root/arch/powerpc/boot/main.c

DEFINITIONS

1. prep_kernel
2. prep_initrd
3. prep_esm_blob
4. prep_esm_blob
5. prep_cmdline
6. start

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) Paul Mackerras 1997.
   4  *
   5  * Updates for PPC64 by Todd Inglett, Dave Engebretsen & Peter Bergner.
   6  */
   7 #include <stdarg.h>
   8 #include <stddef.h>
   9 #include "elf.h"
  10 #include "page.h"
  11 #include "string.h"
  12 #include "stdio.h"
  13 #include "ops.h"
  14 #include "reg.h"
  15 
  16 struct addr_range {
  17         void *addr;
  18         unsigned long size;
  19 };
  20 
  21 #undef DEBUG
  22 
  23 static struct addr_range prep_kernel(void)
  24 {
  25         char elfheader[256];
  26         unsigned char *vmlinuz_addr = (unsigned char *)_vmlinux_start;
  27         unsigned long vmlinuz_size = _vmlinux_end - _vmlinux_start;
  28         void *addr = 0;
  29         struct elf_info ei;
  30         long len;
  31         int uncompressed_image = 0;
  32 
  33         len = partial_decompress(vmlinuz_addr, vmlinuz_size,
  34                 elfheader, sizeof(elfheader), 0);
  35         /* assume uncompressed data if -1 is returned */
  36         if (len == -1) {
  37                 uncompressed_image = 1;
  38                 memcpy(elfheader, vmlinuz_addr, sizeof(elfheader));
  39                 printf("No valid compressed data found, assume uncompressed data\n\r");
  40         }
  41 
  42         if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei))
  43                 fatal("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
  44 
  45         if (platform_ops.image_hdr)
  46                 platform_ops.image_hdr(elfheader);
  47 
  48         /* We need to alloc the memsize: gzip will expand the kernel
  49          * text/data, then possible rubbish we don't care about. But
  50          * the kernel bss must be claimed (it will be zero'd by the
  51          * kernel itself)
  52          */
  53         printf("Allocating 0x%lx bytes for kernel...\n\r", ei.memsize);
  54 
  55         if (platform_ops.vmlinux_alloc) {
  56                 addr = platform_ops.vmlinux_alloc(ei.memsize);
  57         } else {
  58                 /*
  59                  * Check if the kernel image (without bss) would overwrite the
  60                  * bootwrapper. The device tree has been moved in fdt_init()
  61                  * to an area allocated with malloc() (somewhere past _end).
  62                  */
  63                 if ((unsigned long)_start < ei.loadsize)
  64                         fatal("Insufficient memory for kernel at address 0!"
  65                                " (_start=%p, uncompressed size=%08lx)\n\r",
  66                                _start, ei.loadsize);
  67 
  68                 if ((unsigned long)_end < ei.memsize)
  69                         fatal("The final kernel image would overwrite the "
  70                                         "device tree\n\r");
  71         }
  72 
  73         if (uncompressed_image) {
  74                 memcpy(addr, vmlinuz_addr + ei.elfoffset, ei.loadsize);
  75                 printf("0x%lx bytes of uncompressed data copied\n\r",
  76                        ei.loadsize);
  77                 goto out;
  78         }
  79 
  80         /* Finally, decompress the kernel */
  81         printf("Decompressing (0x%p <- 0x%p:0x%p)...\n\r", addr,
  82                vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
  83 
  84         len = partial_decompress(vmlinuz_addr, vmlinuz_size,
  85                 addr, ei.loadsize, ei.elfoffset);
  86 
  87         if (len < 0)
  88                 fatal("Decompression failed with error code %ld\n\r", len);
  89 
  90         if (len != ei.loadsize)
  91                  fatal("Decompression error: got 0x%lx bytes, expected 0x%lx.\n\r",
  92                          len, ei.loadsize);
  93 
  94         printf("Done! Decompressed 0x%lx bytes\n\r", len);
  95 out:
  96         flush_cache(addr, ei.loadsize);
  97 
  98         return (struct addr_range){addr, ei.memsize};
  99 }
 100 
 101 static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
 102                                      unsigned long initrd_addr,
 103                                      unsigned long initrd_size)
 104 {
 105         /* If we have an image attached to us, it overrides anything
 106          * supplied by the loader. */
 107         if (_initrd_end > _initrd_start) {
 108                 printf("Attached initrd image at 0x%p-0x%p\n\r",
 109                        _initrd_start, _initrd_end);
 110                 initrd_addr = (unsigned long)_initrd_start;
 111                 initrd_size = _initrd_end - _initrd_start;
 112         } else if (initrd_size > 0) {
 113                 printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
 114                        initrd_addr, initrd_addr + initrd_size);
 115         }
 116 
 117         /* If there's no initrd at all, we're done */
 118         if (! initrd_size)
 119                 return (struct addr_range){0, 0};
 120 
 121         /*
 122          * If the initrd is too low it will be clobbered when the
 123          * kernel relocates to its final location.  In this case,
 124          * allocate a safer place and move it.
 125          */
 126         if (initrd_addr < vmlinux.size) {
 127                 void *old_addr = (void *)initrd_addr;
 128 
 129                 printf("Allocating 0x%lx bytes for initrd ...\n\r",
 130                        initrd_size);
 131                 initrd_addr = (unsigned long)malloc(initrd_size);
 132                 if (! initrd_addr)
 133                         fatal("Can't allocate memory for initial "
 134                                "ramdisk !\n\r");
 135                 printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
 136                        initrd_addr, old_addr, initrd_size);
 137                 memmove((void *)initrd_addr, old_addr, initrd_size);
 138         }
 139 
 140         printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
 141 
 142         /* Tell the kernel initrd address via device tree */
 143         setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
 144         setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
 145 
 146         return (struct addr_range){(void *)initrd_addr, initrd_size};
 147 }
 148 
 149 #ifdef __powerpc64__
 150 static void prep_esm_blob(struct addr_range vmlinux, void *chosen)
 151 {
 152         unsigned long esm_blob_addr, esm_blob_size;
 153 
 154         /* Do we have an ESM (Enter Secure Mode) blob? */
 155         if (_esm_blob_end <= _esm_blob_start)
 156                 return;
 157 
 158         printf("Attached ESM blob at 0x%p-0x%p\n\r",
 159                _esm_blob_start, _esm_blob_end);
 160         esm_blob_addr = (unsigned long)_esm_blob_start;
 161         esm_blob_size = _esm_blob_end - _esm_blob_start;
 162 
 163         /*
 164          * If the ESM blob is too low it will be clobbered when the
 165          * kernel relocates to its final location.  In this case,
 166          * allocate a safer place and move it.
 167          */
 168         if (esm_blob_addr < vmlinux.size) {
 169                 void *old_addr = (void *)esm_blob_addr;
 170 
 171                 printf("Allocating 0x%lx bytes for esm_blob ...\n\r",
 172                        esm_blob_size);
 173                 esm_blob_addr = (unsigned long)malloc(esm_blob_size);
 174                 if (!esm_blob_addr)
 175                         fatal("Can't allocate memory for ESM blob !\n\r");
 176                 printf("Relocating ESM blob 0x%lx <- 0x%p (0x%lx bytes)\n\r",
 177                        esm_blob_addr, old_addr, esm_blob_size);
 178                 memmove((void *)esm_blob_addr, old_addr, esm_blob_size);
 179         }
 180 
 181         /* Tell the kernel ESM blob address via device tree. */
 182         setprop_val(chosen, "linux,esm-blob-start", (u32)(esm_blob_addr));
 183         setprop_val(chosen, "linux,esm-blob-end", (u32)(esm_blob_addr + esm_blob_size));
 184 }
 185 #else
 186 static inline void prep_esm_blob(struct addr_range vmlinux, void *chosen) { }
 187 #endif
 188 
 189 /* A buffer that may be edited by tools operating on a zImage binary so as to
 190  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
 191  * The buffer is put in it's own section so that tools may locate it easier.
 192  */
 193 static char cmdline[BOOT_COMMAND_LINE_SIZE]
 194         __attribute__((__section__("__builtin_cmdline")));
 195 
 196 static void prep_cmdline(void *chosen)
 197 {
 198         unsigned int getline_timeout = 5000;
 199         int v;
 200         int n;
 201 
 202         /* Wait-for-input time */
 203         n = getprop(chosen, "linux,cmdline-timeout", &v, sizeof(v));
 204         if (n == sizeof(v))
 205                 getline_timeout = v;
 206 
 207         if (cmdline[0] == '\0')
 208                 getprop(chosen, "bootargs", cmdline, BOOT_COMMAND_LINE_SIZE-1);
 209 
 210         printf("\n\rLinux/PowerPC load: %s", cmdline);
 211 
 212         /* If possible, edit the command line */
 213         if (console_ops.edit_cmdline && getline_timeout)
 214                 console_ops.edit_cmdline(cmdline, BOOT_COMMAND_LINE_SIZE, getline_timeout);
 215 
 216         printf("\n\r");
 217 
 218         /* Put the command line back into the devtree for the kernel */
 219         setprop_str(chosen, "bootargs", cmdline);
 220 }
 221 
 222 struct platform_ops platform_ops;
 223 struct dt_ops dt_ops;
 224 struct console_ops console_ops;
 225 struct loader_info loader_info;
 226 
 227 void start(void)
 228 {
 229         struct addr_range vmlinux, initrd;
 230         kernel_entry_t kentry;
 231         unsigned long ft_addr = 0;
 232         void *chosen;
 233 
 234         /* Do this first, because malloc() could clobber the loader's
 235          * command line.  Only use the loader command line if a
 236          * built-in command line wasn't set by an external tool */
 237         if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
 238                 memmove(cmdline, loader_info.cmdline,
 239                         min(loader_info.cmdline_len, BOOT_COMMAND_LINE_SIZE-1));
 240 
 241         if (console_ops.open && (console_ops.open() < 0))
 242                 exit();
 243         if (platform_ops.fixups)
 244                 platform_ops.fixups();
 245 
 246         printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 247                _start, get_sp());
 248 
 249         /* Ensure that the device tree has a /chosen node */
 250         chosen = finddevice("/chosen");
 251         if (!chosen)
 252                 chosen = create_node(NULL, "chosen");
 253 
 254         vmlinux = prep_kernel();
 255         initrd = prep_initrd(vmlinux, chosen,
 256                              loader_info.initrd_addr, loader_info.initrd_size);
 257         prep_esm_blob(vmlinux, chosen);
 258         prep_cmdline(chosen);
 259 
 260         printf("Finalizing device tree...");
 261         if (dt_ops.finalize)
 262                 ft_addr = dt_ops.finalize();
 263         if (ft_addr)
 264                 printf(" flat tree at 0x%lx\n\r", ft_addr);
 265         else
 266                 printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
 267 
 268         if (console_ops.close)
 269                 console_ops.close();
 270 
 271         kentry = (kernel_entry_t) vmlinux.addr;
 272         if (ft_addr) {
 273                 if(platform_ops.kentry)
 274                         platform_ops.kentry(ft_addr, vmlinux.addr);
 275                 else
 276                         kentry(ft_addr, 0, NULL);
 277         }
 278         else
 279                 kentry((unsigned long)initrd.addr, initrd.size,
 280                        loader_info.promptr);
 281 
 282         /* console closed so printf in fatal below may not work */
 283         fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
 284 }