char *found = NULL;
+ const char *p = cmdline;
+ bool was_space = true;
+ size_t la = strlen(argument);
+
+ while (*p) {
+ if (isspace(*p)) {
+ was_space = true;
+ } else if (was_space) {
+ if (!memcmp(p, argument, la))
+ found = p + la;
+ was_space = false;
+ }
+ p++;
+ }
+
+ return found;
+}
+
+/* Truncate to 32 bits, with saturate */
+static inline uint32_t saturate32(unsigned long long v)
+{
+ return (v > 0xffffffff) ? 0xffffffff : (uint32_t) v;
+}
+
+/* Get the combined size of the initramfs */
+static addr_t initramfs_size(struct initramfs *initramfs)
+{
+ struct initramfs *ip;
+ addr_t size = 0;
+
+ if (!initramfs)
+ return 0;
+
+ for (ip = initramfs->next; ip->len; ip = ip->next) {
+ size = (size + ip->align - 1) & ~(ip->align - 1); /* Alignment */
+ size += ip->len;
+ }
+
+ return size;
+}
+
+/* Create the appropriate mappings for the initramfs */
+static int map_initramfs(struct syslinux_movelist **fraglist,
+ struct syslinux_memmap **mmap,
+ struct initramfs *initramfs, addr_t addr)
+{
+ struct initramfs *ip;
+ addr_t next_addr, len, pad;
+
+ for (ip = initramfs->next; ip->len; ip = ip->next) {
+ len = ip->len;
+ next_addr = addr + len;
+
+ /* If this isn't the last entry, extend the zero-pad region
+ to enforce the alignment of the next chunk. */
+ if (ip->next->len) {
+ pad = -next_addr & (ip->next->align - 1);
+ len += pad;
+ next_addr += pad;
+ }
+
+ if (ip->data_len) {
+ if (syslinux_add_movelist(fraglist, addr, (addr_t) ip->data, len))
+ return -1;
+ }
+ if (len > ip->data_len) {
+ if (syslinux_add_memmap(mmap, addr + ip->data_len,
+ len - ip->data_len, SMT_ZERO))
+ return -1;
+ }
+ addr = next_addr;
+ }
+
+ return 0;
+}
+
+int syslinux_boot_linux(void *kernel_buf, size_t kernel_size,
+ struct initramfs *initramfs, char *cmdline)
+{
+ struct linux_header hdr, *whdr;
+ size_t real_mode_size, prot_mode_size;
+ addr_t real_mode_base, prot_mode_base;
+ addr_t irf_size;
+ size_t cmdline_size, cmdline_offset;
+ struct syslinux_rm_regs regs;
+ struct syslinux_movelist *fraglist = NULL;
+ struct syslinux_memmap *mmap = NULL;
+ struct syslinux_memmap *amap = NULL;
+ bool ok;
+ uint32_t memlimit = 0;
+ uint16_t video_mode = 0;
+ const char *arg;
+
+ cmdline_size = strlen(cmdline) + 1;
+
+ if (kernel_size < 2 * 512)
+ goto bail;
+
+ /* Look for specific command-line arguments we care about */
+ if ((arg = find_argument(cmdline, "mem=")))
+ memlimit = saturate32(suffix_number(arg));
+
+ if ((arg = find_argument(cmdline, "vga="))) {
+ switch (arg[0] | 0x20) {
+ case 'a': /* "ask" */
+ video_mode = 0xfffd;
+ break;
+ case 'e': /* "ext" */
+ video_mode = 0xfffe;
+ break;
+ case 'n': /* "normal" */
+ video_mode = 0xffff;
+ break;
+ case 'c': /* "current" */
+ video_mode = 0x0f04;
+ break;
+ default:
+ video_mode = strtoul(arg, NULL, 0);
+ break;
+ }
+ }
+
+ /* Copy the header into private storage */
+ /* Use whdr to modify the actual kernel header */
+ memcpy(&hdr, kernel_buf, sizeof hdr);
+ whdr = (struct linux_header *)kernel_buf;
+
+ if (hdr.boot_flag != BOOT_MAGIC)
+ goto bail;
+
+ if (hdr.header != LINUX_MAGIC) {
+ hdr.version = 0x0100; /* Very old kernel */
+ hdr.loadflags = 0;
+ }
+
+ whdr->vid_mode = video_mode;
+
+ if (!hdr.setup_sects)
+ hdr.setup_sects = 4;
+
+ if (hdr.version < 0x0203)
+ hdr.initrd_addr_max = 0x37ffffff;
+
+ if (!memlimit && memlimit - 1 > hdr.initrd_addr_max)
+ memlimit = hdr.initrd_addr_max + 1; /* Zero for no limit */
+
+ if (hdr.version < 0x0205 || !(hdr.loadflags & LOAD_HIGH))
+ hdr.relocatable_kernel = 0;
+
+ if (hdr.version < 0x0206)
+ hdr.cmdline_max_len = 256;
+
+ if (cmdline_size > hdr.cmdline_max_len) {
+ cmdline_size = hdr.cmdline_max_len;
+ cmdline[cmdline_size - 1] = '\0';
+ }
+
+ if (hdr.version < 0x0202 || !(hdr.loadflags & 0x01))
+ cmdline_offset = (0x9ff0 - cmdline_size) & ~15;
+ else
+ cmdline_offset = 0x10000;
+
+ real_mode_size = (hdr.setup_sects + 1) << 9;
+ real_mode_base = (hdr.loadflags & LOAD_HIGH) ? 0x10000 : 0x90000;
+ prot_mode_base = (hdr.loadflags & LOAD_HIGH) ? 0x100000 : 0x10000;
+ prot_mode_size = kernel_size - real_mode_size;
+
+ if (!(hdr.loadflags & LOAD_HIGH) && prot_mode_size > 512 * 1024)
+ goto bail; /* Kernel cannot be loaded low */
+
+ if (initramfs && hdr.version < 0x0200)
+ goto bail; /* initrd/initramfs not supported */
+
+ if (hdr.version >= 0x0200) {
+ whdr->type_of_loader = 0x30; /* SYSLINUX unknown module */
+ if (hdr.version >= 0x0201) {
+ whdr->heap_end_ptr = cmdline_offset - 0x0200;
+ whdr->loadflags |= CAN_USE_HEAP;
+ }
+ if (hdr.version >= 0x0202) {
+ whdr->cmd_line_ptr = real_mode_base + cmdline_offset;
+ } else {
+ whdr->old_cmd_line_magic = OLD_CMDLINE_MAGIC;
+ whdr->old_cmd_line_offset = cmdline_offset;
+ /* Be paranoid and round up to a multiple of 16 */
+ whdr->setup_move_size = (cmdline_offset + cmdline_size + 15) & ~15;
+ }
+ }
+
+ /* Get the memory map */
+ mmap = syslinux_memory_map(); /* Memory map for shuffle_boot */
+ amap = syslinux_dup_memmap(mmap); /* Keep track of available memory */
+ if (!mmap || !amap)
+ goto bail;
+
+#if DEBUG
+ dprintf("Initial memory map:\n");
+ syslinux_dump_memmap(stdout, mmap);
+#endif
+
+ /* If the user has specified a memory limit, mark that as unavailable.
+ Question: should we mark this off-limit in the mmap as well (meaning
+ it's unavailable to the boot loader, which probably has already touched
+ some of it), or just in the amap? */
+ if (memlimit)
+ if (syslinux_add_memmap(&amap, memlimit, -memlimit, SMT_RESERVED))
+ goto bail;
+
+ /* Place the kernel in memory */
+
+ /* First, find a suitable place for the protected-mode code */
+ if (syslinux_memmap_type(amap, prot_mode_base, prot_mode_size)
+ != SMT_FREE) {
+ const struct syslinux_memmap *mp;
+ if (!hdr.relocatable_kernel)
+ goto bail; /* Can't relocate - no hope */
+
+ ok = false;
+ for (mp = amap; mp; mp = mp->next) {
+ addr_t start, end;
+ start = mp->start;
+ end = mp->next->start;
+
+ if (mp->type != SMT_FREE)
+ continue;
+
+ if (end <= prot_mode_base)
+ continue; /* Only relocate upwards */
+
+ if (start <= prot_mode_base)
+ start = prot_mode_base;
+
+ start = ALIGN_UP(start, hdr.kernel_alignment);
+ if (start >= end)
+ continue;
+
+ /* The 3* here is a total fudge factor... it's supposed to
+ account for the fact that the kernel needs to be decompressed,
+ and then followed by the BSS and BRK regions. This doesn't,
+ however, account for the fact that the kernel is decompressed
+ into a whole other place, either. */
+ if (end - start >= 3 * prot_mode_size) {
+ whdr->code32_start += start - prot_mode_base;
+ prot_mode_base = start;
+ ok = true;
+ break;
+ }
+ }
+
+ if (!ok)
+ goto bail;
+ }
+
+ /* Real mode code */
+ if (syslinux_memmap_type(amap, real_mode_base,
+ cmdline_offset + cmdline_size) != SMT_FREE) {
+ const struct syslinux_memmap *mp;
+
+ ok = false;
+ for (mp = amap; mp; mp = mp->next) {
+ addr_t start, end;
+ start = mp->start;
+ end = mp->next->start;
+
+ if (mp->type != SMT_FREE)
+ continue;
+
+ if (start < real_mode_base)
+ start = real_mode_base; /* Lowest address we'll use */
+ if (end > 640 * 1024)
+ end = 640 * 1024;
+
+ start = ALIGN_UP(start, 16);
+ if (start > 0x90000 || start >= end)
+ continue;
+
+ if (end - start >= cmdline_offset + cmdline_size) {
+ real_mode_base = start;
+ ok = true;
+ break;
+ }
+ }
+ }
+
+ if (syslinux_add_movelist(&fraglist, real_mode_base, (addr_t) kernel_buf,
+ real_mode_size))
+ goto bail;
+ if (syslinux_add_memmap
+ (&amap, real_mode_base, cmdline_offset + cmdline_size, SMT_ALLOC))
+ goto bail;
+
+ /* Zero region between real mode code and cmdline */
+ if (syslinux_add_memmap(&mmap, real_mode_base + real_mode_size,
+ cmdline_offset - real_mode_size, SMT_ZERO))
+ goto bail;
+
+ /* Command line */
+ if (syslinux_add_movelist(&fraglist, real_mode_base + cmdline_offset,
+ (addr_t) cmdline, cmdline_size))
+ goto bail;
+
+ /* Protected-mode code */
+ if (syslinux_add_movelist(&fraglist, prot_mode_base,
+ (addr_t) kernel_buf + real_mode_size,
+ prot_mode_size))
+ goto bail;
+ if (syslinux_add_memmap(&amap, prot_mode_base, prot_mode_size, SMT_ALLOC))
+ goto bail;
+
+ /* Figure out the size of the initramfs, and where to put it.
+ We should put it at the highest possible address which is
+ <= hdr.initrd_addr_max, which fits the entire initramfs. */
+
+ irf_size = initramfs_size(initramfs); /* Handles initramfs == NULL */
+
+ if (irf_size) {
+ addr_t best_addr = 0;
+ struct syslinux_memmap *ml;
+ const addr_t align_mask = INITRAMFS_MAX_ALIGN - 1;
+
+ if (irf_size) {
+ for (ml = amap; ml->type != SMT_END; ml = ml->next) {
+ addr_t adj_start = (ml->start + align_mask) & ~align_mask;
+ addr_t adj_end = ml->next->start & ~align_mask;
+ if (ml->type == SMT_FREE && adj_end - adj_start >= irf_size)
+ best_addr = (adj_end - irf_size) & ~align_mask;
+ }
+
+ if (!best_addr)
+ goto bail; /* Insufficient memory for initramfs */
+
+ whdr->ramdisk_image = best_addr;
+ whdr->ramdisk_size = irf_size;
+
+ if (syslinux_add_memmap(&amap, best_addr, irf_size, SMT_ALLOC))
+ goto bail;
+
+ if (map_initramfs(&fraglist, &mmap, initramfs, best_addr))
+ goto bail;
+ }
+ }
+
+ /* Set up the registers on entry */
+ memset(&regs, 0, sizeof regs);
+ regs.es = regs.ds = regs.ss = regs.fs = regs.gs = real_mode_base >> 4;
+ regs.cs = (real_mode_base >> 4) + 0x20;
+ /* regs.ip = 0; */
+ /* Linux is OK with sp = 0 = 64K, but perhaps other things aren't... */
+ regs.esp.w[0] = min(cmdline_offset, (size_t) 0xfff0);
+
+#if DEBUG
+ dprintf("Final memory map:\n");
+ syslinux_dump_memmap(stdout, mmap);
+
+ dprintf("Final available map:\n");
+ syslinux_dump_memmap(stdout, amap);
+
+ dprintf("Initial movelist:\n");
+ syslinux_dump_movelist(stdout, fraglist);
+#endif
+
+ syslinux_shuffle_boot_rm(fraglist, mmap, 0, &regs);
+
+bail:
+ syslinux_free_movelist(fraglist);
+ syslinux_free_memmap(mmap);
+ syslinux_free_memmap(amap);
+ return -1;
+}
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