/* * This file is part of the coreboot project. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include /* Place the stack in the bss section. It's not necessary to define it in the * the linker script. */ .section .bss, "aw", @nobits .global _stack .global _estack .align CONFIG_STACK_SIZE _stack: .space CONFIG_MAX_CPUS*CONFIG_STACK_SIZE _estack: #if CONFIG_COOP_MULTITASKING .global thread_stacks thread_stacks: .space CONFIG_STACK_SIZE*CONFIG_NUM_THREADS #endif .section ".text._start", "ax", @progbits #ifdef __x86_64__ .code64 #else .code32 #endif .globl _start _start: cli lgdt %cs:gdtaddr #ifndef __x86_64__ ljmp $0x10, $1f #endif 1: movl $0x18, %eax movl %eax, %ds movl %eax, %es movl %eax, %ss movl %eax, %fs movl %eax, %gs #ifdef __x86_64__ mov $0x48, %ecx call SetCodeSelector #endif post_code(POST_ENTRY_C_START) /* post 13 */ cld /** poison the stack. Code should not count on the * stack being full of zeros. This stack poisoning * recently uncovered a bug in the broadcast SIPI * code. */ leal _stack, %edi movl $_estack, %ecx subl %edi, %ecx shrl $2, %ecx /* it is 32 bit aligned, right? */ movl $0xDEADBEEF, %eax rep stosl /* set new stack */ movl $_estack, %esp #if CONFIG_COOP_MULTITASKING /* Push the thread pointer. */ push $0 #endif /* Push the cpu index and struct cpu */ push $0 push $0 /* Initialize the Interrupt Descriptor table */ leal _idt, %edi leal vec0, %ebx movl $(0x10 << 16), %eax /* cs selector */ 1: movw %bx, %ax movl %ebx, %edx movw $0x8E00, %dx /* Interrupt gate - dpl=0, present */ movl %eax, 0(%edi) movl %edx, 4(%edi) addl $6, %ebx addl $8, %edi cmpl $_idt_end, %edi jne 1b /* Load the Interrupt descriptor table */ #ifndef __x86_64__ lidt idtarg #else // FIXME port table to x64 - lidt idtarg #endif /* * Now we are finished. Memory is up, data is copied and * bss is cleared. Now we call the main routine and * let it do the rest. */ post_code(POST_PRE_HARDWAREMAIN) /* post fe */ #if CONFIG_GDB_WAIT call gdb_hw_init call gdb_stub_breakpoint #endif call main /* NOTREACHED */ .Lhlt: post_code(POST_DEAD_CODE) /* post ee */ hlt jmp .Lhlt vec0: push $0 /* error code */ push $0 /* vector */ jmp int_hand vec1: push $0 /* error code */ push $1 /* vector */ jmp int_hand vec2: push $0 /* error code */ push $2 /* vector */ jmp int_hand vec3: push $0 /* error code */ push $3 /* vector */ jmp int_hand vec4: push $0 /* error code */ push $4 /* vector */ jmp int_hand vec5: push $0 /* error code */ push $5 /* vector */ jmp int_hand vec6: push $0 /* error code */ push $6 /* vector */ jmp int_hand vec7: push $0 /* error code */ push $7 /* vector */ jmp int_hand vec8: /* error code */ push $8 /* vector */ jmp int_hand .word 0x9090 vec9: push $0 /* error code */ push $9 /* vector */ jmp int_hand vec10: /* error code */ push $10 /* vector */ jmp int_hand .word 0x9090 vec11: /* error code */ push $11 /* vector */ jmp int_hand .word 0x9090 vec12: /* error code */ push $12 /* vector */ jmp int_hand .word 0x9090 vec13: /* error code */ push $13 /* vector */ jmp int_hand .word 0x9090 vec14: /* error code */ push $14 /* vector */ jmp int_hand .word 0x9090 vec15: push $0 /* error code */ push $15 /* vector */ jmp int_hand vec16: push $0 /* error code */ push $16 /* vector */ jmp int_hand vec17: /* error code */ push $17 /* vector */ jmp int_hand .word 0x9090 vec18: push $0 /* error code */ push $18 /* vector */ jmp int_hand vec19: push $0 /* error code */ push $19 /* vector */ jmp int_hand int_hand: /* At this point, on x86-32, on the stack there is: * 0(%esp) vector * 4(%esp) error code * 8(%esp) eip * 12(%esp) cs * 16(%esp) eflags */ #ifdef __x86_64__ push %rdi push %rsi push %rbp /* Original stack pointer */ lea 32(%rsp), %rbp push %rbp push %rbx push %rdx push %rcx push %rax push %rsp /* Pointer to structure on the stack */ call x86_exception pop %rax /* Drop the pointer */ pop %rax pop %rcx pop %rdx pop %rbx pop %rbp /* Ignore saved %rsp value */ pop %rbp pop %rsi pop %rdi add $8, %rsp /* pop of the vector and error code */ #else pushl %edi pushl %esi pushl %ebp /* Original stack pointer */ leal 32(%esp), %ebp pushl %ebp pushl %ebx pushl %edx pushl %ecx pushl %eax pushl %esp /* Pointer to structure on the stack */ call x86_exception pop %eax /* Drop the pointer */ popl %eax popl %ecx popl %edx popl %ebx popl %ebp /* Ignore saved %esp value */ popl %ebp popl %esi popl %edi addl $8, %esp /* pop of the vector and error code */ #endif iret #if CONFIG_GDB_WAIT .globl gdb_stub_breakpoint gdb_stub_breakpoint: #ifdef __x86_64__ pop %rax /* Return address */ pushfl push %cs push %rax /* Return address */ push $0 /* No error code */ push $32 /* vector 32 is user defined */ #else popl %eax /* Return address */ pushfl pushl %cs pushl %eax /* Return address */ pushl $0 /* No error code */ pushl $32 /* vector 32 is user defined */ #endif jmp int_hand #endif .globl gdt, gdt_end, idtarg gdtaddr: .word gdt_end - gdt - 1 #ifdef __x86_64__ .quad gdt #else .long gdt /* we know the offset */ #endif .data /* This is the gdt for GCC part of coreboot. * It is different from the gdt in ROMCC/ASM part of coreboot * which is defined in entry32.inc * * When the machine is initially started, we use a very simple * gdt from rom (that in entry32.inc) which only contains those * entries we need for protected mode. * * When we're executing code from RAM, we want to do more complex * stuff, like initializing PCI option roms in real mode, or doing * a resume from a suspend to ram. */ gdt: /* selgdt 0, unused */ .word 0x0000, 0x0000 /* dummy */ .byte 0x00, 0x00, 0x00, 0x00 /* selgdt 8, unused */ .word 0x0000, 0x0000 /* dummy */ .byte 0x00, 0x00, 0x00, 0x00 /* selgdt 0x10, flat code segment */ .word 0xffff, 0x0000 .byte 0x00, 0x9b, 0xcf, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */ /* selgdt 0x18, flat data segment */ .word 0xffff, 0x0000 #ifdef __x86_64__ .byte 0x00, 0x92, 0xcf, 0x00 #else .byte 0x00, 0x93, 0xcf, 0x00 #endif /* selgdt 0x20, unused */ .word 0x0000, 0x0000 /* dummy */ .byte 0x00, 0x00, 0x00, 0x00 /* The next two entries are used for executing VGA option ROMs */ /* selgdt 0x28 16 bit 64k code at 0x00000000 */ .word 0xffff, 0x0000 .byte 0, 0x9a, 0, 0 /* selgdt 0x30 16 bit 64k data at 0x00000000 */ .word 0xffff, 0x0000 .byte 0, 0x92, 0, 0 /* The next two entries are used for ACPI S3 RESUME */ /* selgdt 0x38, flat data segment 16 bit */ .word 0x0000, 0x0000 /* dummy */ .byte 0x00, 0x93, 0x8f, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */ /* selgdt 0x40, flat code segment 16 bit */ .word 0xffff, 0x0000 .byte 0x00, 0x9b, 0x8f, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */ #ifdef __x86_64__ /* selgdt 0x48, flat x64 code segment */ .word 0xffff, 0x0000 .byte 0x00, 0x9b, 0xaf, 0x00 #endif gdt_end: idtarg: .word _idt_end - _idt - 1 /* limit */ .long _idt .word 0 _idt: .fill 20, 8, 0 # idt is uninitialized _idt_end: #ifdef __x86_64__ SetCodeSelector: .intel_syntax noprefix # save rsp because iret will align it to a 16 byte boundary mov rdx, rsp # use iret to jump to a 64-bit offset in a new code segment # iret will pop cs:rip, flags, then ss:rsp mov ax, ss # need to push ss.. push rax # push ss instuction not valid in x64 mode, so use ax push rsp pushfq push rcx # cx is code segment selector from caller mov rax, offset setCodeSelectorLongJump push rax # the iret will continue at next instruction, with the new cs value loaded iretq setCodeSelectorLongJump: # restore rsp, it might not have been 16-byte aligned on entry mov rsp, rdx ret .att_syntax prefix .previous .code64 #else .previous .code32 #endif