On s390, there is an architected boot map format that we can read to
boot a certain entry off the disk. Implement a simple reader for this
that always boots the first (default) entry.
Signed-off-by: Alexander Graf <ag...@suse.de>
---
pc-bios/s390-ccw/bootmap.c | 235 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 235 insertions(+), 0 deletions(-)
create mode 100644 pc-bios/s390-ccw/bootmap.c
diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
new file mode 100644
index 0000000..53a460d
--- /dev/null
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -0,0 +1,235 @@
+/*
+ * QEMU S390 bootmap interpreter
+ *
+ * Copyright (c) 2009 Alexander Graf <ag...@suse.de>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include "s390-ccw.h"
+
+// #define DEBUG_FALLBACK
+
+#ifdef DEBUG_FALLBACK
+#define dputs(txt) \
+ do { sclp_print("zipl: " txt); } while (0)
+#else
+#define dputs(fmt, ...) \
+ do { } while (0)
+#endif
+
+struct scsi_blockptr {
+ uint64_t blockno;
+ uint16_t size;
+ uint16_t blockct;
+ uint8_t reserved[4];
+} __attribute__ ((packed));
+
+struct component_entry {
+ struct scsi_blockptr data;
+ uint8_t pad[7];
+ uint8_t component_type;
+ uint64_t load_address;
+} __attribute((packed));
+
+struct component_header {
+ uint8_t magic[4];
+ uint8_t type;
+ uint8_t reserved[27];
+} __attribute((packed));
+
+struct mbr {
+ uint8_t magic[4];
+ uint32_t version_id;
+ uint8_t reserved[8];
+ struct scsi_blockptr blockptr;
+} __attribute__ ((packed));
+
+#define ZIPL_MAGIC "zIPL"
+
+#define ZIPL_COMP_HEADER_IPL 0x00
+#define ZIPL_COMP_HEADER_DUMP 0x01
+
+#define ZIPL_COMP_ENTRY_LOAD 0x02
+#define ZIPL_COMP_ENTRY_EXEC 0x01
+
+/* Scratch space */
+static uint8_t sec[SECTOR_SIZE] __attribute__((__aligned__(SECTOR_SIZE)));
+
+/* Check for ZIPL magic. Returns 0 if not matched. */
+static int zipl_magic(uint8_t *ptr)
+{
+ uint32_t *p = (void*)ptr;
+ uint32_t *z = (void*)ZIPL_MAGIC;
+
+ if (*p != *z) {
+ debug_print_int("invalid magic", *p);
+ virtio_panic("invalid magic");
+ }
+
+ return 1;
+}
+
+static int zipl_load_segment(struct component_entry *entry)
+{
+ const int max_entries = (SECTOR_SIZE / sizeof(struct scsi_blockptr));
+ struct scsi_blockptr *bprs = (void*)sec;
+ uint64_t blockno;
+ long address;
+ int i;
+
+ blockno = entry->data.blockno;
+ address = entry->load_address;
+
+ debug_print_int("loading segment at block", blockno);
+ debug_print_int("addr", address);
+
+ do {
+ if (virtio_read(blockno, (uint8_t *)bprs)) {
+ debug_print_int("failed reading bprs at", blockno);
+ goto fail;
+ }
+
+ for (i = 0;; i++) {
+ u64 *cur_desc = (void*)&bprs[i];
+
+ blockno = bprs[i].blockno;
+ if (!blockno)
+ break;
+
+ /* we need the updated blockno for the next indirect entry in the
+ chain, but don't want to advance address */
+ if (i == (max_entries - 1))
+ break;
+
+ address = virtio_load_direct(cur_desc[0], cur_desc[1], 0,
+ (void*)address);
+ if (address == -1)
+ goto fail;
+ }
+ } while (blockno);
+
+ return 0;
+
+fail:
+ sclp_print("failed loading segment\n");
+ return -1;
+}
+
+/* Run a zipl program */
+static int zipl_run(struct scsi_blockptr *pte)
+{
+ struct component_header *header;
+ struct component_entry *entry;
+ void (*ipl)(void);
+ uint8_t tmp_sec[SECTOR_SIZE];
+
+ virtio_read(pte->blockno, tmp_sec);
+ header = (struct component_header *)tmp_sec;
+
+ if (!zipl_magic(tmp_sec)) {
+ goto fail;
+ }
+
+ if (header->type != ZIPL_COMP_HEADER_IPL) {
+ goto fail;
+ }
+
+ dputs("start loading images\n");
+
+ /* Load image(s) into RAM */
+ entry = (struct component_entry *)(&header[1]);
+ while (entry->component_type == ZIPL_COMP_ENTRY_LOAD) {
+ if (zipl_load_segment(entry) < 0) {
+ goto fail;
+ }
+
+ entry++;
+
+ if ((uint8_t*)(&entry[1]) > (tmp_sec + SECTOR_SIZE)) {
+ goto fail;
+ }
+ }
+
+ if (entry->component_type != ZIPL_COMP_ENTRY_EXEC) {
+ goto fail;
+ }
+
+ /* Ensure the guest output starts fresh */
+ sclp_print("\n");
+
+ /* And run the OS! */
+ ipl = (void*)(entry->load_address & 0x7fffffff);
+ debug_print_addr("set IPL addr to", ipl);
+ /* should not return */
+ ipl();
+
+ return 0;
+
+fail:
+ sclp_print("failed running zipl\n");
+ return -1;
+}
+
+int zipl_load(void)
+{
+ struct mbr *mbr = (void*)sec;
+ uint8_t *ns, *ns_end;
+ int program_table_entries = 0;
+ int pte_len = sizeof(struct scsi_blockptr);
+ struct scsi_blockptr *prog_table_entry;
+ const char *error = "";
+
+ /* Grab the MBR */
+ virtio_read(0, (void*)mbr);
+
+ dputs("checking magic\n");
+
+ if (!zipl_magic(mbr->magic)) {
+ error = "zipl_magic 1";
+ goto fail;
+ }
+
+ debug_print_int("program table", mbr->blockptr.blockno);
+
+ /* Parse the program table */
+ if (virtio_read(mbr->blockptr.blockno, sec)) {
+ error = "virtio_read";
+ goto fail;
+ }
+
+ if (!zipl_magic(sec)) {
+ error = "zipl_magic 2";
+ goto fail;
+ }
+
+ ns_end = sec + SECTOR_SIZE;
+ for (ns = (sec + pte_len); (ns + pte_len) < ns_end; ns++) {
+ prog_table_entry = (struct scsi_blockptr *)ns;
+ if (!prog_table_entry->blockno) {
+ break;
+ }
+
+ program_table_entries++;
+ }
+
+ debug_print_int("program table entries", program_table_entries);
+
+ if (!program_table_entries) {
+ goto fail;
+ }
+
+ /* Run the default entry */
+
+ prog_table_entry = (struct scsi_blockptr *)(sec + pte_len);
+
+ return zipl_run(prog_table_entry);
+
+fail:
+ sclp_print("failed loading zipl: ");
+ sclp_print(error);
+ sclp_print("\n");
+ return -1;
+}
--
1.6.0.2
