Re: [PATCH 3/4] Add cpu_number and cpuboot

[Samuel Thibault]

Damien Zammit, le ven. 11 nov. 2022 23:21:28 +0000, a ecrit:
> diff --git a/i386/i386/cpu_number.c b/i386/i386/cpu_number.c
> new file mode 100644
> index 00000000..d4621669
> --- /dev/null
> +++ b/i386/i386/cpu_number.c
> +#if NCPUS > 1
> +int cpu_number(void)
> +{
> +     int kernel_id;
> +     unsigned long flags;
> +
> +     cpu_intr_save(&flags);
> +
> +     kernel_id = apic_get_cpu_kernel_id(apic_get_current_cpu());
> +
> +     cpu_intr_restore(flags);

Why disabling interrupts?

> +     return kernel_id;
> +}
> +#endif
> diff --git a/i386/i386/cpuboot.S b/i386/i386/cpuboot.S
> new file mode 100644
> index 00000000..4a5823be
> --- /dev/null
> +++ b/i386/i386/cpuboot.S
> +     /* 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 (ACC_P | ACC_CODE_R) /*Access byte */
> +     .byte 0xcf /* High 4 bits */

0xc0 should rather be the non-magic (SZ_G|SZ_32) << 4

> +     .byte ((-KERNELBASE) >> 24) & 0xff /*Base 24-31 bits */
> +     /* KERNEL_DS */
> +     .word 0xffff /*Segment limit */
> +     .word (-KERNELBASE) & 0xffff /*Base first 0-15 bits*/
> +     .byte ((-KERNELBASE) >> 16) & 0xff
> +     .byte (ACC_P | ACC_DATA_W) /*Access byte*/
> +     .byte 0xcf /* High 4 bits */

Ditto

> +     .byte ((-KERNELBASE) >> 24) & 0xff /*Base 24-31 bits */


> +.align 16
> +gdt_tmp:
> +    /* 0 */
> +    .quad 0
> +    /* BOOT_CS */
> +    .word 0xffff
> +    .word 0x0000
> +    .byte 0x00
> +    .byte (ACC_P | ACC_CODE_R)
> +    .byte 0xcf

Ditto

> +    .byte 0x00
> +    /* BOOT_DS */
> +    .word 0xffff
> +    .word 0x0000
> +    .byte 0x00
> +    .byte (ACC_P | ACC_DATA_W)
> +    .byte 0xcf

Ditto

> +    .byte 0x00
> +
> +_apbootend:
> +apbootend:


> diff --git a/i386/i386at/boothdr.S b/i386/i386at/boothdr.S
> index 82d4b34a..a4830326 100644
> --- a/i386/i386at/boothdr.S
> +++ b/i386/i386at/boothdr.S
> @@ -58,7 +58,7 @@ boot_entry:
> 
>       /* Reset EFLAGS to a known state.  */
>       pushl   $0
> -     popf
> +     popfl
> 
>       /* Clear uninitialized data.  */
>       lea     _edata,%edi
> --
> 2.34.1
> 
> 
> 

-- 
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.