Damien Zammit, le mar. 25 oct. 2022 10:56:26 +0000, a ecrit: > +apboot_gdt: > + /* NULL segment */ > + .quad 0 > + /* boot CS = 8 . Code Segment*/
? No, it's the actual KERNEL_CS > + .word 0xffff /* Segment limit first 0-15 bits*/ > + .word (-KERNELBASE) & 0xffff /*Base first 0-15 bits*/ > + .byte ((-KERNELBASE) >> 16) & 0xff /*Base 16-23 bits */ > + .byte 0x9a /*Access byte */ > + .byte 0xcf /* High 4 bits */ Rather avoid magic numbers, use ACC_* macros like e.g. i386/i386/idt_inittab.S does. > + .byte ((-KERNELBASE) >> 24) & 0xff /*Base 24-31 bits */ > + /* boot DS = 8 . Data segment*/ It's the actual KERNEL_DS > + .word 0xffff /*Segment limit */ > + .word (-KERNELBASE) & 0xffff /*Base first 0-15 bits*/ > + .byte ((-KERNELBASE) >> 16) & 0xff > + .byte 0x92 /*Access byte*/ > + .byte 0xcf /* High 4 bits */ > + .byte ((-KERNELBASE) >> 24) & 0xff /*Base 24-31 bits */ > + > +.globl apboot, apbootend > +.align 16 > +.code16 > + > +apboot: > +_apboot: > + cli > + xorl %eax, %eax > + movl %eax, %cr3 > + mov %ax, %ds > + mov %ax, %es > + mov %ax, %ss > + > + lgdt M(gdt_descr_tmp) > + > + movl %cr0, %eax > + andl $~CR0_CLEAR_FLAGS, %eax > + orl $CR0_SET_FLAGS, %eax > + movl %eax, %cr0 > + > + ljmp $KERNEL_CS, $M(0f) > +0: > + .code32 > + movw $0, %ax Rather use a BOOT_CS/DS macro > + movw %ax, %ds > + movw %ax, %es > + movw %ax, %fs > + movw %ax, %gs Rather set these to BOOT_DS only? > + movw $16, %ax > + movw %ax, %ds > + movw %ax, %es > + movw %ax, %ss > + > + lgdtl apboot_gdt_descr - KERNELBASE > + ljmpl $KERNEL_CS, $1f > +1: > + movw $KERNEL_DS, %ax > + movw %ax, %ds > + movw %ax, %es > + movw %ax, %ss Also set fs and gs to be safe. > + /* Load null Interrupt descriptor table */ > + mov apboot_idt_ptr, %ebx > + lidt (%ebx) > + > + /* Enable local apic */ Is it needed here, can't we do it in C? > + xorl %eax, %eax > + xorl %edx, %edx > + movl $APIC_MSR, %ecx > + rdmsr > + orl $APIC_MSR_ENABLE, %eax > + andl $(~APIC_MSR_BSP), %eax > + movl $APIC_MSR, %ecx > + wrmsr > + > + /* Load int_stack_top[cpu] -> esp */ > + CPU_NUMBER(%edx) > + movl CX(EXT(int_stack_top), %edx), %esp > + > + /* Ensure stack alignment */ > + andl $0xfffffff0, %esp > + > + /* Reset EFLAGS to a known state */ > + pushl $0 > + popf > + > + /* Finish the cpu configuration */ > + call EXT(cpu_ap_main) > + > + /* NOT REACHED */ > + hlt > + > +.align 16 > + .word 0 > +gdt_descr_tmp: > + .short 3*8+7 > + .long M(gdt_tmp) > + > +.align 16 > +gdt_tmp: > + /* 0 */ > + .quad 0 > + /* boot CS = 0x8 */ > + .word 0xffff > + .word 0x0000 > + .byte 0x00 > + .byte 0x9a > + .byte 0xcf Ditto for magic numbers. > + .byte 0x00 > + /* boot DS = 0x10 */ > + .word 0xffff > + .word 0x0000 > + .byte 0x00 > + .byte 0x92 > + .byte 0xcf > + .byte 0x00 > + > +_apbootend: > +apbootend: > -- > 2.34.1 > > > -- Samuel --- Pour une évaluation indépendante, transparente et rigoureuse ! Je soutiens la Commission d'Évaluation de l'Inria.
