diff options
Diffstat (limited to 'serverboot/default_pager.c')
| -rw-r--r-- | serverboot/default_pager.c | 145 |
1 files changed, 142 insertions, 3 deletions
diff --git a/serverboot/default_pager.c b/serverboot/default_pager.c index 159cd576..dc1e7ff6 100644 --- a/serverboot/default_pager.c +++ b/serverboot/default_pager.c @@ -163,10 +163,14 @@ partition_init() } static partition_t -new_partition (const char *name, struct file_direct *fdp) +new_partition (const char *name, struct file_direct *fdp, + int check_linux_signature) { register partition_t part; register vm_size_t size, bmsize; + vm_offset_t raddr; + mach_msg_type_number_t rsize; + int rc; size = atop(fdp->fd_size * fdp->fd_bsize); bmsize = howmany(size, NB_BM) * sizeof(bm_entry_t); @@ -182,6 +186,138 @@ new_partition (const char *name, struct file_direct *fdp) bzero((char *)part->bitmap, bmsize); + if (check_linux_signature < 0) + return part; + +#define LINUX_PAGE_SIZE 4096 /* size of pages in Linux swap partitions */ + rc = page_read_file_direct(part->file, + 0, LINUX_PAGE_SIZE, + &raddr, + &rsize); + if (rc) + panic("(default pager): cannot read first page of %s! rc=%#x\n", + name, rc); + if (rsize != LINUX_PAGE_SIZE) + panic("(default pager): bad read on first page of %s! size=%u\n", + name, rsize); + if (!memcmp("SWAP-SPACE", (char *) raddr + LINUX_PAGE_SIZE-10, 10)) + { + /* The partition's first page has a Linux swap signature. + This means the beginning of the page contains a bitmap + of good pages, and all others are bad. */ + unsigned int i, j, bad; + printf("(default pager): Found Linux 2.0 swap signature in %s...", + name); + part->bitmap[0] |= 1; /* first page unusable */ + part->free--; + bad = 0; + memset((char *) raddr + LINUX_PAGE_SIZE-10, 0, 10); + for (i = 0; i < LINUX_PAGE_SIZE / sizeof(bm_entry_t); ++i) + { + bm_entry_t bm = ((bm_entry_t *) raddr)[i]; + if (bm == BM_MASK) + continue; + /* There are some zero bits in this word. */ + for (j = 0; j < NB_BM; ++j) + if ((bm & (1 << j)) == 0) + { + ++bad; + part->bitmap[i] |= 1 << j; + } + } + part->free -= bad; + printf ("%dk swap-space (excludes %dk marked bad)\n", + part->free * (LINUX_PAGE_SIZE / 1024), + bad * (LINUX_PAGE_SIZE / 1024)); + if (part->total_size > 8 * LINUX_PAGE_SIZE) + { + unsigned int waste = part->total_size - (8 * LINUX_PAGE_SIZE); + part->free -= waste; + part->total_size -= waste; + printf("\ +(default pager): NOTE: wasting last %dk of %s past Linux max swapfile size\n", + waste * (LINUX_PAGE_SIZE / 1024), name); + } + } + else if (!memcmp("SWAPSPACE2", + (char *) raddr + LINUX_PAGE_SIZE-10, 10)) + { + struct + { + u_int8_t bootbits[1024]; + u_int32_t version; + u_int32_t last_page; + u_int32_t nr_badpages; + u_int32_t padding[125]; + u_int32_t badpages[1]; + } *hdr = (void *) raddr; + + printf("\ +(default pager): Found Linux 2.2 swap signature (v%u) in %s...", + name, hdr->version); + + part->bitmap[0] |= 1; /* first page unusable */ + part->free--; + + switch (hdr->version) + { + default: + if (check_linux_signature) + { + printf ("version %u unknown! SKIPPING %s!\n", + hdr->version, + name); + return 0; + } + else + printf ("version %u unknown! IGNORING SIGNATURE PAGE!" + " %dk swap-space\n", + hdr->version, + part->free * (LINUX_PAGE_SIZE / 1024)); + break; + + case 1: + { + unsigned int waste, i; + if (hdr->last_page > part->total_size) + { + printf ("signature says %uk, partition has only %uk! ", + hdr->last_page * (LINUX_PAGE_SIZE / 1024), + part->total_size * (LINUX_PAGE_SIZE / 1024)); + waste = 0; + } + else + { + waste = part->total_size - hdr->last_page; + part->total_size = hdr->last_page; + } + for (i = 0; i < hdr->nr_badpages; ++i) + { + const u_int32_t bad = hdr->badpages[i]; + part->bitmap[bad / NB_BM] |= 1 << (i % NB_BM); + part->free--; + } + printf ("%uk swap-space", + part->free * (LINUX_PAGE_SIZE / 1024)); + if (hdr->nr_badpages != 0) + printf (" (excludes %uk marked bad)", + hdr->nr_badpages * (LINUX_PAGE_SIZE / 1024)); + if (waste != 0) + printf (" (excludes %uk pages at end of partition)", + waste * (LINUX_PAGE_SIZE / 1024)); + printf ("\n"); + } + } + } + else if (check_linux_signature) + { + part = 0; + printf ("(default pager): " + "Cannot find Linux swap signature page! SKIPPING %s!", + name); + } + vm_deallocate(mach_task_self(), raddr, rsize); + return part; } @@ -192,11 +328,14 @@ new_partition (const char *name, struct file_direct *fdp) */ void create_paging_partition(const char *name, - struct file_direct *fdp, int isa_file) + struct file_direct *fdp, int isa_file, + int linux_signature) { register partition_t part; - part = new_partition (name, fdp); + part = new_partition (name, fdp, linux_signature); + if (!part) + return; mutex_lock(&all_partitions.lock); { |