minix/kernel/arch/i386/klib.S

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/* sections */
#include <minix/config.h>
#include <minix/const.h>
#include <machine/asm.h>
#include <machine/interrupt.h>
#include <i386/vm.h>
#include "archconst.h"
2010-04-02 00:22:33 +02:00
#include "kernel/const.h"
#include "sconst.h"
#include "multiboot.h"
/*
* This file contains a number of assembly code utility routines needed by the
* kernel.
*/
/*
* The routines only guarantee to preserve the registers the C compiler
* expects to be preserved (ebx, esi, edi, ebp, esp, segment registers, and
* direction bit in the flags).
*/
/*===========================================================================*/
/* monitor */
/*===========================================================================*/
/* PUBLIC void monitor(); */
/* exit Minix and return to the monitor */
ENTRY(monitor)
movl _C_LABEL(mon_sp), %esp /* restore monitor stack pointer */
movw $SS_SELECTOR, %dx /* monitor data segment */
mov %dx, %ds
mov %dx, %es
mov %dx, %fs
mov %dx, %gs
mov %dx, %ss
pop %edi
pop %esi
pop %ebp
lretw /* return to the monitor */
/*===========================================================================*/
/* int86 */
/*===========================================================================*/
/* PUBLIC void int86(); */
/* let the monitor make an 8086 interrupt call */
ENTRY(int86)
cmpb $0, _C_LABEL(mon_return) /* is the monitor there? */
jne 0f
movb $0x01, %ah /* an int 13 error seems appropriate */
movb %ah, _C_LABEL(reg86)+0 /* reg86.w.f = 1 (set carry flag) */
movb %ah, _C_LABEL(reg86)+13 /* reg86.b.ah = 0x01 = "invalid command" */
ret
0:
push %ebp /* save C registers */
push %esi
push %edi
push %ebx
pushf /* save flags */
cli /* no interruptions */
inb $INT2_CTLMASK
movb %al, %ah
inb $INT_CTLMASK
push %eax /* save interrupt masks */
movl _C_LABEL(irq_use), %eax /* map of in-use IRQ's */
and $~(1<<CLOCK_IRQ), %eax /* keep the clock ticking */
outb $INT_CTLMASK /* enable all unused IRQ's and vv. */
movb %ah, %al
outb $INT2_CTLMASK
mov $SS_SELECTOR, %eax /* monitor data segment */
mov %ax, %ss
xchgl _C_LABEL(mon_sp), %esp /* switch stacks */
push _C_LABEL(reg86)+36 /* parameters used in INT call */
push _C_LABEL(reg86)+32
push _C_LABEL(reg86)+28
push _C_LABEL(reg86)+24
push _C_LABEL(reg86)+20
push _C_LABEL(reg86)+16
push _C_LABEL(reg86)+12
push _C_LABEL(reg86)+8
push _C_LABEL(reg86)+4
push _C_LABEL(reg86)+0
mov %ax, %ds /* remaining data selectors */
mov %ax, %es
mov %ax, %fs
mov %ax, %gs
push %cs
push $return /* kernel return address and selector */
ljmpw *20+2*4+10*4+2*4(%esp)
return:
pop _C_LABEL(reg86)+0
pop _C_LABEL(reg86)+4
pop _C_LABEL(reg86)+8
pop _C_LABEL(reg86)+12
pop _C_LABEL(reg86)+16
pop _C_LABEL(reg86)+20
pop _C_LABEL(reg86)+24
pop _C_LABEL(reg86)+28
pop _C_LABEL(reg86)+32
pop _C_LABEL(reg86)+36
lgdt _C_LABEL(gdt)+GDT_SELECTOR /* reload global descriptor table */
ljmp $CS_SELECTOR, $csinit
csinit:
mov $DS_SELECTOR, %eax
mov %ax, %ds
mov %ax, %es
mov %ax, %fs
mov %ax, %gs
mov %ax, %ss
xchgl _C_LABEL(mon_sp), %esp /* unswitch stacks */
lidt _C_LABEL(gdt)+IDT_SELECTOR /* reload interrupt descriptor table */
#ifdef CONFIG_APIC
cmpl $0x0, lapic_addr
jne 3f
mov $0, %ebx
jmp 4f
3:
mov $FLAT_DS_SELECTOR, %ebx
mov %bx, %fs
movl lapic_addr, %eax
add $0x20, %eax
.byte 0x64; mov (%eax), %ebx
and $0xFF000000, %ebx
shr $24, %ebx
movzb %bl, %ebx
4:
add $apicid2cpuid, %ebx
movzb (%ebx), %eax
shl $3, %eax
mov %eax, %ebx
add $TSS_SELECTOR, %eax
addl _C_LABEL(gdt)+DESC_ACCESS, %eax
and $~0x02, %eax
ltr %bx /* set TSS register */
mov $DS_SELECTOR, %eax
mov %ax, %fs
#endif /* CONFIG_APIC */
pop %eax
outb $INT_CTLMASK /* restore interrupt masks */
movb %ah, %al
outb $INT2_CTLMASK
6:
addl %ecx, _C_LABEL(lost_ticks) /* record lost clock ticks */
popf /* restore flags */
pop %ebx /* restore C registers */
pop %edi
pop %esi
pop %ebp
ret
/*===========================================================================*/
/* exit */
/*===========================================================================*/
/*
* PUBLIC void exit();
* Some library routines use exit, so provide a dummy version.
* Actual calls to exit cannot occur in the kernel.
* GNU CC likes to call ___main from main() for nonobvious reasons.
*/
#ifdef __ACK__
ENTRY(exit)
ENTRY(_exit)
ENTRY(__exit)
sti
jmp _C_LABEL(__exit)
#endif
ENTRY(__main)
ret
/*===========================================================================*/
/* phys_insw */
/*===========================================================================*/
/*
* PUBLIC void phys_insw(Port_t port, phys_bytes buf, size_t count);
* Input an array from an I/O port. Absolute address version of insw().
*/
/* transfer data from (disk controller) port to memory */
ENTRY(phys_insw)
push %ebp
mov %esp, %ebp
cld
push %edi
push %es
mov $FLAT_DS_SELECTOR, %ecx
mov %cx, %es
mov 8(%ebp), %edx /* port to read from */
mov 12(%ebp), %edi /* destination addr */
mov 16(%ebp), %ecx /* byte count */
shr $1, %ecx /* word count */
rep insw /* input many words */
pop %es
pop %edi
pop %ebp
ret
/*===========================================================================*/
/* phys_insb */
/*===========================================================================*/
/*
* PUBLIC void phys_insb(Port_t port, phys_bytes buf, size_t count);
* Input an array from an I/O port. Absolute address version of insb().
*/
/* transfer data from (disk controller) port to memory byte by byte */
ENTRY(phys_insb)
push %ebp
mov %esp, %ebp
cld
push %edi
push %es
mov $FLAT_DS_SELECTOR, %ecx
mov %cx, %es
mov 8(%ebp), %edx /* port to read from */
mov 12(%ebp), %edi /* destination addr */
mov 16(%ebp), %ecx /* byte count */
rep insb /* input many bytes */
pop %es
pop %edi
pop %ebp
ret
/*===========================================================================*/
/* phys_outsw */
/*===========================================================================*/
/*
* PUBLIC void phys_outsw(Port_t port, phys_bytes buf, size_t count);
* Output an array to an I/O port. Absolute address version of outsw().
*/
/* transfer data from memory to (disk controller) port */
ENTRY(phys_outsw)
push %ebp
mov %esp, %ebp
cld
push %esi
push %ds
mov $FLAT_DS_SELECTOR, %ecx
mov %cx, %ds
mov 8(%ebp), %edx /* port to write to */
mov 12(%ebp), %esi /* source addr */
mov 16(%ebp), %ecx /* byte count */
shr $1, %ecx /* word count */
rep outsw /* output many words */
pop %ds
pop %esi
pop %ebp
ret
/*===========================================================================*/
/* phys_outsb */
/*===========================================================================*/
/*
* PUBLIC void phys_outsb(Port_t port, phys_bytes buf, size_t count);
* Output an array to an I/O port. Absolute address version of outsb().
*/
/* transfer data from memory to (disk controller) port byte by byte */
ENTRY(phys_outsb)
push %ebp
mov %esp, %ebp
cld
push %esi
push %ds
mov $FLAT_DS_SELECTOR, %ecx
mov %cx, %ds
mov 8(%ebp), %edx /* port to write to */
mov 12(%ebp), %esi /* source addr */
mov 16(%ebp), %ecx /* byte count */
rep outsb /* output many bytes */
pop %ds
pop %esi
pop %ebp
ret
/*===========================================================================*/
/* phys_copy */
/*===========================================================================*/
/*
* PUBLIC phys_bytes phys_copy(phys_bytes source, phys_bytes destination,
* phys_bytes bytecount);
* Copy a block of data from anywhere to anywhere in physical memory.
*/
PC_ARGS = 4+4+4+4 /* 4 + 4 + 4 */
/* es edi esi eip src dst len */
ENTRY(phys_copy)
cld
push %esi
push %edi
push %es
mov $FLAT_DS_SELECTOR, %eax
mov %ax, %es
mov PC_ARGS(%esp), %esi
mov PC_ARGS+4(%esp), %edi
mov PC_ARGS+4+4(%esp), %eax
cmp $10, %eax /* avoid align overhead for small counts */
jb pc_small
mov %esi, %ecx /* align source, hope target is too */
neg %ecx
and $3, %ecx /* count for alignment */
sub %ecx, %eax
rep movsb %es:(%esi), %es:(%edi)
mov %eax, %ecx
shr $2, %ecx /* count of dwords */
rep movsl %es:(%esi), %es:(%edi)
and $3, %eax
pc_small:
xchg %eax, %ecx /* remainder */
rep movsb %es:(%esi), %es:(%edi)
mov $0, %eax /* 0 means: no fault */
LABEL(phys_copy_fault) /* kernel can send us here */
pop %es
pop %edi
pop %esi
ret
LABEL(phys_copy_fault_in_kernel) /* kernel can send us here */
Complete ovehaul of mode switching code - after a trap to kernel, the code automatically switches to kernel stack, in the future local to the CPU - k_reenter variable replaced by a test whether the CS is kernel cs or not. The information is passed further if needed. Removes a global variable which would need to be cpu local - no need for global variables describing the exception or trap context. This information is kept on stack and a pointer to this structure is passed to the C code as a single structure - removed loadedcr3 variable and its use replaced by reading the %cr3 register - no need to redisable interrupts in restart() as they are already disabled. - unified handling of traps that push and don't push errorcode - removed save() function as the process context is not saved directly to process table but saved as required by the trap code. Essentially it means that save() code is inlined everywhere not only in the exception handling routine - returning from syscall is more arch independent - it sets the retger in C - top of the x86 stack contains the current CPU id and pointer to the currently scheduled process (the one right interrupted) so the mode switch code can find where to save the context without need to use proc_ptr which will be cpu local in the future and therefore difficult to access in assembler and expensive to access in general - some more clean up of level0 code. No need to read-back the argument passed in %eax from the proc structure. The mode switch code does not clobber %the general registers and hence we can just call what is in %eax - many assebly macros in sconst.h as they will be reused by the apic assembly
2009-11-06 10:08:26 +01:00
pop %es
pop %edi
pop %esi
mov %cr2, %eax
ret
/*===========================================================================*/
/* copy_msg_from_user */
/*===========================================================================*/
/*
* int copy_msg_from_user(struct proc * p, message * user_mbuf, message * dst);
*
* Copies a message of 36 bytes from user process space to a kernel buffer. This
* function assumes that the process address space is installed (cr3 loaded) and
* the local descriptor table of this process is loaded too.
*
* The %gs segment register is used to access the userspace memory. We load the
* process' data segment in this register.
*
* This function from the callers point of view either succeeds or returns an
* error which gives the caller a chance to respond accordingly. In fact it
* either succeeds or if it generates a pagefault, general protection or other
* exception, the trap handler has to redirect the execution to
* __user_copy_msg_pointer_failure where the error is reported to the caller
* without resolving the pagefault. It is not kernel's problem to deal with
* wrong pointers from userspace and the caller should return an error to
* userspace as if wrong values or request were passed to the kernel
*/
ENTRY(copy_msg_from_user)
push %gs
mov 8(%esp), %eax
movw DSREG(%eax), %gs
/* load the source pointer */
mov 12(%esp), %ecx
/* load the destination pointer */
mov 16(%esp), %edx
mov %gs:0*4(%ecx), %eax
mov %eax, 0*4(%edx)
mov %gs:1*4(%ecx), %eax
mov %eax, 1*4(%edx)
mov %gs:2*4(%ecx), %eax
mov %eax, 2*4(%edx)
mov %gs:3*4(%ecx), %eax
mov %eax, 3*4(%edx)
mov %gs:4*4(%ecx), %eax
mov %eax, 4*4(%edx)
mov %gs:5*4(%ecx), %eax
mov %eax, 5*4(%edx)
mov %gs:6*4(%ecx), %eax
mov %eax, 6*4(%edx)
mov %gs:7*4(%ecx), %eax
mov %eax, 7*4(%edx)
mov %gs:8*4(%ecx), %eax
mov %eax, 8*4(%edx)
LABEL(__copy_msg_from_user_end)
pop %gs
movl $0, %eax
ret
/*===========================================================================*/
/* copy_msg_to_user */
/*===========================================================================*/
/*
* void copy_msg_to_user(struct proc * p, message * src, message * user_mbuf);
*
* Copies a message of 36 bytes to user process space from a kernel buffer. This
* function assumes that the process address space is installed (cr3 loaded) and
* the local descriptor table of this process is loaded too.
*
* All the other copy_msg_from_user() comments apply here as well!
*/
ENTRY(copy_msg_to_user)
push %gs
mov 8(%esp), %eax
movw DSREG(%eax), %gs
/* load the source pointer */
mov 12(%esp), %ecx
/* load the destination pointer */
mov 16(%esp), %edx
mov 0*4(%ecx), %eax
mov %eax, %gs:0*4(%edx)
mov 1*4(%ecx), %eax
mov %eax, %gs:1*4(%edx)
mov 2*4(%ecx), %eax
mov %eax, %gs:2*4(%edx)
mov 3*4(%ecx), %eax
mov %eax, %gs:3*4(%edx)
mov 4*4(%ecx), %eax
mov %eax, %gs:4*4(%edx)
mov 5*4(%ecx), %eax
mov %eax, %gs:5*4(%edx)
mov 6*4(%ecx), %eax
mov %eax, %gs:6*4(%edx)
mov 7*4(%ecx), %eax
mov %eax, %gs:7*4(%edx)
mov 8*4(%ecx), %eax
mov %eax, %gs:8*4(%edx)
LABEL(__copy_msg_to_user_end)
pop %gs
movl $0, %eax
ret
/*
* if a function from a selected set of copies from or to userspace fails, it is
* because of a wrong pointer supplied by the userspace. We have to clean up and
* and return -1 to indicated that something wrong has happend. The place it was
* called from has to handle this situation. The exception handler redirect us
* here to continue, clean up and report the error
*/
ENTRY(__user_copy_msg_pointer_failure)
pop %gs
movl $-1, %eax
ret
/*===========================================================================*/
/* phys_memset */
/*===========================================================================*/
/*
* PUBLIC void phys_memset(phys_bytes source, unsigned long pattern,
* phys_bytes bytecount);
* Fill a block of physical memory with pattern.
*/
ENTRY(phys_memset)
push %ebp
mov %esp, %ebp
push %esi
push %ebx
push %ds
mov 8(%ebp), %esi
mov 16(%ebp), %eax
mov $FLAT_DS_SELECTOR, %ebx
mov %bx, %ds
mov 12(%ebp), %ebx
shr $2, %eax
fill_start:
mov %ebx, (%esi)
add $4, %esi
dec %eax
jne fill_start
/* Any remaining bytes? */
mov 16(%ebp), %eax
and $3, %eax
remain_fill:
cmp $0, %eax
je fill_done
movb 12(%ebp), %bl
movb %bl, (%esi)
add $1, %esi
inc %ebp
dec %eax
jmp remain_fill
fill_done:
pop %ds
pop %ebx
pop %esi
pop %ebp
ret
/*===========================================================================*/
/* mem_rdw */
/*===========================================================================*/
/*
* PUBLIC u16_t mem_rdw(U16_t segment, u16_t *offset);
* Load and return word at far pointer segment:offset.
*/
ENTRY(mem_rdw)
mov %ds, %cx
mov 4(%esp), %ds
mov 4+4(%esp), %eax /* offset */
movzwl (%eax), %eax /* word to return */
mov %cx, %ds
ret
/*===========================================================================*/
/* reset */
/*===========================================================================*/
/*
* PUBLIC void reset();
* Reset the system by loading IDT with offset 0 and interrupting.
*/
ENTRY(reset)
lidt idt_zero
int $3 /* anything goes, the 386 will not like it */
.data
idt_zero:
.long 0, 0
.text
/*===========================================================================*/
/* halt_cpu */
/*===========================================================================*/
/*
* PUBLIC void halt_cpu(void);
* reanables interrupts and puts the cpu in the halts state. Once an interrupt
* is handled the execution resumes by disabling interrupts and continues
*/
ENTRY(halt_cpu)
sti
hlt /* interrupts enabled only after this instruction is executed! */
/*
* interrupt handlers make sure that the interrupts are disabled when we
* get here so we take only _one_ interrupt after halting the CPU
*/
ret
/*===========================================================================*/
/* read_flags */
/*===========================================================================*/
/*
* PUBLIC unsigned long read_cpu_flags(void);
* Read CPU status flags from C.
*/
ENTRY(read_cpu_flags)
pushf
mov (%esp), %eax
add $4, %esp
ret
ENTRY(read_ds)
mov $0, %eax
mov %ds, %ax
ret
ENTRY(read_cs)
mov $0, %eax
mov %cs, %ax
ret
ENTRY(read_ss)
mov $0, %eax
mov %ss, %ax
ret
/*===========================================================================*/
/* fpu_routines */
/*===========================================================================*/
/* non-waiting FPU initialization */
ENTRY(fninit)
fninit
ret
ENTRY(clts)
clts
ret
/* store status word (non-waiting) */
ENTRY(fnstsw)
xor %eax, %eax
/* DO NOT CHANGE THE OPERAND!!! gas2ack does not handle it yet */
fnstsw %ax
ret
/* store control word (non-waiting) */
ENTRY(fnstcw)
push %eax
mov 8(%esp), %eax
/* DO NOT CHANGE THE OPERAND!!! gas2ack does not handle it yet */
fnstcw (%eax)
pop %eax
ret
/*===========================================================================*/
/* fxsave */
/*===========================================================================*/
ENTRY(fxsave)
mov 4(%esp), %eax
fxsave (%eax) /* Do not change the operand! (gas2ack) */
ret
/*===========================================================================*/
/* fnsave */
/*===========================================================================*/
ENTRY(fnsave)
mov 4(%esp), %eax
fnsave (%eax) /* Do not change the operand! (gas2ack) */
fwait /* required for compatibility with processors prior pentium */
ret
/*===========================================================================*/
/* fxrstor */
/*===========================================================================*/
ENTRY(fxrstor)
mov 4(%esp), %eax
fxrstor (%eax) /* Do not change the operand! (gas2ack) */
ret
/*===========================================================================*/
/* frstor */
/*===========================================================================*/
ENTRY(frstor)
mov 4(%esp), %eax
frstor (%eax) /* Do not change the operand! (gas2ack) */
ret
/*===========================================================================*/
/* read_cr0 */
/*===========================================================================*/
/* PUBLIC unsigned long read_cr0(void); */
ENTRY(read_cr0)
push %ebp
mov %esp, %ebp
mov %cr0, %eax
pop %ebp
ret
/*===========================================================================*/
/* write_cr0 */
/*===========================================================================*/
/* PUBLIC void write_cr0(unsigned long value); */
ENTRY(write_cr0)
push %ebp
mov %esp, %ebp
mov 8(%ebp), %eax
mov %eax, %cr0
jmp 0f /* A jump is required for some flags */
0:
pop %ebp
ret
Complete ovehaul of mode switching code - after a trap to kernel, the code automatically switches to kernel stack, in the future local to the CPU - k_reenter variable replaced by a test whether the CS is kernel cs or not. The information is passed further if needed. Removes a global variable which would need to be cpu local - no need for global variables describing the exception or trap context. This information is kept on stack and a pointer to this structure is passed to the C code as a single structure - removed loadedcr3 variable and its use replaced by reading the %cr3 register - no need to redisable interrupts in restart() as they are already disabled. - unified handling of traps that push and don't push errorcode - removed save() function as the process context is not saved directly to process table but saved as required by the trap code. Essentially it means that save() code is inlined everywhere not only in the exception handling routine - returning from syscall is more arch independent - it sets the retger in C - top of the x86 stack contains the current CPU id and pointer to the currently scheduled process (the one right interrupted) so the mode switch code can find where to save the context without need to use proc_ptr which will be cpu local in the future and therefore difficult to access in assembler and expensive to access in general - some more clean up of level0 code. No need to read-back the argument passed in %eax from the proc structure. The mode switch code does not clobber %the general registers and hence we can just call what is in %eax - many assebly macros in sconst.h as they will be reused by the apic assembly
2009-11-06 10:08:26 +01:00
/*===========================================================================*/
/* read_cr2 */
/*===========================================================================*/
/* PUBLIC reg_t read_cr2(void); */
ENTRY(read_cr2)
Complete ovehaul of mode switching code - after a trap to kernel, the code automatically switches to kernel stack, in the future local to the CPU - k_reenter variable replaced by a test whether the CS is kernel cs or not. The information is passed further if needed. Removes a global variable which would need to be cpu local - no need for global variables describing the exception or trap context. This information is kept on stack and a pointer to this structure is passed to the C code as a single structure - removed loadedcr3 variable and its use replaced by reading the %cr3 register - no need to redisable interrupts in restart() as they are already disabled. - unified handling of traps that push and don't push errorcode - removed save() function as the process context is not saved directly to process table but saved as required by the trap code. Essentially it means that save() code is inlined everywhere not only in the exception handling routine - returning from syscall is more arch independent - it sets the retger in C - top of the x86 stack contains the current CPU id and pointer to the currently scheduled process (the one right interrupted) so the mode switch code can find where to save the context without need to use proc_ptr which will be cpu local in the future and therefore difficult to access in assembler and expensive to access in general - some more clean up of level0 code. No need to read-back the argument passed in %eax from the proc structure. The mode switch code does not clobber %the general registers and hence we can just call what is in %eax - many assebly macros in sconst.h as they will be reused by the apic assembly
2009-11-06 10:08:26 +01:00
mov %cr2, %eax
ret
/*===========================================================================*/
/* read_cr3 */
/*===========================================================================*/
/* PUBLIC unsigned long read_cr3(void); */
ENTRY(read_cr3)
push %ebp
mov %esp, %ebp
/* DO NOT CHANGE THE OPERAND!!! gas2ack does not handle it yet */
mov %cr3, %eax
pop %ebp
ret
/*===========================================================================*/
/* read_cr4 */
/*===========================================================================*/
/* PUBLIC unsigned long read_cr4(void); */
ENTRY(read_cr4)
push %ebp
mov %esp, %ebp
/* DO NOT CHANGE THE OPERAND!!! gas2ack does not handle it yet */
mov %cr4, %eax
pop %ebp
ret
/*===========================================================================*/
/* write_cr4 */
/*===========================================================================*/
/* PUBLIC void write_cr4(unsigned long value); */
ENTRY(write_cr4)
push %ebp
mov %esp, %ebp
mov 8(%ebp), %eax
/* DO NOT CHANGE THE OPERAND!!! gas2ack does not handle it yet */
mov %eax, %cr4
jmp 0f
0:
pop %ebp
ret
/*===========================================================================*/
/* write_cr3 */
/*===========================================================================*/
/* PUBLIC void write_cr3(unsigned long value); */
ENTRY(write_cr3)
push %ebp
mov %esp, %ebp
mov 8(%ebp), %eax
/* DO NOT CHANGE THE OPERAND!!! gas2ack does not handle it yet */
mov %eax, %cr3
pop %ebp
ret
/*===========================================================================*/
/* getcr3val */
/*===========================================================================*/
/* PUBLIC unsigned long getcr3val(void); */
ENTRY(getcr3val)
mov %cr3, %eax
ret
/*
* Read the Model Specific Register (MSR) of IA32 architecture
*
* void ia32_msr_read(u32_t reg, u32_t * hi, u32_t * lo)
*/
ENTRY(ia32_msr_read)
push %ebp
mov %esp, %ebp
mov 8(%ebp), %ecx
rdmsr
mov 12(%ebp), %ecx
mov %edx, (%ecx)
mov 16(%ebp), %ecx
mov %eax, (%ecx)
pop %ebp
ret
/*
* Write the Model Specific Register (MSR) of IA32 architecture
*
* void ia32_msr_write(u32_t reg, u32_t hi, u32_t lo)
*/
ENTRY(ia32_msr_write)
push %ebp
mov %esp, %ebp
mov 12(%ebp), %edx
mov 16(%ebp), %eax
mov 8(%ebp), %ecx
wrmsr
pop %ebp
ret
/*===========================================================================*/
/* idt_reload */
/*===========================================================================*/
/* PUBLIC void idt_reload (void); */
/* reload idt when returning to monitor. */
ENTRY(idt_reload)
lidt _C_LABEL(gdt)+IDT_SELECTOR /* reload interrupt descriptor table */
ret
/*
* void reload_segment_regs(void)
*/
#define RELOAD_SEG_REG(reg) \
mov reg, %ax ;\
mov %ax, reg ;
ENTRY(reload_ds)
RELOAD_SEG_REG(%ds)
ret
/*===========================================================================*/
/* switch_address_space */
/*===========================================================================*/
/* PUBLIC void switch_address_space(struct proc *p)
*
* sets the %cr3 register to the supplied value if it is not already set to the
* same value in which case it would only result in an extra TLB flush which is
* not desirable
*/
ENTRY(switch_address_space)
/* read the process pointer */
mov 4(%esp), %edx
/* enable process' segment descriptors */
lldt P_LDT_SEL(%edx)
/* get the new cr3 value */
movl P_CR3(%edx), %eax
/* test if the new cr3 != NULL */
cmpl $0, %eax
je 0f
/*
* test if the cr3 is loaded with the current value to avoid unnecessary
* TLB flushes
*/
mov %cr3, %ecx
cmp %ecx, %eax
je 0f
mov %eax, %cr3
mov %edx, _C_LABEL(ptproc)
0:
ret
/*===========================================================================*/
/* poweroff */
/*===========================================================================*/
/* PUBLIC void poweroff(); */
/* Jump to 16-bit poweroff code */
ENTRY(poweroff_jmp)
cli
/* Make real mode descriptor */
mov $(_C_LABEL(gdt) + SS_SELECTOR), %edi
mov $0x100, %eax
movw %ax, 2(%edi)
shr $16, %eax
movb %al, 4(%edi)
and $0xff00, %ax
andw $0xff, 6(%edi)
or %ax, 6(%edi)
mov $0xffff, %eax
movw %ax, (%edi)
shr $16, %eax
and $0xf, %ax
andb $0xf0, 6(%edi)
or %ax, 6(%edi)
/* Flush TLB */
xor %eax, %eax
mov %eax, %cr3
xor %esp, %esp /* clear esp for real mode*/
/* Reset IDTR */
lidt idt_ptr
mov $SS_SELECTOR, %ax
mov %ax, %ds
mov %ax, %es
mov %ax, %fs
mov %ax, %gs
mov %ax, %ss
/* Save real mode cr0 in eax */
mov %cr0, %eax
andl $~I386_CR0_PE, %eax
/* Jump to 16-bit code that is copied to below 1MB */
ljmp $MON_CS_SELECTOR, $0
/* acknowledge just the master PIC */
ENTRY(eoi_8259_master)
movb $END_OF_INT, %al
outb $INT_CTL
ret
/* we have to acknowledge both PICs */
ENTRY(eoi_8259_slave)
movb $END_OF_INT, %al
outb $INT_CTL
outb $INT2_CTL
ret
.data
idt_ptr:
.short 0x3ff
.long 0x0