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Diffstat (limited to 'pc-bios/s390-ccw/bootmap.c')
-rw-r--r--pc-bios/s390-ccw/bootmap.c455
1 files changed, 312 insertions, 143 deletions
diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
index a2137449dc..56f2f75640 100644
--- a/pc-bios/s390-ccw/bootmap.c
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -8,7 +8,8 @@
  * directory.
  */
 
-#include "libc.h"
+#include <string.h>
+#include <stdio.h>
 #include "s390-ccw.h"
 #include "s390-arch.h"
 #include "bootmap.h"
@@ -21,7 +22,7 @@
 
 #ifdef DEBUG_FALLBACK
 #define dputs(txt) \
-    do { sclp_print("zipl: " txt); } while (0)
+    do { printf("zipl: " txt); } while (0)
 #else
 #define dputs(fmt, ...) \
     do { } while (0)
@@ -61,15 +62,34 @@ static void *s2_prev_blk = _s2;
 static void *s2_cur_blk = _s2 + MAX_SECTOR_SIZE;
 static void *s2_next_blk = _s2 + MAX_SECTOR_SIZE * 2;
 
-static inline void verify_boot_info(BootInfo *bip)
+static inline int verify_boot_info(BootInfo *bip)
 {
-    IPL_assert(magic_match(bip->magic, ZIPL_MAGIC), "No zIPL sig in BootInfo");
-    IPL_assert(bip->version == BOOT_INFO_VERSION, "Wrong zIPL version");
-    IPL_assert(bip->bp_type == BOOT_INFO_BP_TYPE_IPL, "DASD is not for IPL");
-    IPL_assert(bip->dev_type == BOOT_INFO_DEV_TYPE_ECKD, "DASD is not ECKD");
-    IPL_assert(bip->flags == BOOT_INFO_FLAGS_ARCH, "Not for this arch");
-    IPL_assert(block_size_ok(bip->bp.ipl.bm_ptr.eckd.bptr.size),
-               "Bad block size in zIPL section of the 1st record.");
+    if (!magic_match(bip->magic, ZIPL_MAGIC)) {
+        puts("No zIPL sig in BootInfo");
+        return -EINVAL;
+    }
+    if (bip->version != BOOT_INFO_VERSION) {
+        puts("Wrong zIPL version");
+        return -EINVAL;
+    }
+    if (bip->bp_type != BOOT_INFO_BP_TYPE_IPL) {
+        puts("DASD is not for IPL");
+        return -ENODEV;
+    }
+    if (bip->dev_type != BOOT_INFO_DEV_TYPE_ECKD) {
+        puts("DASD is not ECKD");
+        return -ENODEV;
+    }
+    if (bip->flags != BOOT_INFO_FLAGS_ARCH) {
+        puts("Not for this arch");
+        return -EINVAL;
+    }
+    if (!block_size_ok(bip->bp.ipl.bm_ptr.eckd.bptr.size)) {
+        puts("Bad block size in zIPL section of 1st record");
+        return -EINVAL;
+    }
+
+    return 0;
 }
 
 static void eckd_format_chs(ExtEckdBlockPtr *ptr,  bool ldipl,
@@ -144,14 +164,17 @@ static block_number_t load_eckd_segments(block_number_t blk, bool ldipl,
     bool more_data;
 
     memset(_bprs, FREE_SPACE_FILLER, sizeof(_bprs));
-    read_block(blk, bprs, "BPRS read failed");
+    if (virtio_read(blk, bprs)) {
+        puts("BPRS read failed");
+        return ERROR_BLOCK_NR;
+    }
 
     do {
         more_data = false;
         for (j = 0;; j++) {
             block_nr = gen_eckd_block_num(&bprs[j].xeckd, ldipl);
             if (is_null_block_number(block_nr)) { /* end of chunk */
-                break;
+                return NULL_BLOCK_NR;
             }
 
             /* we need the updated blockno for the next indirect entry
@@ -162,15 +185,20 @@ static block_number_t load_eckd_segments(block_number_t blk, bool ldipl,
             }
 
             /* List directed pointer does not store block size */
-            IPL_assert(ldipl || block_size_ok(bprs[j].xeckd.bptr.size),
-                       "bad chunk block size");
+            if (!ldipl && !block_size_ok(bprs[j].xeckd.bptr.size)) {
+                puts("Bad chunk block size");
+                return ERROR_BLOCK_NR;
+            }
 
             if (!eckd_valid_address(&bprs[j].xeckd, ldipl)) {
                 /*
                  * If an invalid address is found during LD-IPL then break and
-                 * retry as CCW
+                 * retry as CCW-IPL, otherwise abort on error
                  */
-                IPL_assert(ldipl, "bad chunk ECKD addr");
+                if (!ldipl) {
+                    puts("Bad chunk ECKD address");
+                    return ERROR_BLOCK_NR;
+                }
                 break;
             }
 
@@ -188,7 +216,10 @@ static block_number_t load_eckd_segments(block_number_t blk, bool ldipl,
                  * I.e. the next ptr must point to the unused memory area
                  */
                 memset(_bprs, FREE_SPACE_FILLER, sizeof(_bprs));
-                read_block(block_nr, bprs, "BPRS continuation read failed");
+                if (virtio_read(block_nr, bprs)) {
+                    puts("BPRS continuation read failed");
+                    return ERROR_BLOCK_NR;
+                }
                 more_data = true;
                 break;
             }
@@ -197,7 +228,10 @@ static block_number_t load_eckd_segments(block_number_t blk, bool ldipl,
              * to memory (address).
              */
             rc = virtio_read_many(block_nr, (void *)(*address), count + 1);
-            IPL_assert(rc == 0, "code chunk read failed");
+            if (rc != 0) {
+                puts("Code chunk read failed");
+                return ERROR_BLOCK_NR;
+            }
 
             *address += (count + 1) * virtio_get_block_size();
         }
@@ -231,7 +265,10 @@ static int eckd_get_boot_menu_index(block_number_t s1b_block_nr)
 
     /* Get Stage1b data */
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
-    read_block(s1b_block_nr, s1b, "Cannot read stage1b boot loader");
+    if (virtio_read(s1b_block_nr, s1b)) {
+        puts("Cannot read stage1b boot loader");
+        return -EIO;
+    }
 
     memset(_s2, FREE_SPACE_FILLER, sizeof(_s2));
 
@@ -243,7 +280,10 @@ static int eckd_get_boot_menu_index(block_number_t s1b_block_nr)
             break;
         }
 
-        read_block(cur_block_nr, s2_cur_blk, "Cannot read stage2 boot loader");
+        if (virtio_read(cur_block_nr, s2_cur_blk)) {
+            puts("Cannot read stage2 boot loader");
+            return -EIO;
+        }
 
         if (find_zipl_boot_menu_banner(&banner_offset)) {
             /*
@@ -251,8 +291,10 @@ static int eckd_get_boot_menu_index(block_number_t s1b_block_nr)
              * possibility of menu data spanning multiple blocks.
              */
             if (prev_block_nr) {
-                read_block(prev_block_nr, s2_prev_blk,
-                           "Cannot read stage2 boot loader");
+                if (virtio_read(prev_block_nr, s2_prev_blk)) {
+                    puts("Cannot read stage2 boot loader");
+                    return -EIO;
+                }
             }
 
             if (i + 1 < STAGE2_BLK_CNT_MAX) {
@@ -260,8 +302,10 @@ static int eckd_get_boot_menu_index(block_number_t s1b_block_nr)
             }
 
             if (next_block_nr && !is_null_block_number(next_block_nr)) {
-                read_block(next_block_nr, s2_next_blk,
-                           "Cannot read stage2 boot loader");
+                if (virtio_read(next_block_nr, s2_next_blk)) {
+                    puts("Cannot read stage2 boot loader");
+                    return -EIO;
+                }
             }
 
             return menu_get_zipl_boot_index(s2_cur_blk + banner_offset);
@@ -270,11 +314,11 @@ static int eckd_get_boot_menu_index(block_number_t s1b_block_nr)
         prev_block_nr = cur_block_nr;
     }
 
-    sclp_print("No zipl boot menu data found. Booting default entry.");
+    printf("No zipl boot menu data found. Booting default entry.");
     return 0;
 }
 
-static void run_eckd_boot_script(block_number_t bmt_block_nr,
+static int run_eckd_boot_script(block_number_t bmt_block_nr,
                                  block_number_t s1b_block_nr)
 {
     int i;
@@ -291,17 +335,28 @@ static void run_eckd_boot_script(block_number_t bmt_block_nr,
     }
 
     debug_print_int("loadparm", loadparm);
-    IPL_assert(loadparm < MAX_BOOT_ENTRIES, "loadparm value greater than"
-               " maximum number of boot entries allowed");
+    if (loadparm >= MAX_BOOT_ENTRIES) {
+        puts("loadparm value greater than max number of boot entries allowed");
+        return -EINVAL;
+    }
 
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
-    read_block(bmt_block_nr, sec, "Cannot read Boot Map Table");
+    if (virtio_read(bmt_block_nr, sec)) {
+        puts("Cannot read Boot Map Table");
+        return -EIO;
+    }
 
     block_nr = gen_eckd_block_num(&bmt->entry[loadparm].xeckd, ldipl);
-    IPL_assert(block_nr != -1, "Cannot find Boot Map Table Entry");
+    if (block_nr == NULL_BLOCK_NR) {
+        puts("Cannot find Boot Map Table Entry");
+        return -EIO;
+    }
 
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
-    read_block(block_nr, sec, "Cannot read Boot Map Script");
+    if (virtio_read(block_nr, sec)) {
+        puts("Cannot read Boot Map Script");
+        return -EIO;
+    }
 
     for (i = 0; bms->entry[i].type == BOOT_SCRIPT_LOAD ||
                 bms->entry[i].type == BOOT_SCRIPT_SIGNATURE; i++) {
@@ -316,21 +371,27 @@ static void run_eckd_boot_script(block_number_t bmt_block_nr,
 
         do {
             block_nr = load_eckd_segments(block_nr, ldipl, &address);
-        } while (block_nr != -1);
+            if (block_nr == ERROR_BLOCK_NR) {
+                return ldipl ? 0 : -EIO;
+            }
+        } while (block_nr != NULL_BLOCK_NR);
     }
 
     if (ldipl && bms->entry[i].type != BOOT_SCRIPT_EXEC) {
         /* Abort LD-IPL and retry as CCW-IPL */
-        return;
+        return 0;
     }
 
-    IPL_assert(bms->entry[i].type == BOOT_SCRIPT_EXEC,
-               "Unknown script entry type");
-    write_reset_psw(bms->entry[i].address.load_address); /* no return */
-    jump_to_IPL_code(0); /* no return */
+    if (bms->entry[i].type != BOOT_SCRIPT_EXEC) {
+        puts("Unknown script entry type");
+        return -EINVAL;
+    }
+    write_reset_psw(bms->entry[i].address.load_address);
+    jump_to_IPL_code(0);
+    return -1;
 }
 
-static void ipl_eckd_cdl(void)
+static int ipl_eckd_cdl(void)
 {
     XEckdMbr *mbr;
     EckdCdlIpl2 *ipl2 = (void *)sec;
@@ -338,23 +399,26 @@ static void ipl_eckd_cdl(void)
     block_number_t bmt_block_nr, s1b_block_nr;
 
     /* we have just read the block #0 and recognized it as "IPL1" */
-    sclp_print("CDL\n");
+    puts("CDL");
 
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
-    read_block(1, ipl2, "Cannot read IPL2 record at block 1");
+    if (virtio_read(1, ipl2)) {
+        puts("Cannot read IPL2 record at block 1");
+        return -EIO;
+    }
 
     mbr = &ipl2->mbr;
     if (!magic_match(mbr, ZIPL_MAGIC)) {
-        sclp_print("No zIPL section in IPL2 record.\n");
-        return;
+        puts("No zIPL section in IPL2 record.");
+        return 0;
     }
     if (!block_size_ok(mbr->blockptr.xeckd.bptr.size)) {
-        sclp_print("Bad block size in zIPL section of IPL2 record.\n");
-        return;
+        puts("Bad block size in zIPL section of IPL2 record.");
+        return 0;
     }
     if (mbr->dev_type != DEV_TYPE_ECKD) {
-        sclp_print("Non-ECKD device type in zIPL section of IPL2 record.\n");
-        return;
+        puts("Non-ECKD device type in zIPL section of IPL2 record.");
+        return 0;
     }
 
     /* save pointer to Boot Map Table */
@@ -364,19 +428,21 @@ static void ipl_eckd_cdl(void)
     s1b_block_nr = eckd_block_num(&ipl2->stage1.seek[0].chs);
 
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
-    read_block(2, vlbl, "Cannot read Volume Label at block 2");
+    if (virtio_read(2, vlbl)) {
+        puts("Cannot read Volume Label at block 2");
+        return -EIO;
+    }
     if (!magic_match(vlbl->key, VOL1_MAGIC)) {
-        sclp_print("Invalid magic of volume label block.\n");
-        return;
+        puts("Invalid magic of volume label block.");
+        return 0;
     }
     if (!magic_match(vlbl->f.key, VOL1_MAGIC)) {
-        sclp_print("Invalid magic of volser block.\n");
-        return;
+        puts("Invalid magic of volser block.");
+        return 0;
     }
     print_volser(vlbl->f.volser);
 
-    run_eckd_boot_script(bmt_block_nr, s1b_block_nr);
-    /* no return */
+    return run_eckd_boot_script(bmt_block_nr, s1b_block_nr);
 }
 
 static void print_eckd_ldl_msg(ECKD_IPL_mode_t mode)
@@ -384,8 +450,8 @@ static void print_eckd_ldl_msg(ECKD_IPL_mode_t mode)
     LDL_VTOC *vlbl = (void *)sec; /* already read, 3rd block */
     char msg[4] = { '?', '.', '\n', '\0' };
 
-    sclp_print((mode == ECKD_CMS) ? "CMS" : "LDL");
-    sclp_print(" version ");
+    printf((mode == ECKD_CMS) ? "CMS" : "LDL");
+    printf(" version ");
     switch (vlbl->LDL_version) {
     case LDL1_VERSION:
         msg[0] = '1';
@@ -398,11 +464,11 @@ static void print_eckd_ldl_msg(ECKD_IPL_mode_t mode)
         msg[1] = '?';
         break;
     }
-    sclp_print(msg);
+    printf("%s", msg);
     print_volser(vlbl->volser);
 }
 
-static void ipl_eckd_ldl(ECKD_IPL_mode_t mode)
+static int ipl_eckd_ldl(ECKD_IPL_mode_t mode)
 {
     block_number_t bmt_block_nr, s1b_block_nr;
     EckdLdlIpl1 *ipl1 = (void *)sec;
@@ -414,12 +480,15 @@ static void ipl_eckd_ldl(ECKD_IPL_mode_t mode)
     /* DO NOT read BootMap pointer (only one, xECKD) at block #2 */
 
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
-    read_block(0, sec, "Cannot read block 0 to grab boot info.");
+    if (virtio_read(0, sec)) {
+        puts("Cannot read block 0 to grab boot info.");
+        return -EIO;
+    }
     if (mode == ECKD_LDL_UNLABELED) {
         if (!magic_match(ipl1->bip.magic, ZIPL_MAGIC)) {
-            return; /* not applicable layout */
+            return 0; /* not applicable layout */
         }
-        sclp_print("unlabeled LDL.\n");
+        puts("unlabeled LDL.");
     }
     verify_boot_info(&ipl1->bip);
 
@@ -429,8 +498,7 @@ static void ipl_eckd_ldl(ECKD_IPL_mode_t mode)
     /* save pointer to Stage1b Data */
     s1b_block_nr = eckd_block_num(&ipl1->stage1.seek[0].chs);
 
-    run_eckd_boot_script(bmt_block_nr, s1b_block_nr);
-    /* no return */
+    return run_eckd_boot_script(bmt_block_nr, s1b_block_nr);
 }
 
 static block_number_t eckd_find_bmt(ExtEckdBlockPtr *ptr)
@@ -440,7 +508,10 @@ static block_number_t eckd_find_bmt(ExtEckdBlockPtr *ptr)
     BootRecord *br;
 
     blockno = gen_eckd_block_num(ptr, 0);
-    read_block(blockno, tmp_sec, "Cannot read boot record");
+    if (virtio_read(blockno, tmp_sec)) {
+        puts("Cannot read boot record");
+        return ERROR_BLOCK_NR;
+    }
     br = (BootRecord *)tmp_sec;
     if (!magic_match(br->magic, ZIPL_MAGIC)) {
         /* If the boot record is invalid, return and try CCW-IPL instead */
@@ -466,10 +537,10 @@ static void print_eckd_msg(void)
             *p-- = ' ';
         }
     }
-    sclp_print(msg);
+    printf("%s", msg);
 }
 
-static void ipl_eckd(void)
+static int ipl_eckd(void)
 {
     IplVolumeLabel *vlbl = (void *)sec;
     LDL_VTOC *vtoc = (void *)sec;
@@ -479,7 +550,10 @@ static void ipl_eckd(void)
 
     /* Block 2 can contain either the CDL VOL1 label or the LDL VTOC */
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
-    read_block(2, vlbl, "Cannot read block 2");
+    if (virtio_read(2, vlbl)) {
+        puts("Cannot read block 2");
+        return -EIO;
+    }
 
     /*
      * First check for a list-directed-format pointer which would
@@ -487,43 +561,60 @@ static void ipl_eckd(void)
      */
     if (eckd_valid_address((ExtEckdBlockPtr *)&vlbl->f.br, 0)) {
         ldipl_bmt = eckd_find_bmt((ExtEckdBlockPtr *)&vlbl->f.br);
-        if (ldipl_bmt) {
-            sclp_print("List-Directed\n");
-            /* LD-IPL does not use the S1B bock, just make it NULL */
-            run_eckd_boot_script(ldipl_bmt, NULL_BLOCK_NR);
-            /* Only return in error, retry as CCW-IPL */
-            sclp_print("Retrying IPL ");
+        switch (ldipl_bmt) {
+        case ERROR_BLOCK_NR:
+            return -EIO;
+        case NULL_BLOCK_NR:
+            break; /* Invalid BMT but the device may still boot with CCW-IPL */
+        default:
+            puts("List-Directed");
+            /*
+             * LD-IPL does not use the S1B bock, just make it NULL_BLOCK_NR.
+             * In some failure cases retry IPL before aborting.
+             */
+            if (run_eckd_boot_script(ldipl_bmt, NULL_BLOCK_NR)) {
+                return -EIO;
+            }
+            /* Non-fatal error, retry as CCW-IPL */
+            printf("Retrying IPL ");
             print_eckd_msg();
         }
         memset(sec, FREE_SPACE_FILLER, sizeof(sec));
-        read_block(2, vtoc, "Cannot read block 2");
+        if (virtio_read(2, vtoc)) {
+            puts("Cannot read block 2");
+            return -EIO;
+        }
     }
 
     /* Not list-directed */
     if (magic_match(vtoc->magic, VOL1_MAGIC)) {
-        ipl_eckd_cdl(); /* may return in error */
+        if (ipl_eckd_cdl()) {
+            return -1;
+        }
     }
 
     if (magic_match(vtoc->magic, CMS1_MAGIC)) {
-        ipl_eckd_ldl(ECKD_CMS); /* no return */
+        return ipl_eckd_ldl(ECKD_CMS);
     }
     if (magic_match(vtoc->magic, LNX1_MAGIC)) {
-        ipl_eckd_ldl(ECKD_LDL); /* no return */
+        return ipl_eckd_ldl(ECKD_LDL);
     }
 
-    ipl_eckd_ldl(ECKD_LDL_UNLABELED); /* it still may return */
+    if (ipl_eckd_ldl(ECKD_LDL_UNLABELED)) {
+        return -1;
+    }
     /*
      * Ok, it is not a LDL by any means.
      * It still might be a CDL with zero record keys for IPL1 and IPL2
      */
-    ipl_eckd_cdl();
+    return ipl_eckd_cdl();
 }
 
 /***********************************************************************
  * IPL a SCSI disk
  */
 
-static void zipl_load_segment(ComponentEntry *entry)
+static int zipl_load_segment(ComponentEntry *entry)
 {
     const int max_entries = (MAX_SECTOR_SIZE / sizeof(ScsiBlockPtr));
     ScsiBlockPtr *bprs = (void *)sec;
@@ -543,7 +634,10 @@ static void zipl_load_segment(ComponentEntry *entry)
     do {
         memset(bprs, FREE_SPACE_FILLER, bprs_size);
         fill_hex_val(blk_no, &blockno, sizeof(blockno));
-        read_block(blockno, bprs, err_msg);
+        if (virtio_read(blockno, bprs)) {
+            puts(err_msg);
+            return -EIO;
+        }
 
         for (i = 0;; i++) {
             uint64_t *cur_desc = (void *)&bprs[i];
@@ -571,23 +665,37 @@ static void zipl_load_segment(ComponentEntry *entry)
             }
             address = virtio_load_direct(cur_desc[0], cur_desc[1], 0,
                                          (void *)address);
-            IPL_assert(address != -1, "zIPL load segment failed");
+            if (!address) {
+                puts("zIPL load segment failed");
+                return -EIO;
+            }
         }
     } while (blockno);
+
+    return 0;
 }
 
 /* Run a zipl program */
-static void zipl_run(ScsiBlockPtr *pte)
+static int zipl_run(ScsiBlockPtr *pte)
 {
     ComponentHeader *header;
     ComponentEntry *entry;
     uint8_t tmp_sec[MAX_SECTOR_SIZE];
 
-    read_block(pte->blockno, tmp_sec, "Cannot read header");
+    if (virtio_read(pte->blockno, tmp_sec)) {
+        puts("Cannot read header");
+        return -EIO;
+    }
     header = (ComponentHeader *)tmp_sec;
 
-    IPL_assert(magic_match(tmp_sec, ZIPL_MAGIC), "No zIPL magic in header");
-    IPL_assert(header->type == ZIPL_COMP_HEADER_IPL, "Bad header type");
+    if (!magic_match(tmp_sec, ZIPL_MAGIC)) {
+        puts("No zIPL magic in header");
+        return -EINVAL;
+    }
+    if (header->type != ZIPL_COMP_HEADER_IPL) {
+        puts("Bad header type");
+        return -EINVAL;
+    }
 
     dputs("start loading images\n");
 
@@ -602,22 +710,30 @@ static void zipl_run(ScsiBlockPtr *pte)
             continue;
         }
 
-        zipl_load_segment(entry);
+        if (zipl_load_segment(entry)) {
+            return -1;
+        }
 
         entry++;
 
-        IPL_assert((uint8_t *)(&entry[1]) <= (tmp_sec + MAX_SECTOR_SIZE),
-                   "Wrong entry value");
+        if ((uint8_t *)(&entry[1]) > (tmp_sec + MAX_SECTOR_SIZE)) {
+            puts("Wrong entry value");
+            return -EINVAL;
+        }
     }
 
-    IPL_assert(entry->component_type == ZIPL_COMP_ENTRY_EXEC, "No EXEC entry");
+    if (entry->component_type != ZIPL_COMP_ENTRY_EXEC) {
+        puts("No EXEC entry");
+        return -EINVAL;
+    }
 
     /* should not return */
     write_reset_psw(entry->compdat.load_psw);
     jump_to_IPL_code(0);
+    return -1;
 }
 
-static void ipl_scsi(void)
+static int ipl_scsi(void)
 {
     ScsiMbr *mbr = (void *)sec;
     int program_table_entries = 0;
@@ -628,22 +744,34 @@ static void ipl_scsi(void)
 
     /* Grab the MBR */
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
-    read_block(0, mbr, "Cannot read block 0");
+    if (virtio_read(0, mbr)) {
+        puts("Cannot read block 0");
+        return -EIO;
+    }
 
     if (!magic_match(mbr->magic, ZIPL_MAGIC)) {
-        return;
+        return 0;
     }
 
-    sclp_print("Using SCSI scheme.\n");
+    puts("Using SCSI scheme.");
     debug_print_int("MBR Version", mbr->version_id);
     IPL_check(mbr->version_id == 1,
               "Unknown MBR layout version, assuming version 1");
     debug_print_int("program table", mbr->pt.blockno);
-    IPL_assert(mbr->pt.blockno, "No Program Table");
+    if (!mbr->pt.blockno) {
+        puts("No Program Table");
+        return -EINVAL;
+    }
 
     /* Parse the program table */
-    read_block(mbr->pt.blockno, sec, "Error reading Program Table");
-    IPL_assert(magic_match(sec, ZIPL_MAGIC), "No zIPL magic in PT");
+    if (virtio_read(mbr->pt.blockno, sec)) {
+        puts("Error reading Program Table");
+        return -EIO;
+    }
+    if (!magic_match(sec, ZIPL_MAGIC)) {
+        puts("No zIPL magic in Program Table");
+        return -EINVAL;
+    }
 
     for (i = 0; i < MAX_BOOT_ENTRIES; i++) {
         if (prog_table->entry[i].scsi.blockno) {
@@ -653,17 +781,22 @@ static void ipl_scsi(void)
     }
 
     debug_print_int("program table entries", program_table_entries);
-    IPL_assert(program_table_entries != 0, "Empty Program Table");
+    if (program_table_entries == 0) {
+        puts("Empty Program Table");
+        return -EINVAL;
+    }
 
     if (menu_is_enabled_enum()) {
         loadparm = menu_get_enum_boot_index(valid_entries);
     }
 
     debug_print_int("loadparm", loadparm);
-    IPL_assert(loadparm < MAX_BOOT_ENTRIES, "loadparm value greater than"
-               " maximum number of boot entries allowed");
+    if (loadparm >= MAX_BOOT_ENTRIES) {
+        puts("loadparm value greater than max number of boot entries allowed");
+        return -EINVAL;
+    }
 
-    zipl_run(&prog_table->entry[loadparm].scsi); /* no return */
+    return zipl_run(&prog_table->entry[loadparm].scsi);
 }
 
 /***********************************************************************
@@ -677,8 +810,10 @@ static bool is_iso_bc_entry_compatible(IsoBcSection *s)
     if (s->unused || !s->sector_count) {
         return false;
     }
-    read_iso_sector(bswap32(s->load_rba), magic_sec,
-                    "Failed to read image sector 0");
+    if (virtio_read(bswap32(s->load_rba), magic_sec)) {
+        puts("Failed to read image sector 0");
+        return false;
+    }
 
     /* Checking bytes 8 - 32 for S390 Linux magic */
     return !memcmp(magic_sec + 8, linux_s390_magic, 24);
@@ -691,28 +826,35 @@ static uint32_t sec_offset[ISO9660_MAX_DIR_DEPTH];
 /* Remained directory space in bytes */
 static uint32_t dir_rem[ISO9660_MAX_DIR_DEPTH];
 
-static inline uint32_t iso_get_file_size(uint32_t load_rba)
+static inline long iso_get_file_size(uint32_t load_rba)
 {
     IsoVolDesc *vd = (IsoVolDesc *)sec;
     IsoDirHdr *cur_record = &vd->vd.primary.rootdir;
     uint8_t *temp = sec + ISO_SECTOR_SIZE;
     int level = 0;
 
-    read_iso_sector(ISO_PRIMARY_VD_SECTOR, sec,
-                    "Failed to read ISO primary descriptor");
+    if (virtio_read(ISO_PRIMARY_VD_SECTOR, sec)) {
+        puts("Failed to read ISO primary descriptor");
+        return -EIO;
+    }
+
     sec_loc[0] = iso_733_to_u32(cur_record->ext_loc);
     dir_rem[0] = 0;
     sec_offset[0] = 0;
 
     while (level >= 0) {
-        IPL_assert(sec_offset[level] <= ISO_SECTOR_SIZE,
-                   "Directory tree structure violation");
+        if (sec_offset[level] > ISO_SECTOR_SIZE) {
+            puts("Directory tree structure violation");
+            return -EIO;
+        }
 
         cur_record = (IsoDirHdr *)(temp + sec_offset[level]);
 
         if (sec_offset[level] == 0) {
-            read_iso_sector(sec_loc[level], temp,
-                            "Failed to read ISO directory");
+            if (virtio_read(sec_loc[level], temp)) {
+                puts("Failed to read ISO directory");
+                return -EIO;
+            }
             if (dir_rem[level] == 0) {
                 /* Skip self and parent records */
                 dir_rem[level] = iso_733_to_u32(cur_record->data_len) -
@@ -743,7 +885,7 @@ static inline uint32_t iso_get_file_size(uint32_t load_rba)
             if (cur_record->file_flags & 0x2) {
                 /* Subdirectory */
                 if (level == ISO9660_MAX_DIR_DEPTH - 1) {
-                    sclp_print("ISO-9660 directory depth limit exceeded\n");
+                    puts("ISO-9660 directory depth limit exceeded");
                 } else {
                     level++;
                     sec_loc[level] = iso_733_to_u32(cur_record->ext_loc);
@@ -757,8 +899,10 @@ static inline uint32_t iso_get_file_size(uint32_t load_rba)
         if (dir_rem[level] == 0) {
             /* Nothing remaining */
             level--;
-            read_iso_sector(sec_loc[level], temp,
-                            "Failed to read ISO directory");
+            if (virtio_read(sec_loc[level], temp)) {
+                puts("Failed to read ISO directory");
+                return -EIO;
+            }
         }
     }
 
@@ -773,19 +917,24 @@ static void load_iso_bc_entry(IsoBcSection *load)
      * is padded and ISO_SECTOR_SIZE bytes aligned
      */
     uint32_t blks_to_load = bswap16(s.sector_count) >> ET_SECTOR_SHIFT;
-    uint32_t real_size = iso_get_file_size(bswap32(s.load_rba));
+    long real_size = iso_get_file_size(bswap32(s.load_rba));
 
-    if (real_size) {
+    if (real_size > 0) {
         /* Round up blocks to load */
         blks_to_load = (real_size + ISO_SECTOR_SIZE - 1) / ISO_SECTOR_SIZE;
-        sclp_print("ISO boot image size verified\n");
+        puts("ISO boot image size verified");
     } else {
-        sclp_print("ISO boot image size could not be verified\n");
+        puts("ISO boot image size could not be verified");
+        if (real_size < 0) {
+            return;
+        }
     }
 
-    read_iso_boot_image(bswap32(s.load_rba),
+    if (read_iso_boot_image(bswap32(s.load_rba),
                         (void *)((uint64_t)bswap16(s.load_segment)),
-                        blks_to_load);
+                        blks_to_load)) {
+        return;
+    }
 
     jump_to_low_kernel();
 }
@@ -808,17 +957,18 @@ static uint32_t find_iso_bc(void)
                 return bswap32(et->bc_offset);
             }
         }
-        read_iso_sector(block_num++, sec,
-                        "Failed to read ISO volume descriptor");
+        if (virtio_read(block_num++, sec)) {
+            puts("Failed to read ISO volume descriptor");
+            return 0;
+        }
     }
 
     return 0;
 }
 
-static IsoBcSection *find_iso_bc_entry(void)
+static IsoBcSection *find_iso_bc_entry(uint32_t offset)
 {
     IsoBcEntry *e = (IsoBcEntry *)sec;
-    uint32_t offset = find_iso_bc();
     int i;
     unsigned int loadparm = get_loadparm_index();
 
@@ -826,11 +976,13 @@ static IsoBcSection *find_iso_bc_entry(void)
         return NULL;
     }
 
-    read_iso_sector(offset, sec, "Failed to read El Torito boot catalog");
+    if (virtio_read(offset, sec)) {
+        puts("Failed to read El Torito boot catalog");
+        return NULL;
+    }
 
     if (!is_iso_bc_valid(e)) {
         /* The validation entry is mandatory */
-        panic("No valid boot catalog found!\n");
         return NULL;
     }
 
@@ -850,19 +1002,25 @@ static IsoBcSection *find_iso_bc_entry(void)
         }
     }
 
-    panic("No suitable boot entry found on ISO-9660 media!\n");
-
     return NULL;
 }
 
-static void ipl_iso_el_torito(void)
+static int ipl_iso_el_torito(void)
 {
-    IsoBcSection *s = find_iso_bc_entry();
+    uint32_t offset = find_iso_bc();
+    if (!offset) {
+        return 0;
+    }
+
+    IsoBcSection *s = find_iso_bc_entry(offset);
 
     if (s) {
-        load_iso_bc_entry(s);
-        /* no return */
+        load_iso_bc_entry(s); /* only return in error */
+        return -1;
     }
+
+    puts("No suitable boot entry found on ISO-9660 media!");
+    return -EIO;
 }
 
 /**
@@ -884,7 +1042,7 @@ static bool has_iso_signature(void)
  * Bus specific IPL sequences
  */
 
-static void zipl_load_vblk(void)
+static int zipl_load_vblk(void)
 {
     int blksize = virtio_get_block_size();
 
@@ -892,26 +1050,30 @@ static void zipl_load_vblk(void)
         if (blksize != VIRTIO_ISO_BLOCK_SIZE) {
             virtio_assume_iso9660();
         }
-        ipl_iso_el_torito();
+        if (ipl_iso_el_torito()) {
+            return 0;
+        }
     }
 
     if (blksize != VIRTIO_DASD_DEFAULT_BLOCK_SIZE) {
-        sclp_print("Using guessed DASD geometry.\n");
+        puts("Using guessed DASD geometry.");
         virtio_assume_eckd();
     }
-    ipl_eckd();
+    return ipl_eckd();
 }
 
-static void zipl_load_vscsi(void)
+static int zipl_load_vscsi(void)
 {
     if (virtio_get_block_size() == VIRTIO_ISO_BLOCK_SIZE) {
         /* Is it an ISO image in non-CD drive? */
-        ipl_iso_el_torito();
+        if (ipl_iso_el_torito()) {
+            return 0;
+        }
     }
 
-    sclp_print("Using guessed DASD geometry.\n");
+    puts("Using guessed DASD geometry.");
     virtio_assume_eckd();
-    ipl_eckd();
+    return ipl_eckd();
 }
 
 /***********************************************************************
@@ -924,14 +1086,20 @@ void zipl_load(void)
 
     if (vdev->is_cdrom) {
         ipl_iso_el_torito();
-        panic("\n! Cannot IPL this ISO image !\n");
+        puts("Failed to IPL this ISO image!");
+        return;
     }
 
     if (virtio_get_device_type() == VIRTIO_ID_NET) {
-        jump_to_IPL_code(vdev->netboot_start_addr);
+        netmain();
+        puts("Failed to IPL from this network!");
+        return;
     }
 
-    ipl_scsi();
+    if (ipl_scsi()) {
+        puts("Failed to IPL from this SCSI device!");
+        return;
+    }
 
     switch (virtio_get_device_type()) {
     case VIRTIO_ID_BLOCK:
@@ -941,8 +1109,9 @@ void zipl_load(void)
         zipl_load_vscsi();
         break;
     default:
-        panic("\n! Unknown IPL device type !\n");
+        puts("Unknown IPL device type!");
+        return;
     }
 
-    sclp_print("zIPL load failed.\n");
+    puts("zIPL load failed!");
 }