Refactor arm-uboot code to make it genereic.

arm-coreboot startup code can be very similar to arm-uboot but current code has
U-Boot specific references. So split U-Boot part from generic part.

grub-core/Makefile.core.def

@@ -105,7 +105,7 @@ kernel = {
   mips_startup = kern/mips/startup.S;
   sparc64_ieee1275_startup = kern/sparc64/ieee1275/crt0.S;
   powerpc_ieee1275_startup = kern/powerpc/ieee1275/startup.S;
-  arm_uboot_startup = kern/arm/uboot/startup.S;
+  arm_uboot_startup = kern/arm/startup.S;
   arm_efi_startup = kern/arm/efi/startup.S;
   arm64_efi_startup = kern/arm64/efi/startup.S;
 
@@ -149,6 +149,8 @@ kernel = {
   uboot = kern/uboot/init.c;
   uboot = kern/uboot/hw.c;
   uboot = term/uboot/console.c;
+  arm_uboot = kern/arm/uboot/init.c;
+  arm_uboot = kern/arm/uboot/uboot.S;
 
   terminfoinkernel = term/terminfo.c;
   terminfoinkernel = term/tparm.c;

grub-core/kern/arm/startup.S

@@ -86,7 +86,7 @@ FUNCTION(codestart)
 	@ Stack pointer used as start address for signature probing
 	mov	r12, sp
 	adr	sp, entry_state
-	push	{r1-r12,lr}	@ store U-Boot context (sp in r12)
+	push	{r0-r12,lr}	@ store U-Boot context (sp in r12)
 
 	adr     r1, _start
 	ldr	r0, bss_start_ptr		@ src
@@ -153,69 +153,21 @@ reloc_done:
 	
 	b	EXT_C(grub_main)
 
-	/*
-	 * uboot_syscall():
-	 *   This function is effectively a veneer, so it cannot
-	 *   modify the stack or corrupt any registers other than
-	 *   r12 (ip). Furthermore it needs to restore r8 for
-	 *   U-Boot (Global Data Pointer) and preserve it for Grub.
-	 */
-FUNCTION(grub_uboot_syscall)
-	str     r8, transition_space
-	str     lr, transition_space + 4
-	str     r9, transition_space + 8
-
-	ldr	r8, gd_backup
-	ldr	r9, gd_backup + 4
-
-	bl	do_syscall
-
-	ldr     r8, transition_space
-	ldr     lr, transition_space + 4
-	ldr     r9, transition_space + 8
-
-	bx	lr
-do_syscall:
-
-	ldr	ip, grub_uboot_syscall_ptr
-	bx	ip
-	
-FUNCTION(grub_uboot_return)
-	adr	sp, entry_state_end
-	pop	{r4-r12, lr}
-	mov	sp, r12
-	bx	lr
-
-	
 	.align	3
-@ U-boot context stack space
+@ U-boot/coreboot context stack space
-entry_state_end:
+VARIABLE(grub_arm_saved_registers)
-VARIABLE(grub_uboot_machine_type)
+	.long	0	@ r0
 	.long	0	@ r1
-VARIABLE(grub_uboot_boot_data)
 	.long	0	@ r2
 	.long	0	@ r3
 	.long	0	@ r4
 	.long	0	@ r5
 	.long	0	@ r6
 	.long	0	@ r7
-gd_backup:	
+	.long	0	@ r8
-	.long	0	@ r8 - U-Boot global data pointer up to 2013-09-21
+	.long	0	@ r9
-	.long	0	@ r9 - U-Boot global data pointer 2013-09-21 onwards
 	.long	0	@ r10
 	.long	0	@ r11
-VARIABLE(grub_uboot_search_hint)@ U-Boot stack pointer - 
+	.long	0	@ sp
-	.long	0	@ also API signature address hint.
 	.long	0	@ lr
-entry_state:		@ backup for U-Boot context
+entry_state:
-
-@ GRUB context stack space
-transition_space:	
-	.long	0	@ r8
-	.long	0	@ lr
-	.long	0	@ r9
-
-VARIABLE(grub_uboot_syscall_ptr)
-	.long	0	@
-
-	END

grub-core/kern/arm/uboot/init.c

@@ -0,0 +1,70 @@
+/* init.c - generic U-Boot initialization and finalization */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2016  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/uboot/uboot.h>
+#include <grub/arm/startup.h>
+#include <grub/uboot/api_public.h>
+
+extern int (*grub_uboot_syscall_ptr) (int, int *, ...);
+
+grub_uint32_t
+grub_uboot_get_machine_type (void)
+{
+  return grub_arm_saved_registers.r[1];
+}
+
+grub_addr_t
+grub_uboot_get_boot_data (void)
+{
+  return grub_arm_saved_registers.r[2];
+}
+
+int
+grub_uboot_api_init (void)
+{
+  struct api_signature *start, *end;
+  struct api_signature *p;
+  grub_addr_t grub_uboot_search_hint = grub_arm_saved_registers.sp;
+  if (grub_uboot_search_hint)
+    {
+      /* Extended search range to work around Trim Slice U-Boot issue */
+      start = (struct api_signature *) ((grub_uboot_search_hint & ~0x000fffff)
+					- 0x00500000);
+      end =
+	(struct api_signature *) ((grub_addr_t) start + UBOOT_API_SEARCH_LEN -
+				  API_SIG_MAGLEN + 0x00500000);
+    }
+  else
+    {
+      start = 0;
+      end = (struct api_signature *) (256 * 1024 * 1024);
+    }
+
+  /* Structure alignment is (at least) 8 bytes */
+  for (p = start; p < end; p = (void *) ((grub_addr_t) p + 8))
+    {
+      if (grub_memcmp (&(p->magic), API_SIG_MAGIC, API_SIG_MAGLEN) == 0)
+	{
+	  grub_uboot_syscall_ptr = p->syscall;
+	  return p->version;
+	}
+    }
+
+  return 0;
+}

grub-core/kern/arm/uboot/uboot.S

@@ -0,0 +1,73 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2013  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/offsets.h>
+#include <grub/symbol.h>
+#include <grub/machine/kernel.h>
+
+	/*
+	 * uboot_syscall():
+	 *   This function is effectively a veneer, so it cannot
+	 *   modify the stack or corrupt any registers other than
+	 *   r12 (ip). Furthermore it needs to restore r8 for
+	 *   U-Boot (Global Data Pointer) and preserve it for Grub.
+	 */
+FUNCTION(grub_uboot_syscall)
+	str     r8, transition_space
+	str     lr, transition_space + 4
+	str     r9, transition_space + 8
+
+	ldr	ip, saved_registers_ptr
+	ldr	r8, [ip, #4 * 8]
+	ldr	r9, [ip, #4 * 9]
+
+	bl	do_syscall
+
+	ldr     r8, transition_space
+	ldr     lr, transition_space + 4
+	ldr     r9, transition_space + 8
+
+	bx	lr
+do_syscall:
+
+	ldr	ip, grub_uboot_syscall_ptr
+	bx	ip
+	
+FUNCTION(grub_uboot_return)
+	ldr	ip, saved_registers_ptr
+	ldr	sp, [ip, #4 * 4]
+	pop	{r4-r12, lr}
+	mov	sp, r12
+	bx	lr
+
+	
+	.align	3
+
+@ GRUB context stack space
+transition_space:	
+	.long	0	@ r8
+	.long	0	@ lr
+	.long	0	@ r9
+
+saved_registers_ptr:
+	.long EXT_C(grub_arm_saved_registers)
+
+VARIABLE(grub_uboot_syscall_ptr)
+	.long	0	@
+
+	END

grub-core/kern/uboot/init.c

@@ -36,30 +36,14 @@
 extern char __bss_start[];
 extern char _end[];
 extern grub_size_t grub_total_module_size;
-extern int (*grub_uboot_syscall_ptr) (int, int *, ...);
 static unsigned long timer_start;
 
-extern grub_uint32_t grub_uboot_machine_type;
-extern grub_addr_t grub_uboot_boot_data;
-
 void
 grub_exit (void)
 {
   grub_uboot_return (0);
 }
 
-grub_uint32_t
-grub_uboot_get_machine_type (void)
-{
-  return grub_uboot_machine_type;
-}
-
-grub_addr_t
-grub_uboot_get_boot_data (void)
-{
-  return grub_uboot_boot_data;
-}
-
 static grub_uint64_t
 uboot_timer_ms (void)
 {

grub-core/kern/uboot/uboot.c

@@ -39,48 +39,13 @@
  * returns:	0 if the call not found, 1 if serviced
  */
 
-extern int (*grub_uboot_syscall_ptr) (int, int *, ...);
 extern int grub_uboot_syscall (int, int *, ...);
-extern grub_addr_t grub_uboot_search_hint;
 
 static struct sys_info uboot_sys_info;
 static struct mem_region uboot_mem_info[5];
 static struct device_info * devices;
 static int num_devices;
 
-int
-grub_uboot_api_init (void)
-{
-  struct api_signature *start, *end;
-  struct api_signature *p;
-
-  if (grub_uboot_search_hint)
-    {
-      /* Extended search range to work around Trim Slice U-Boot issue */
-      start = (struct api_signature *) ((grub_uboot_search_hint & ~0x000fffff)
-					- 0x00500000);
-      end =
-	(struct api_signature *) ((grub_addr_t) start + UBOOT_API_SEARCH_LEN -
-				  API_SIG_MAGLEN + 0x00500000);
-    }
-  else
-    {
-      start = 0;
-      end = (struct api_signature *) (256 * 1024 * 1024);
-    }
-
-  /* Structure alignment is (at least) 8 bytes */
-  for (p = start; p < end; p = (void *) ((grub_addr_t) p + 8))
-    {
-      if (grub_memcmp (&(p->magic), API_SIG_MAGIC, API_SIG_MAGLEN) == 0)
-	{
-	  grub_uboot_syscall_ptr = p->syscall;
-	  return p->version;
-	}
-    }
-
-  return 0;
-}
 
 /*
  * All functions below are wrappers around the grub_uboot_syscall() function

include/grub/arm/startup.h

@@ -0,0 +1,16 @@
+#ifndef GRUB_STARTUP_CPU_HEADER
+#define GRUB_STARTUP_CPU_HEADER
+
+struct grub_arm_startup_registers
+{
+  /* registers 0-11 */
+  /* for U-boot r[1] is machine type */
+  /* for U-boot r[2] is boot data */
+  grub_uint32_t r[12];
+  grub_uint32_t sp;
+  grub_uint32_t lr;
+};
+
+extern struct grub_arm_startup_registers grub_arm_saved_registers;
+
+#endif