| /*␊ |
| File added by David F. Elliott <dfe@cox.net> on 2007/06/26␊ |
| */␊ |
| ␊ |
| #include "libsaio.h"␊ |
| #include "boot.h"␊ |
| ␊ |
| #include "mboot.h"␊ |
| ␊ |
| int multiboot_timeout=0;␊ |
| int multiboot_timeout_set=0;␊ |
| int multiboot_partition=0;␊ |
| int multiboot_partition_set=0;␊ |
| ␊ |
| // Global multiboot info, if using multiboot.␊ |
| struct multiboot_info *gMI;␊ |
| ␊ |
| extern void continue_at_low_address(void);␊ |
| ␊ |
| // prototype hi_multiboot and keep its implementation below multiboot_to_boot␊ |
| // to ensure that it doesn't get inlined by the compiler␊ |
| // We don't want it inlined because we specifically want the stack frame␊ |
| // pointer to be as high as possible and the hi_multiboot function␊ |
| // copies multiboot_info onto its stack.␊ |
| uint32_t hi_multiboot(int multiboot_magic, struct multiboot_info *mi_orig);␊ |
| // prototype dochainload for the same reason.␊ |
| void dochainload();␊ |
| ␊ |
| #define OFFSET_1MEG 0x100000␊ |
| #define BAD_BOOT_DEVICE 0xffffffff␊ |
| ␊ |
| // This assumes that the address of the first argument to the function will␊ |
| // be exactly 4 bytes above the address of the return address.␊ |
| // It is intended to be used as an lvalue with a statement like this -= OFFSET_1MEG;␊ |
| #define RETURN_ADDRESS_USING_FIRST_ARG(arg) \␊ |
| (*(uint32_t*)((char*)&(arg) - 4))␊ |
| ␊ |
| #define FIX_RETURN_ADDRESS_USING_FIRST_ARG(arg) \␊ |
| RETURN_ADDRESS_USING_FIRST_ARG(arg) -= OFFSET_1MEG␊ |
| ␊ |
| extern void jump_to_chainbooter();␊ |
| extern unsigned char chainbootdev;␊ |
| extern unsigned char chainbootflag;␊ |
| ␊ |
| void chainLoad();␊ |
| void waitThenReload();␊ |
| ␊ |
| /*␊ |
| int multibootRamdiskReadBytes( int biosdev, unsigned int blkno,␊ |
| unsigned int byteoff,␊ |
| unsigned int byteCount, void * buffer );␊ |
| int multiboot_get_ramdisk_info(int biosdev, struct driveInfo *dip);␊ |
| static long multiboot_LoadExtraDrivers(FileLoadDrivers_t FileLoadDrivers_p);␊ |
| */␊ |
| ␊ |
| // Starts off in the multiboot context 1 MB high but eventually gets into low memory␊ |
| // and winds up with a bootdevice in eax which is all that boot() wants␊ |
| // This lets the stack pointer remain very high.␊ |
| // If we were to call boot directly from multiboot then the whole multiboot_info␊ |
| // would be on the stack which would possibly be using way too much stack.␊ |
| void multiboot_to_boot(int multiboot_magic, struct multiboot_info *mi_orig)␊ |
| {␊ |
| uint32_t bootdevice = hi_multiboot(multiboot_magic, mi_orig);␊ |
| if(bootdevice != BAD_BOOT_DEVICE)␊ |
| {␊ |
| // boot only returns to do a chain load.␊ |
| for(;;)␊ |
| { // NOTE: boot only uses the last byte (the drive number)␊ |
| common_boot(bootdevice);␊ |
| if(chainbootflag)␊ |
| chainLoad();␊ |
| else␊ |
| waitThenReload();␊ |
| }␊ |
| }␊ |
| // Avoid returning to high-memory address which isn't valid in the segment␊ |
| // we are now in.␊ |
| // Calling sleep() ensures the user ought to be able to use Ctrl+Alt+Del␊ |
| // because the BIOS will have interrupts on.␊ |
| for(;;)␊ |
| sleep(10);␊ |
| // NOTE: *IF* we needed to return we'd have to fix up our return address to␊ |
| // be in low memory using the same trick as below.␊ |
| // However, there doesn't seem to be any point in returning to assembly␊ |
| // particularly when the remaining code merely halts the processor.␊ |
| }␊ |
| ␊ |
| void chainLoad()␊ |
| {␊ |
| /* TODO: We ought to load the appropriate partition table, for example␊ |
| the MBR if booting a primary partition or the particular extended␊ |
| partition table if booting a logical drive. For example, the␊ |
| regular MS MBR booter will relocate itself (e.g. the MBR) from␊ |
| 0:7C00 to 0:0600 and will use SI as the offset when reading␊ |
| the partition data from itself. Thus when it jumps to the partition␊ |
| boot sector, SI will be 0x600 + 446 + i<<4 where i is the partition␊ |
| table index.␊ |
| ␊ |
| On the other hand, our code for the non-Multiboot case doesn't do␊ |
| this either, although GRUB does.␊ |
| */␊ |
| ␊ |
| const unsigned char *bootcode = (const unsigned char*)0x7c00;␊ |
| if(bootcode[0x1fe] == 0x55 && bootcode[0x1ff] == 0xaa)␊ |
| {␊ |
| printf("Calling chainbooter\n");␊ |
| jump_to_chainbooter();␊ |
| /* NORETURN */␊ |
| }␊ |
| else␊ |
| {␊ |
| printf("Bad chain boot sector magic: %02x%02x\n", bootcode[0x1fe], bootcode[0x1ff]);␊ |
| }␊ |
| }␊ |
| ␊ |
| void waitThenReload()␊ |
| {␊ |
| /* FIXME: Ctrl+Alt+Del does not work under Boot Camp */␊ |
| printf("Darwin booter exited for some reason.\n");␊ |
| printf("Please reboot (Ctrl+Alt+Del) your machine.\n");␊ |
| printf("Restarting Darwin booter in 5 seconds...");␊ |
| sleep(1);␊ |
| printf("4...");␊ |
| sleep(1);␊ |
| printf("3...");␊ |
| sleep(1);␊ |
| printf("2...");␊ |
| sleep(1);␊ |
| printf("1...");␊ |
| sleep(1);␊ |
| printf("0\n");␊ |
| }␊ |
| ␊ |
| // Declare boot2_sym as an opaque struct so it can't be converted to a pointer␊ |
| // i.e. ensure the idiot programmer (me) makes sure to use address-of␊ |
| // Technically it's a function but it's real mode code and we sure don't␊ |
| // want to call it under any circumstances.␊ |
| extern struct {} boot2_sym asm("boot2");␊ |
| ␊ |
| // prototype multiboot and keep its implementation below hi_multiboot to␊ |
| // ensure that it doesn't get inlined by the compiler␊ |
| static inline uint32_t multiboot(int multiboot_magic, struct multiboot_info *mi);␊ |
| ␊ |
| ␊ |
| /*!␊ |
| Returns a pointer to the first safe address we can use for stowing the multiboot info.␊ |
| This might actually be a bit pedantic because mboot.c32 and GRUB both stow the multiboot␊ |
| info in low memory meaning that the >= 128 MB location we choose is plenty high enough.␊ |
| */␊ |
| void *determine_safe_hi_addr(int multiboot_magic, struct multiboot_info *mi_orig)␊ |
| {␊ |
| // hi_addr must be at least up in 128MB+ space so it doesn't get clobbered␊ |
| void *hi_addr = (void*)PREBOOT_DATA;␊ |
| ␊ |
| // Fail if the magic isn't correct. We'll complain later.␊ |
| if(multiboot_magic != MULTIBOOT_INFO_MAGIC)␊ |
| return NULL;␊ |
| // Make sure the command-line isn't in high memory.␊ |
| if(mi_orig->mi_flags & MULTIBOOT_INFO_HAS_CMDLINE)␊ |
| {␊ |
| char *end = mi_orig->mi_cmdline;␊ |
| if(end != NULL)␊ |
| {␊ |
| for(; *end != '\0'; ++end)␊ |
| ;␊ |
| ++end;␊ |
| if( (void*)end > hi_addr)␊ |
| hi_addr = end;␊ |
| }␊ |
| }␊ |
| // Make sure the module information isn't in high memory␊ |
| if(mi_orig->mi_flags & MULTIBOOT_INFO_HAS_MODS)␊ |
| {␊ |
| struct multiboot_module *modules = (void*)mi_orig->mi_mods_addr;␊ |
| int i;␊ |
| for(i=0; i < mi_orig->mi_mods_count; ++i)␊ |
| {␊ |
| // make sure the multiboot_module struct itself won't get clobbered␊ |
| void *modinfo_end = modules+i+1;␊ |
| if(modinfo_end > hi_addr)␊ |
| hi_addr = modinfo_end;␊ |
| // make sure the module itself won't get clobbered␊ |
| modinfo_end = (void*)modules[i].mm_mod_end;␊ |
| if(modinfo_end > hi_addr)␊ |
| hi_addr = modinfo_end;␊ |
| // make sure the module string doesn't get clobbered␊ |
| char *end = modules[i].mm_string;␊ |
| for(; *end != '\0'; ++end)␊ |
| ;␊ |
| ++end;␊ |
| modinfo_end = end;␊ |
| if(modinfo_end > hi_addr)␊ |
| hi_addr = modinfo_end;␊ |
| }␊ |
| }␊ |
| // TODO: Copy syms (never needed), mmap, drives, config table, loader name, apm table, VBE info␊ |
| ␊ |
| // Round up to page size␊ |
| hi_addr = (void*)(((uint32_t)hi_addr + 0xfff) & ~(uint32_t)0xfff);␊ |
| return hi_addr;␊ |
| }␊ |
| ␊ |
| /*!␊ |
| Like malloc but with a preceding input/output parameter which points to the next available␊ |
| location for data. The original value of *hi_addr is returned and *hi_addr is incremented␊ |
| by size bytes.␊ |
| */␊ |
| void * _hi_malloc(void **hi_addr, size_t size)␊ |
| {␊ |
| void *ret = *hi_addr;␊ |
| *hi_addr += size;␊ |
| return ret;␊ |
| }␊ |
| ␊ |
| /*!␊ |
| Like strdup but with a preceding input/output parameter. The original value of *hi_addr is␊ |
| returned and *hi_addr is incremented by the number of bytes necessary to complete the string␊ |
| copy including its NUL terminator.␊ |
| */␊ |
| char * _hi_strdup(void **hi_addr, char *src)␊ |
| {␊ |
| char *dstStart;␊ |
| char *dst = dstStart = *hi_addr;␊ |
| for(; *src != '\0'; ++src, ++dst, ++(*hi_addr))␊ |
| *dst = *src;␊ |
| *dst = '\0';␊ |
| ++(*hi_addr);␊ |
| return dstStart;␊ |
| }␊ |
| ␊ |
| // Convenience macros␊ |
| #define hi_malloc(size) _hi_malloc(&hi_addr, (size))␊ |
| #define hi_strdup(src) _hi_strdup(&hi_addr, (src))␊ |
| ␊ |
| /*!␊ |
| Copies the Multiboot info and any associated data (e.g. various strings and any multiboot modules)␊ |
| up to very high RAM (above 128 MB) to ensure it doesn't get clobbered by the booter.␊ |
| */␊ |
| struct multiboot_info * copyMultibootInfo(int multiboot_magic, struct multiboot_info *mi_orig)␊ |
| {␊ |
| void *hi_addr = determine_safe_hi_addr(multiboot_magic, mi_orig);␊ |
| if(hi_addr == NULL)␊ |
| return NULL;␊ |
| ␊ |
| struct multiboot_info *mi_copy = hi_malloc(sizeof(*mi_copy));␊ |
| memcpy(mi_copy, mi_orig, sizeof(*mi_copy));␊ |
| ␊ |
| // Copy the command line␊ |
| if(mi_orig->mi_flags & MULTIBOOT_INFO_HAS_CMDLINE)␊ |
| {␊ |
| mi_copy->mi_cmdline = hi_strdup(mi_orig->mi_cmdline);␊ |
| }␊ |
| // Copy the loader name␊ |
| if(mi_orig->mi_flags & MULTIBOOT_INFO_HAS_LOADER_NAME)␊ |
| {␊ |
| mi_copy->mi_loader_name = hi_strdup(mi_orig->mi_loader_name);␊ |
| }␊ |
| // Copy the module info␊ |
| if(mi_orig->mi_flags & MULTIBOOT_INFO_HAS_MODS)␊ |
| {␊ |
| struct multiboot_module *dst_modules = hi_malloc(sizeof(*dst_modules)*mi_orig->mi_mods_count);␊ |
| struct multiboot_module *src_modules = (void*)mi_orig->mi_mods_addr;␊ |
| mi_copy->mi_mods_addr = (uint32_t)dst_modules;␊ |
| ␊ |
| // Copy all of the module info plus the actual module into high memory␊ |
| int i;␊ |
| for(i=0; i < mi_orig->mi_mods_count; ++i)␊ |
| {␊ |
| // Assume mod_end is 1 past the actual end (i.e. it is start + size, not really end (i.e. start + size - 1))␊ |
| // This is what GRUB and mboot.c32 do although the spec is unclear on this.␊ |
| uint32_t mod_length = src_modules[i].mm_mod_end - src_modules[i].mm_mod_start;␊ |
| ␊ |
| dst_modules[i].mm_mod_start = (uint32_t)hi_malloc(mod_length);␊ |
| dst_modules[i].mm_mod_end = (uint32_t)dst_modules[i].mm_mod_start + mod_length;␊ |
| memcpy((char*)dst_modules[i].mm_mod_start, (char*)src_modules[i].mm_mod_start, mod_length);␊ |
| ␊ |
| dst_modules[i].mm_string = hi_strdup(src_modules[i].mm_string);␊ |
| dst_modules[i].mm_reserved = src_modules[i].mm_reserved;␊ |
| }␊ |
| }␊ |
| // Make sure that only stuff that didn't need to be copied or that we did deep copy is indicated in the copied struct.␊ |
| mi_copy->mi_flags &= MULTIBOOT_INFO_HAS_MEMORY | MULTIBOOT_INFO_HAS_BOOT_DEVICE | MULTIBOOT_INFO_HAS_CMDLINE | MULTIBOOT_INFO_HAS_LOADER_NAME | MULTIBOOT_INFO_HAS_MODS;␊ |
| ␊ |
| return mi_copy;␊ |
| }␊ |
| ␊ |
| // When we enter, we're actually 1 MB high.␊ |
| // Fortunately, memcpy is position independent, and it's all we need␊ |
| uint32_t hi_multiboot(int multiboot_magic, struct multiboot_info *mi_orig)␊ |
| {␊ |
| // Copy the multiboot info out of the way.␊ |
| // We can't bitch about the magic yet because printf won't work␊ |
| // because it contains an absolute location of putchar which␊ |
| // contains absolute locations to other things which eventually␊ |
| // makes a BIOS call from real mode which of course won't work␊ |
| // because we're stuck in extended memory at this point.␊ |
| struct multiboot_info *mi_p = copyMultibootInfo(multiboot_magic, mi_orig);␊ |
| ␊ |
| // Get us in to low memory so we can run everything␊ |
| ␊ |
| // We cannot possibly be more than 447k and copying extra won't really hurt anything␊ |
| // We use the address of the assembly entrypoint to get our starting location.␊ |
| memcpy(&boot2_sym, (char*)&boot2_sym + OFFSET_1MEG, BOOT2_MAX_LENGTH /* 447k */);␊ |
| ␊ |
| // This is a little assembler routine that returns to us in the correct selector␊ |
| // instead of the kernel selector we're running in now and at the correct␊ |
| // instruction pointer ( current minus 1 MB ). It does not fix our return␊ |
| // address nor does it fix the return address of our caller.␊ |
| continue_at_low_address();␊ |
| ␊ |
| // Now fix our return address.␊ |
| FIX_RETURN_ADDRESS_USING_FIRST_ARG(multiboot_magic);␊ |
| ␊ |
| // We can now do just about anything, including return to our caller correctly.␊ |
| // However, our caller must fix his return address if he wishes to return to␊ |
| // his caller and so on and so forth.␊ |
| ␊ |
| /* Zero the BSS and initialize malloc */␊ |
| initialize_runtime();␊ |
| ␊ |
| gMI = mi_p;␊ |
| ␊ |
| /* Set up a temporary bootArgs so we can call console output routines␊ |
| like printf that check the v_display. Note that we purposefully␊ |
| do not initialize anything else at this early stage.␊ |
| ␊ |
| We are reasonably sure we're already in text mode if GRUB booted us.␊ |
| This is the same assumption that initKernBootStruct makes.␊ |
| We could check the multiboot info I guess, but why bother?␊ |
| */␊ |
| boot_args temporaryBootArgsData;␊ |
| bzero(&temporaryBootArgsData, sizeof(boot_args));␊ |
| // bootArgs = &temporaryBootArgsData;␊ |
| // bootArgs->Video.v_display = VGA_TEXT_MODE;␊ |
| ␊ |
| // Install ramdisk and extra driver hooks␊ |
| //p_get_ramdisk_info = &multiboot_get_ramdisk_info;␊ |
| //p_ramdiskReadBytes = &multibootRamdiskReadBytes;␊ |
| //LoadExtraDrivers_p = &multiboot_LoadExtraDrivers;␊ |
| ␊ |
| // Since we call multiboot ourselves, its return address will be correct.␊ |
| // That is unless it's inlined in which case it does not matter.␊ |
| uint32_t bootdevice = multiboot(multiboot_magic, mi_p);␊ |
| // We're about to exit and temporaryBootArgs will no longer be valid␊ |
| //bootArgs = NULL;␊ |
| return bootdevice;␊ |
| }␊ |
| ␊ |
| // This is the meat of our implementation. It grabs the boot device from␊ |
| // the multiboot_info and returns it as is. If it fails it returns␊ |
| // BAD_BOOT_DEVICE. We can call an awful lot of libsa and libsaio but␊ |
| // we need to take care not to call anything that requires malloc because␊ |
| // it won't be initialized until boot() does it.␊ |
| static inline uint32_t multiboot(int multiboot_magic, struct multiboot_info *mi)␊ |
| {␊ |
| if(multiboot_magic != MULTIBOOT_INFO_MAGIC)␊ |
| {␊ |
| printf("Wrong Multiboot magic\n");␊ |
| sleep(2);␊ |
| return BAD_BOOT_DEVICE;␊ |
| }␊ |
| printf("Multiboot info @0x%x\n", (uint32_t)mi);␊ |
| if(mi->mi_flags & MULTIBOOT_INFO_HAS_LOADER_NAME)␊ |
| printf("Loaded by %s\n", mi->mi_loader_name);␊ |
| ␊ |
| // Multiboot puts boot device in high byte␊ |
| // Normal booter wants it in low byte␊ |
| int bootdevice = mi->mi_boot_device_drive;␊ |
| ␊ |
| bool doSelectDevice = false;␊ |
| if(mi->mi_flags & MULTIBOOT_INFO_HAS_BOOT_DEVICE)␊ |
| {␊ |
| printf("Boot device 0x%x\n", bootdevice);␊ |
| }␊ |
| else␊ |
| {␊ |
| printf("Multiboot info does not include chosen boot device\n");␊ |
| doSelectDevice = true;␊ |
| bootdevice = BAD_BOOT_DEVICE;␊ |
| }␊ |
| ␊ |
| if(bootdevice == BAD_BOOT_DEVICE)␊ |
| sleep(2); // pause for a second before halting␊ |
| return bootdevice;␊ |
| }␊ |
| ␊ |
| ///////////////////////////////////////////////////////////////////////////␊ |
| // Ramdisk and extra drivers code␊ |
| #if 0␊ |
| int multibootRamdiskReadBytes( int biosdev, unsigned int blkno,␊ |
| unsigned int byteoff,␊ |
| unsigned int byteCount, void * buffer )␊ |
| {␊ |
| int module_count = gMI->mi_mods_count;␊ |
| struct multiboot_module *modules = (void*)gMI->mi_mods_addr;␊ |
| if(biosdev < 0x100)␊ |
| return -1;␊ |
| if(biosdev >= (0x100 + module_count))␊ |
| return -1;␊ |
| struct multiboot_module *module = modules + (biosdev - 0x100);␊ |
| ␊ |
| void *p_initrd = (void*)module->mm_mod_start;␊ |
| bcopy(p_initrd + blkno*512 + byteoff, buffer, byteCount);␊ |
| return 0;␊ |
| }␊ |
| ␊ |
| int multiboot_get_ramdisk_info(int biosdev, struct driveInfo *dip)␊ |
| {␊ |
| int module_count = gMI->mi_mods_count;␊ |
| struct multiboot_module *modules = (void*)gMI->mi_mods_addr;␊ |
| if(biosdev < 0x100)␊ |
| return -1;␊ |
| if(biosdev >= (0x100 + module_count))␊ |
| return -1;␊ |
| struct multiboot_module *module = modules + (biosdev - 0x100);␊ |
| dip->biosdev = biosdev;␊ |
| dip->uses_ebios = true;␉// XXX aserebln uses_ebios isn't a boolean at all␊ |
| dip->di.params.phys_sectors = (module->mm_mod_end - module->mm_mod_start + 511) / 512;␊ |
| dip->valid = true;␊ |
| return 0;␊ |
| }␊ |
| static long multiboot_LoadExtraDrivers(FileLoadDrivers_t FileLoadDrivers_p)␊ |
| {␊ |
| char extensionsSpec[1024];␊ |
| int ramdiskUnit;␊ |
| for(ramdiskUnit = 0; ramdiskUnit < gMI->mi_mods_count; ++ramdiskUnit)␊ |
| {␊ |
| int partCount; // unused␊ |
| BVRef ramdiskChain = diskScanBootVolumes(0x100 + ramdiskUnit, &partCount);␊ |
| if(ramdiskChain == NULL)␊ |
| {␊ |
| verbose("Ramdisk contains no partitions\n");␊ |
| continue;␊ |
| }␊ |
| for(; ramdiskChain != NULL; ramdiskChain = ramdiskChain->next)␊ |
| {␊ |
| sprintf(extensionsSpec, "rd(%d,%d)/Extra/", ramdiskUnit, ramdiskChain->part_no);␊ |
| struct dirstuff *extradir = opendir(extensionsSpec);␊ |
| closedir(extradir);␊ |
| if(extradir != NULL)␊ |
| {␊ |
| int ret = FileLoadDrivers_p(extensionsSpec, 0 /* this is a kext root dir, not a kext with plugins */);␊ |
| if(ret != 0)␊ |
| {␊ |
| verbose("FileLoadDrivers failed on a ramdisk\n");␊ |
| return ret;␊ |
| }␊ |
| }␊ |
| }␊ |
| }␊ |
| return 0;␊ |
| }␊ |
| #endif |
