diff options
Diffstat (limited to 'sys/boot/userboot/userboot/elf32_freebsd.c')
| -rw-r--r-- | sys/boot/userboot/userboot/elf32_freebsd.c | 36 |
1 files changed, 25 insertions, 11 deletions
diff --git a/sys/boot/userboot/userboot/elf32_freebsd.c b/sys/boot/userboot/userboot/elf32_freebsd.c index bb5b693..d8ccc33 100644 --- a/sys/boot/userboot/userboot/elf32_freebsd.c +++ b/sys/boot/userboot/userboot/elf32_freebsd.c @@ -45,6 +45,9 @@ static int elf32_obj_exec(struct preloaded_file *amp); struct file_format i386_elf = { elf32_loadfile, elf32_exec }; struct file_format i386_elf_obj = { elf32_obj_loadfile, elf32_obj_exec }; +#define GUEST_STACK 0x1000 /* Initial stack base */ +#define GUEST_GDT 0x3000 /* Address of initial GDT */ + /* * There is an ELF kernel and one or more ELF modules loaded. * We wish to start executing the kernel image, so make such @@ -57,7 +60,7 @@ elf32_exec(struct preloaded_file *fp) Elf_Ehdr *ehdr; vm_offset_t entry, bootinfop, modulep, kernend; int boothowto, err, bootdev; - uint32_t stack[1024]; + uint32_t stack[1024], *sp; if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL) @@ -78,16 +81,27 @@ elf32_exec(struct preloaded_file *fp) /* * Build a scratch stack at physical 0x1000 */ - stack[0] = boothowto; - stack[1] = bootdev; - stack[2] = 0; - stack[3] = 0; - stack[4] = 0; - stack[5] = bootinfop; - stack[6] = modulep; - stack[7] = kernend; - CALLBACK(copyin, stack, 0x1000, sizeof(stack)); - CALLBACK(setreg, 4, 0x1000); + memset(stack, 0, sizeof(stack)); + sp = (uint32_t *)((char *)stack + sizeof(stack)); + *--sp = kernend; + *--sp = modulep; + *--sp = bootinfop; + *--sp = 0; + *--sp = 0; + *--sp = 0; + *--sp = bootdev; + *--sp = boothowto; + + /* + * Fake return address to mimic "new" boot blocks. For more + * details see recover_bootinfo in locore.S. + */ + *--sp = 0xbeefface; + CALLBACK(copyin, stack, GUEST_STACK, sizeof(stack)); + CALLBACK(setreg, 4, (char *)sp - (char *)stack + GUEST_STACK); + + CALLBACK(setgdt, GUEST_GDT, 8 * 4 - 1); + CALLBACK(exec, entry); panic("exec returned"); |
