Merge branch 'master' of git://git.denx.de/u-boot-samsung

[u-boot] / arch / x86 / cpu / start.S

diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S
index e94ddc45ddb78475eefa3e306b9f352d1f378755..a5cba1cf2a766680e3e1b8ab6290bee2aa8a0191 100644 (file)
--- a/arch/x86/cpu/start.S
+++ b/arch/x86/cpu/start.S
@@ -18,6 +18,14 @@
 #include <generated/generic-asm-offsets.h>
 #include <generated/asm-offsets.h>
 
+/*
+ * Define this to boot U-Boot from a 32-bit program which sets the GDT
+ * differently. This can be used to boot directly from any stage of coreboot,
+ * for example, bypassing the normal payload-loading feature.
+ * This is only useful for development.
+ */
+#undef LOAD_FROM_32_BIT
+
 .section .text
 .code32
 .globl _start
@@ -68,6 +76,10 @@ _start:
        /* Save table pointer */
        movl    %ecx, %esi
 
+#ifdef LOAD_FROM_32_BIT
+       lgdt    gdt_ptr2
+#endif
+
        /* Load the segement registers to match the GDT loaded in start16.S */
        movl    $(X86_GDT_ENTRY_32BIT_DS * X86_GDT_ENTRY_SIZE), %eax
        movw    %ax, %fs
@@ -115,23 +127,21 @@ car_init_ret:
 #endif
 #else
        /*
-        * When we get here after car_init(), esp points to a temporary stack
-        * and esi holds the HOB list address returned by the FSP.
+        * U-Boot enters here twice. For the first time it comes from
+        * car_init_done() with esp points to a temporary stack and esi
+        * set to zero. For the second time it comes from fsp_init_done()
+        * with esi holding the HOB list address returned by the FSP.
         */
 #endif
        /* Set up global data */
        mov     %esp, %eax
-       call    board_init_f_mem
+       call    board_init_f_alloc_reserve
        mov     %eax, %esp
+       call    board_init_f_init_reserve
 
-       /*
-        * Debug UART is available here although it may not be plumbed out
-        * to pins depending on the board. To use it:
-        *
-        * call  debug_uart_init
-        * mov   $'a', %eax
-        * call  printch
-        */
+#ifdef CONFIG_DEBUG_UART
+       call    debug_uart_init
+#endif
 
        /* Get address of global_data */
        mov     %fs:0, %edx
@@ -141,6 +151,14 @@ car_init_ret:
        jz      skip_hob
        movl    %esi, GD_HOB_LIST(%edx)
 
+       /*
+        * After fsp_init() returns, the stack has already been switched to a
+        * place within system memory as defined by CONFIG_FSP_TEMP_RAM_ADDR.
+        * Enlarge the size of malloc() pool before relocation since we have
+        * plenty of memory now.
+        */
+       subl    $CONFIG_FSP_SYS_MALLOC_F_LEN, %esp
+       movl    %esp, GD_MALLOC_BASE(%edx)
 skip_hob:
 #else
        /* Store table pointer */
@@ -214,3 +232,71 @@ multiboot_header:
        .long   0
        /* entry addr */
        .long   CONFIG_SYS_TEXT_BASE
+
+#ifdef LOAD_FROM_32_BIT
+       /*
+        * The following Global Descriptor Table is just enough to get us into
+        * 'Flat Protected Mode' - It will be discarded as soon as the final
+        * GDT is setup in a safe location in RAM
+        */
+gdt_ptr2:
+       .word   0x1f            /* limit (31 bytes = 4 GDT entries - 1) */
+       .long   gdt_rom2        /* base */
+
+       /* Some CPUs are picky about GDT alignment... */
+       .align  16
+.globl gdt_rom2
+gdt_rom2:
+       /*
+        * The GDT table ...
+        *
+        *       Selector       Type
+        *       0x00           NULL
+        *       0x08           Unused
+        *       0x10           32bit code
+        *       0x18           32bit data/stack
+        */
+       /* The NULL Desciptor - Mandatory */
+       .word   0x0000          /* limit_low */
+       .word   0x0000          /* base_low */
+       .byte   0x00            /* base_middle */
+       .byte   0x00            /* access */
+       .byte   0x00            /* flags + limit_high */
+       .byte   0x00            /* base_high */
+
+       /* Unused Desciptor - (matches Linux) */
+       .word   0x0000          /* limit_low */
+       .word   0x0000          /* base_low */
+       .byte   0x00            /* base_middle */
+       .byte   0x00            /* access */
+       .byte   0x00            /* flags + limit_high */
+       .byte   0x00            /* base_high */
+
+       /*
+        * The Code Segment Descriptor:
+        * - Base   = 0x00000000
+        * - Size   = 4GB
+        * - Access = Present, Ring 0, Exec (Code), Readable
+        * - Flags  = 4kB Granularity, 32-bit
+        */
+       .word   0xffff          /* limit_low */
+       .word   0x0000          /* base_low */
+       .byte   0x00            /* base_middle */
+       .byte   0x9b            /* access */
+       .byte   0xcf            /* flags + limit_high */
+       .byte   0x00            /* base_high */
+
+       /*
+        * The Data Segment Descriptor:
+        * - Base   = 0x00000000
+        * - Size   = 4GB
+        * - Access = Present, Ring 0, Non-Exec (Data), Writable
+        * - Flags  = 4kB Granularity, 32-bit
+        */
+       .word   0xffff          /* limit_low */
+       .word   0x0000          /* base_low */
+       .byte   0x00            /* base_middle */
+       .byte   0x93            /* access */
+       .byte   0xcf            /* flags + limit_high */
+       .byte   0x00            /* base_high */
+#endif