1*9a848adfSThomas Huth /* 2*9a848adfSThomas Huth * QEMU s390-ccw firmware - jump to IPL code 3*9a848adfSThomas Huth * 4*9a848adfSThomas Huth * This work is licensed under the terms of the GNU GPL, version 2 or (at 5*9a848adfSThomas Huth * your option) any later version. See the COPYING file in the top-level 6*9a848adfSThomas Huth * directory. 7*9a848adfSThomas Huth */ 8*9a848adfSThomas Huth 9*9a848adfSThomas Huth #include "libc.h" 10*9a848adfSThomas Huth #include "s390-ccw.h" 11*9a848adfSThomas Huth 12*9a848adfSThomas Huth #define KERN_IMAGE_START 0x010000UL 13*9a848adfSThomas Huth #define PSW_MASK_64 0x0000000100000000ULL 14*9a848adfSThomas Huth #define PSW_MASK_32 0x0000000080000000ULL 15*9a848adfSThomas Huth #define IPL_PSW_MASK (PSW_MASK_32 | PSW_MASK_64) 16*9a848adfSThomas Huth 17*9a848adfSThomas Huth typedef struct ResetInfo { 18*9a848adfSThomas Huth uint32_t ipl_mask; 19*9a848adfSThomas Huth uint32_t ipl_addr; 20*9a848adfSThomas Huth uint32_t ipl_continue; 21*9a848adfSThomas Huth } ResetInfo; 22*9a848adfSThomas Huth 23*9a848adfSThomas Huth static ResetInfo save; 24*9a848adfSThomas Huth 25*9a848adfSThomas Huth static void jump_to_IPL_2(void) 26*9a848adfSThomas Huth { 27*9a848adfSThomas Huth ResetInfo *current = 0; 28*9a848adfSThomas Huth 29*9a848adfSThomas Huth void (*ipl)(void) = (void *) (uint64_t) current->ipl_continue; 30*9a848adfSThomas Huth *current = save; 31*9a848adfSThomas Huth ipl(); /* should not return */ 32*9a848adfSThomas Huth } 33*9a848adfSThomas Huth 34*9a848adfSThomas Huth void jump_to_IPL_code(uint64_t address) 35*9a848adfSThomas Huth { 36*9a848adfSThomas Huth /* store the subsystem information _after_ the bootmap was loaded */ 37*9a848adfSThomas Huth write_subsystem_identification(); 38*9a848adfSThomas Huth 39*9a848adfSThomas Huth /* prevent unknown IPL types in the guest */ 40*9a848adfSThomas Huth if (iplb.pbt == S390_IPL_TYPE_QEMU_SCSI) { 41*9a848adfSThomas Huth iplb.pbt = S390_IPL_TYPE_CCW; 42*9a848adfSThomas Huth set_iplb(&iplb); 43*9a848adfSThomas Huth } 44*9a848adfSThomas Huth 45*9a848adfSThomas Huth /* 46*9a848adfSThomas Huth * The IPL PSW is at address 0. We also must not overwrite the 47*9a848adfSThomas Huth * content of non-BIOS memory after we loaded the guest, so we 48*9a848adfSThomas Huth * save the original content and restore it in jump_to_IPL_2. 49*9a848adfSThomas Huth */ 50*9a848adfSThomas Huth ResetInfo *current = 0; 51*9a848adfSThomas Huth 52*9a848adfSThomas Huth save = *current; 53*9a848adfSThomas Huth current->ipl_addr = (uint32_t) (uint64_t) &jump_to_IPL_2; 54*9a848adfSThomas Huth current->ipl_continue = address & 0x7fffffff; 55*9a848adfSThomas Huth 56*9a848adfSThomas Huth debug_print_int("set IPL addr to", current->ipl_continue); 57*9a848adfSThomas Huth 58*9a848adfSThomas Huth /* Ensure the guest output starts fresh */ 59*9a848adfSThomas Huth sclp_print("\n"); 60*9a848adfSThomas Huth 61*9a848adfSThomas Huth /* 62*9a848adfSThomas Huth * HACK ALERT. 63*9a848adfSThomas Huth * We use the load normal reset to keep r15 unchanged. jump_to_IPL_2 64*9a848adfSThomas Huth * can then use r15 as its stack pointer. 65*9a848adfSThomas Huth */ 66*9a848adfSThomas Huth asm volatile("lghi 1,1\n\t" 67*9a848adfSThomas Huth "diag 1,1,0x308\n\t" 68*9a848adfSThomas Huth : : : "1", "memory"); 69*9a848adfSThomas Huth panic("\n! IPL returns !\n"); 70*9a848adfSThomas Huth } 71*9a848adfSThomas Huth 72*9a848adfSThomas Huth void jump_to_low_kernel(void) 73*9a848adfSThomas Huth { 74*9a848adfSThomas Huth /* 75*9a848adfSThomas Huth * If it looks like a Linux binary, i.e. there is the "S390EP" magic from 76*9a848adfSThomas Huth * arch/s390/kernel/head.S here, then let's jump to the well-known Linux 77*9a848adfSThomas Huth * kernel start address (when jumping to the PSW-at-zero address instead, 78*9a848adfSThomas Huth * the kernel startup code fails when we booted from a network device). 79*9a848adfSThomas Huth */ 80*9a848adfSThomas Huth if (!memcmp((char *)0x10008, "S390EP", 6)) { 81*9a848adfSThomas Huth jump_to_IPL_code(KERN_IMAGE_START); 82*9a848adfSThomas Huth } 83*9a848adfSThomas Huth 84*9a848adfSThomas Huth /* Trying to get PSW at zero address */ 85*9a848adfSThomas Huth if (*((uint64_t *)0) & IPL_PSW_MASK) { 86*9a848adfSThomas Huth jump_to_IPL_code((*((uint64_t *)0)) & 0x7fffffff); 87*9a848adfSThomas Huth } 88*9a848adfSThomas Huth 89*9a848adfSThomas Huth /* No other option left, so use the Linux kernel start address */ 90*9a848adfSThomas Huth jump_to_IPL_code(KERN_IMAGE_START); 91*9a848adfSThomas Huth } 92