wbinvd
/* Tell 32-bit code it is being entered from an in-RAM copy */
- movw $GD_FLG_WARM_BOOT, %bx
+ movl $GD_FLG_WARM_BOOT, %ebx
+
+ /*
+ * Zero the BIST (Built-In Self Test) value since we don't have it.
+ * It must be 0 or the previous loader would have reported an error.
+ */
+ movl $0, %ebp
+
jmp 1f
+
+ /* Add a way for tools to discover the _start entry point */
+ .align 4
+ .long 0x12345678
_start:
/*
* This is the 32-bit cold-reset entry point, coming from start16.
- * Set %bx to 0 to indicate this.
+ * Set %ebx to GD_FLG_COLD_BOOT to indicate this.
*/
- movw $GD_FLG_COLD_BOOT, %bx
-1:
+ movl $GD_FLG_COLD_BOOT, %ebx
+
/* Save BIST */
movl %eax, %ebp
+1:
+
+ /* Save table pointer */
+ movl %ecx, %esi
/* Load the segement registers to match the GDT loaded in start16.S */
movl $(X86_GDT_ENTRY_32BIT_DS * X86_GDT_ENTRY_SIZE), %eax
andl $0xfffffff0, %esp
post_code(POST_START_STACK)
+ /*
+ * 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
+ */
+
/* Zero the global data since it won't happen later */
xorl %eax, %eax
movl $GENERATED_GBL_DATA_SIZE, %ecx
movl %esi, (%edx)
skip_hob:
+#else
+ /* Store table pointer */
+ movl %esp, %edx
+ addl $GD_TABLE, %edx
+ movl %esi, (%edx)
#endif
+
/* Setup first parameter to setup_gdt, pointer to global_data */
movl %esp, %eax