On Tue, Aug 11, 2015 at 10:44 AM, Simon Glass sjg@chromium.org wrote:

Some archs like to have larger alignment for their global data. Use 16 bytes which suits all current archs.

Signed-off-by: Simon Glass sjg@chromium.org

Changes in v2:

• Correct logic to round down instead of up

common/board_f.c | 1 + include/asm-generic/global_data.h | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/common/board_f.c b/common/board_f.c index 8cca4de..74f77f1 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -499,6 +499,7 @@ static int setup_machine(void) static int reserve_global_data(void) { gd->start_addr_sp -= sizeof(gd_t);

•   gd->start_addr_sp &= ~0xf;
    gd->new_gd = (gd_t *)map_sysmem(gd->start_addr_sp, sizeof(gd_t));
    debug("Reserving %zu Bytes for Global Data at: %08lx\n",
                    sizeof(gd_t), gd->start_addr_sp);
  

diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h index 2155265..147f646 100644 --- a/include/asm-generic/global_data.h +++ b/include/asm-generic/global_data.h @@ -99,7 +99,7 @@ typedef struct global_data { int pcidelay_done; #endif struct udevice *cur_serial_dev; /* current serial device */

•   struct arch_global_data arch;   /* architecture-specific data */
  

•   struct arch_global_data arch __aligned(16);     /* arch-specific data */
  

} gd_t; #endif

--

Reviewed-by: Bin Meng bmeng.cn@gmail.com

On 11 August 2015 at 00:28, Bin Meng bmeng.cn@gmail.com wrote:

On Tue, Aug 11, 2015 at 10:44 AM, Simon Glass sjg@chromium.org wrote:

...

At present we have a simple assignment to gd. With some archs this is implemented as a register or through some other means; a simple assignment does not suit in all cases.

Change this to a function and add documentation to describe how this all works.

Signed-off-by: Simon Glass sjg@chromium.org Reviewed-by: York Sun yorksun@freescale.com

---

Changes in v2:

• Drop unused 'reserve_size' argument
• Rename arch_setup_gdt() to arch_setup_gd()
• Expand the comment about the 64-byte stack space
• Fix a comma which should be a period
• Add a comment as to why we can't compile the weak arch_setup_gd() on x86

common/board_f.c | 13 +++++++++++-- include/common.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/common/board_f.c b/common/board_f.c index 74f77f1..37b7bf5 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -1027,16 +1027,25 @@ void board_init_f_r(void) } #endif /* CONFIG_X86 */

+/* Unfortunately x86 can't compile this code as gd cannot be assigned */ #ifndef CONFIG_X86 +__weak void arch_setup_gd(struct global_data *gd_ptr) +{

•   gd = gd_ptr;
  

+}

ulong board_init_f_mem(ulong top) {

•   struct global_data *gd_ptr;
  

•   /* Leave space for the stack we are running with now */
    top -= 0x40;
  
    top -= sizeof(struct global_data);
    top = ALIGN(top, 16);
  

•   gd = (struct global_data *)top;
  

•   memset((void *)gd, '\0', sizeof(*gd));
  

•   gd_ptr = (struct global_data *)top;
  

•   memset(gd_ptr, '\0', sizeof(*gd));
  

•   arch_setup_gd(gd_ptr);
  
  

#ifdef CONFIG_SYS_MALLOC_F_LEN top -= CONFIG_SYS_MALLOC_F_LEN; diff --git a/include/common.h b/include/common.h index fcc9ae7..48e5006 100644 --- a/include/common.h +++ b/include/common.h @@ -217,6 +217,49 @@ extern char console_buffer[]; /* arch/$(ARCH)/lib/board.c */ void board_init_f(ulong); void board_init_r(gd_t *, ulong) __attribute__ ((noreturn));

+/**

• • board_init_f_mem() - Allocate global data and set stack position
• • This function is called by each architecture very early in the start-up
• • code to set up the environment for board_init_f(). It allocates space for
• • global_data (see include/asm-generic/global_data.h) and places the stack
• • below this.
• • This function requires a stack[1] Normally this is at @top. The function
• • starts allocating space from 64 bytes below @top. First it creates space
• • for global_data. Then it calls arch_setup_gd() which sets gd to point to
• • the global_data space and can reserve additional bytes of space if
• • required). Finally it allocates early malloc() memory
• • (CONFIG_SYS_MALLOC_F_LEN). The new top of the stack is just below this,
• • and it returned by this function.
• • [1] Strictly speaking it would be possible to implement this function
• • in C on many archs such that it does not require a stack. However this
• • does not seem hugely important as only 64 byte are wasted. The 64 bytes
• • are used to handle the calling standard which generally requires pushing
• • addresses or registers onto the stack. We should be able to get away with
• • less if this becomes important.
• • @top: Top of available memory, also normally the top of the stack
• • @return: New stack location
• */

+ulong board_init_f_mem(ulong top);

+/**

• • arch_setup_gd() - Set up the global_data pointer
• • This pointer is special in some architectures and cannot easily be assigned
• • to. For example on x86 it is implemented by adding a specific record to its
• • Global Descriptor Table! So we we provide a function to carry out this task.
• • For most architectures this can simply be:
• • gd = gd_ptr;
• • @gd_ptr: Pointer to global data
• */

+void arch_setup_gd(gd_t *gd_ptr);

int checkboard(void); int show_board_info(void); int checkflash(void); --

Reviewed-by: Bin Meng bmeng.cn@gmail.com

Applied to u-boot-x86

On Tue, Aug 11, 2015 at 10:44 AM, Simon Glass sjg@chromium.org wrote:

There is quite a bit of assembler code that can be removed if we use the generic global_data setup. Less arch-specific code makes it easier to add new features and maintain the start-up code.

Drop the unneeded code and adjust the hooks in board_f.c to cope.

Signed-off-by: Simon Glass sjg@chromium.org

Changes in v2:

• Don't rely on value of %edx from board_init_f_mem()

arch/x86/cpu/cpu.c | 4 ++- arch/x86/cpu/start.S | 95 +++++++--------------------------------------------- common/board_f.c | 3 +- 3 files changed, 18 insertions(+), 84 deletions(-)

diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c index 4f57145..1b76ca1 100644 --- a/arch/x86/cpu/cpu.c +++ b/arch/x86/cpu/cpu.c @@ -136,8 +136,10 @@ static void load_gdt(const u64 *boot_gdt, u16 num_entries) asm volatile("lgdtl %0\n" : : "m" (gdt)); }

-void setup_gdt(gd_t *new_gd, u64 *gdt_addr) +void arch_setup_gd(gd_t *new_gd) {

•   u64 *gdt_addr;
  

•   gdt_addr = new_gd->arch.gdt;
  
    /* CS: code, read/execute, 4 GB, base 0 */
  

diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S index 313fa3f..e94ddc4 100644 --- a/arch/x86/cpu/start.S +++ b/arch/x86/cpu/start.S @@ -104,8 +104,7 @@ car_init_ret: * * top-> CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE * MRC area

•    *      global_data
  

•    *      x86 global descriptor table
  

•    *      global_data with x86 global descriptor table
     *      early malloc area
     *      stack
     * bottom-> CONFIG_SYS_CAR_ADDR
  

@@ -120,13 +119,10 @@ car_init_ret: * and esi holds the HOB list address returned by the FSP. */ #endif

•   /* Reserve space on stack for global data */
  

•   subl    $GENERATED_GBL_DATA_SIZE, %esp
  

•   /* Align global data to 16-byte boundary */
  

•   andl    $0xfffffff0, %esp
  

•   post_code(POST_START_STACK)
  

•   /* Set up global data */
  

•   mov     %esp, %eax
  

•   call    board_init_f_mem
  

•   mov     %eax, %esp
  
    /*
     * Debug UART is available here although it may not be plumbed out
  

@@ -137,56 +133,21 @@ car_init_ret: * call printch */

•   /* Zero the global data since it won't happen later */
  

•   xorl    %eax, %eax
  

•   movl    $GENERATED_GBL_DATA_SIZE, %ecx
  

•   movl    %esp, %edi
  

•   rep     stosb
  

•   /* Get address of global_data */
  

•   mov     %fs:0, %edx
  

#ifdef CONFIG_HAVE_FSP

•   /* Store the HOB list if we have one */
    test    %esi, %esi
    jz      skip_hob
  

•   /* Store HOB list */
  

•   movl    %esp, %edx
  

•   addl    $GD_HOB_LIST, %edx
  

•   movl    %esi, (%edx)
  

•   movl    %esi, GD_HOB_LIST(%edx)
  
  

skip_hob: #else /* Store table pointer */

•   movl    %esp, %edx
  

•   addl    $GD_TABLE, %edx
  

•   movl    %esi, (%edx)
  

•   movl    %esi, GD_TABLE(%edx)
  

#endif

•   /* Setup first parameter to setup_gdt, pointer to global_data */
  

•   movl    %esp, %eax
  

•   /* Reserve space for global descriptor table */
  

•   subl    $X86_GDT_SIZE, %esp
  

•   /* Align temporary global descriptor table to 16-byte boundary */
  

•   andl    $0xfffffff0, %esp
  

•   movl    %esp, %ecx
  

-#if defined(CONFIG_SYS_MALLOC_F_LEN)

•   /* Set up the pre-relocation malloc pool */
  

•   subl    $CONFIG_SYS_MALLOC_F_LEN, %esp
  

•   movl    %eax, %edx
  

•   addl    $GD_MALLOC_BASE, %edx
  

•   movl    %esp, (%edx)
  

-#endif

•   /* Store BIST into global_data */
  

•   movl    %eax, %edx
  

•   addl    $GD_BIST, %edx
  

•   movl    %ebp, (%edx)
  

•   /* Set second parameter to setup_gdt() */
  

•   movl    %ecx, %edx
  

•   /* Setup global descriptor table so gd->xyz works */
  

•   call    setup_gdt
  

•   /* Store BIST */
  

•   movl    %ebp, GD_BIST(%edx)
  
    /* Set parameter to board_init_f() to boot flags */
    post_code(POST_START_DONE)
  

@@ -213,37 +174,7 @@ board_init_f_r_trampoline: /* Stack grows down from top of SDRAM */ movl %eax, %esp

•   /* Reserve space on stack for global data */
  

•   subl    $GENERATED_GBL_DATA_SIZE, %esp
  

•   /* Align global data to 16-byte boundary */
  

•   andl    $0xfffffff0, %esp
  

•   /* Setup first parameter to memcpy() and setup_gdt() */
  

•   movl    %esp, %eax
  

•   /* Setup second parameter to memcpy() */
  

•   fs movl 0, %edx
  

•   /* Set third parameter to memcpy() */
  

•   movl    $GENERATED_GBL_DATA_SIZE, %ecx
  

•   /* Copy global data from CAR to SDRAM stack */
  

•   call    memcpy
  

•   /* Reserve space for global descriptor table */
  

•   subl    $X86_GDT_SIZE, %esp
  

•   /* Align global descriptor table to 16-byte boundary */
  

•   andl    $0xfffffff0, %esp
  

•   /* Set second parameter to setup_gdt() */
  

•   movl    %esp, %edx
  

•   /* Setup global descriptor table so gd->xyz works */
  

•   call    setup_gdt
  

•   /* Set if we need to disable CAR */
  

•   /* See if we need to disable CAR */
  

.weak car_uninit movl $car_uninit, %eax cmpl $0, %eax diff --git a/common/board_f.c b/common/board_f.c index 37b7bf5..c959774 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -715,6 +715,7 @@ static int jump_to_copy(void) * with the stack in SDRAM and Global Data in temporary memory * (CPU cache) */

•   arch_setup_gd(gd->new_gd);
    board_init_f_r_trampoline(gd->start_addr_sp);
  

#else relocate_code(gd->start_addr_sp, gd->new_gd, gd->relocaddr); @@ -1033,6 +1034,7 @@ __weak void arch_setup_gd(struct global_data *gd_ptr) { gd = gd_ptr; } +#endif /* !CONFIG_X86 */

ulong board_init_f_mem(ulong top) { @@ -1054,4 +1056,3 @@ ulong board_init_f_mem(ulong top)

    return top;

}

-#endif /* !CONFIG_X86 */

Reviewed-by: Bin Meng bmeng.cn@gmail.com