From mboxrd@z Thu Jan  1 00:00:00 1970
From: Simon Glass <sjg@chromium.org>
Date: Tue, 3 Jan 2012 21:24:09 -0800
Subject: [U-Boot] [PATCH 04/17] x86: Rework Global Descriptor Table
	loading
In-Reply-To: <1325477374-6417-5-git-send-email-graeme.russ@gmail.com>
References: <1325477374-6417-1-git-send-email-graeme.russ@gmail.com>
	<1325477374-6417-5-git-send-email-graeme.russ@gmail.com>
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Hi Graeme,

On Sun, Jan 1, 2012 at 8:09 PM, Graeme Russ <graeme.russ@gmail.com> wrote:
>

This probably needs a commit message?

Regards,
Simon

> Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
> ---
> ?arch/x86/cpu/cpu.c | ? 82 +++++++++++++++++++++++++++++++++------------------
> ?1 files changed, 53 insertions(+), 29 deletions(-)
>
> diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
> index 61d0b69..bf55c26 100644
> --- a/arch/x86/cpu/cpu.c
> +++ b/arch/x86/cpu/cpu.c
> @@ -55,35 +55,39 @@ struct gdt_ptr {
> ? ? ? ?u32 ptr;
> ?} __packed;
>
> -static void reload_gdt(void)
> +static void load_ds(u32 segment)
> ?{
> - ? ? ? /*
> - ? ? ? ?* There are machines which are known to not boot with the GDT
> - ? ? ? ?* being 8-byte unaligned. ?Intel recommends 16 byte alignment
> - ? ? ? ?*/
> - ? ? ? static const u64 boot_gdt[] __attribute__((aligned(16))) = {
> - ? ? ? ? ? ? ? /* CS: code, read/execute, 4 GB, base 0 */
> - ? ? ? ? ? ? ? [GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
> - ? ? ? ? ? ? ? /* DS: data, read/write, 4 GB, base 0 */
> - ? ? ? ? ? ? ? [GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
> - ? ? ? ? ? ? ? /* 16-bit CS: code, read/execute, 64 kB, base 0 */
> - ? ? ? ? ? ? ? [GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff),
> - ? ? ? ? ? ? ? /* 16-bit DS: data, read/write, 64 kB, base 0 */
> - ? ? ? ? ? ? ? [GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff),
> - ? ? ? };
> - ? ? ? static struct gdt_ptr gdt;
> -
> - ? ? ? gdt.len = sizeof(boot_gdt)-1;
> - ? ? ? gdt.ptr = (u32)&boot_gdt;
> -
> - ? ? ? asm volatile("lgdtl %0\n" \
> - ? ? ? ? ? ? ? ? ? ?"movl $((2+1)*8), %%ecx\n" \
> - ? ? ? ? ? ? ? ? ? ?"movl %%ecx, %%ds\n" \
> - ? ? ? ? ? ? ? ? ? ?"movl %%ecx, %%es\n" \
> - ? ? ? ? ? ? ? ? ? ?"movl %%ecx, %%fs\n" \
> - ? ? ? ? ? ? ? ? ? ?"movl %%ecx, %%gs\n" \
> - ? ? ? ? ? ? ? ? ? ?"movl %%ecx, %%ss" \
> - ? ? ? ? ? ? ? ? ? ?: : "m" (gdt) : "ecx");
> + ? ? ? asm volatile("movl %0, %%ds" : : "r" (segment * 8));
> +}
> +
> +static void load_es(u32 segment)
> +{
> + ? ? ? asm volatile("movl %0, %%es" : : "r" (segment * 8));
> +}
> +
> +static void load_fs(u32 segment)
> +{
> + ? ? ? asm volatile("movl %0, %%fs" : : "r" (segment * 8));
> +}
> +
> +static void load_gs(u32 segment)
> +{
> + ? ? ? asm volatile("movl %0, %%gs" : : "r" (segment * 8));
> +}
> +
> +static void load_ss(u32 segment)
> +{
> + ? ? ? asm volatile("movl %0, %%ss" : : "r" (segment * 8));
> +}
> +
> +static void load_gdt(const u64 *boot_gdt, u16 num_entries)
> +{
> + ? ? ? struct gdt_ptr gdt;
> +
> + ? ? ? gdt.len = (num_entries * 8) - 1;
> + ? ? ? gdt.ptr = (u32)boot_gdt;
> +
> + ? ? ? asm volatile("lgdtl %0\n" : : "m" (gdt));
> ?}
>
> ?int x86_cpu_init_f(void)
> @@ -113,7 +117,27 @@ int x86_cpu_init_r(void)
> ? ? ? ? ? ?"movl ? ? ? %%eax, %%cr0\n"
> ? ? ? ? ? ?"wbinvd\n" : : "i" (nw_cd_rst) : "eax");
>
> - ? ? ? reload_gdt();
> + ? ? ? /*
> + ? ? ? ?* There are machines which are known to not boot with the GDT
> + ? ? ? ?* being 8-byte unaligned. Intel recommends 16 byte alignment
> + ? ? ? ?*/
> + ? ? ? static const u64 boot_gdt[] __aligned(16) = {
> + ? ? ? ? ? ? ? /* CS: code, read/execute, 4 GB, base 0 */
> + ? ? ? ? ? ? ? [GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
> + ? ? ? ? ? ? ? /* DS: data, read/write, 4 GB, base 0 */
> + ? ? ? ? ? ? ? [GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
> + ? ? ? ? ? ? ? /* 16-bit CS: code, read/execute, 64 kB, base 0 */
> + ? ? ? ? ? ? ? [GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff),
> + ? ? ? ? ? ? ? /* 16-bit DS: data, read/write, 64 kB, base 0 */
> + ? ? ? ? ? ? ? [GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff),
> + ? ? ? };
> +
> + ? ? ? load_gdt(boot_gdt, GDT_NUM_ENTRIES);
> + ? ? ? load_ds(GDT_ENTRY_32BIT_DS);
> + ? ? ? load_es(GDT_ENTRY_32BIT_DS);
> + ? ? ? load_fs(GDT_ENTRY_32BIT_DS);
> + ? ? ? load_gs(GDT_ENTRY_32BIT_DS);
> + ? ? ? load_ss(GDT_ENTRY_32BIT_DS);
>
> ? ? ? ?/* Initialize core interrupt and exception functionality of CPU */
> ? ? ? ?cpu_init_interrupts();
> --
> 1.7.5.2.317.g391b14
>
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