ppc4xx: Add Sequoia RAM-booting target

This patch adds another build target for the AMCC Sequoia PPC440EPx
eval board. This RAM-booting version is targeted for boards without
NOR FLASH (NAND booting) which need a possibility to initially
program their NAND FLASH. Using a JTAG debugger (e.g. BDI2000/3000)
configured to setup the SDRAM, this debugger can load this RAM-
booting image to the target address in SDRAM (in this case 0x1000000)
and start it there. Then U-Boot's standard NAND commands can be
used to program the NAND FLASH (e.g. "nand write ...").

Here the commands to load and start this image from the BDI2000:

440EPX>reset halt
440EPX>load 0x1000000 /tftpboot/sequoia/u-boot.bin
440EPX>go 0x1000000

Please note that this image automatically scans for an already
initialized SDRAM TLB (detected by EPN=0). This TLB will not be
cleared. This TLB doesn't need to be TLB #0, this RAM-booting
version will detect it and preserve it. So booting via BDI2000
will work and booting with a complete different TLB init via
U-Boot works as well.

Signed-off-by: Stefan Roese <sr@denx.de>

4 files changed, 143 insertions, 3 deletions

diff --git a/board/amcc/sequoia/init.S b/board/amcc/sequoia/init.S
index 4452d26cd..3c0e400f9 100644
--- a/board/amcc/sequoia/init.S
+++ b/board/amcc/sequoia/init.S
@@ -43,12 +43,19 @@ tlbtab:
 	/* vxWorks needs this as first entry for the Machine Check interrupt */
 	tlbentry( 0x40000000, SZ_256M, 0, 0, AC_R|AC_W|AC_X|SA_G|SA_I )
 
+	/*
+	 * The RAM-boot version skips the SDRAM TLB (identified by EPN=0). This
+	 * entry is already configured for SDRAM via the JTAG debugger and mustn't
+	 * be re-initialized by this RAM-booting U-Boot version.
+	 */
+#ifndef CONFIG_SYS_RAMBOOT
 	/* TLB-entry for DDR SDRAM (Up to 2GB) */
 #ifdef CONFIG_4xx_DCACHE
 	tlbentry( CONFIG_SYS_SDRAM_BASE, SZ_256M, CONFIG_SYS_SDRAM_BASE, 0, AC_R|AC_W|AC_X|SA_G)
 #else
 	tlbentry( CONFIG_SYS_SDRAM_BASE, SZ_256M, CONFIG_SYS_SDRAM_BASE, 0, AC_R|AC_W|AC_X|SA_G|SA_I )
 #endif
+#endif /* CONFIG_SYS_RAMBOOT */
 
 	/* TLB-entry for EBC */
 	tlbentry( CONFIG_SYS_BCSR_BASE, SZ_256M, CONFIG_SYS_BCSR_BASE, 1, AC_R|AC_W|AC_X|SA_G|SA_I )
diff --git a/board/amcc/sequoia/sdram.c b/board/amcc/sequoia/sdram.c
index 6df4c6d9b..bde471c2e 100644
--- a/board/amcc/sequoia/sdram.c
+++ b/board/amcc/sequoia/sdram.c
@@ -54,7 +54,8 @@ extern void denali_core_search_data_eye(void);
  ************************************************************************/
 phys_size_t initdram (int board_type)
 {
-#if !defined(CONFIG_NAND_U_BOOT) || defined(CONFIG_NAND_SPL)
+#if !(defined(CONFIG_NAND_U_BOOT) || defined(CONFIG_SYS_RAMBOOT)) || \
+    defined(CONFIG_NAND_SPL)
 	ulong speed = get_bus_freq(0);
 
 	mtsdram(DDR0_02, 0x00000000);
diff --git a/board/amcc/sequoia/sequoia.c b/board/amcc/sequoia/sequoia.c
index e824b8fa4..246ad9484 100644
--- a/board/amcc/sequoia/sequoia.c
+++ b/board/amcc/sequoia/sequoia.c
@@ -33,7 +33,9 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#if !defined(CONFIG_SYS_NO_FLASH)
 extern flash_info_t flash_info[CONFIG_SYS_MAX_FLASH_BANKS]; /* info for FLASH chips */
+#endif
 
 extern void __ft_board_setup(void *blob, bd_t *bd);
 ulong flash_get_size(ulong base, int banknum);
@@ -122,16 +124,19 @@ int board_early_init_f(void)
 
 int misc_init_r(void)
 {
+#if !defined(CONFIG_SYS_NO_FLASH)
 	uint pbcr;
 	int size_val = 0;
-	u32 reg;
+#endif
 #ifdef CONFIG_440EPX
 	unsigned long usb2d0cr = 0;
 	unsigned long usb2phy0cr, usb2h0cr = 0;
 	unsigned long sdr0_pfc1;
 	char *act = getenv("usbact");
 #endif
+	u32 reg;
 
+#if !defined(CONFIG_SYS_NO_FLASH)
 	/* Re-do flash sizing to get full correct info */
 
 	/* adjust flash start and offset */
@@ -171,6 +176,7 @@ int misc_init_r(void)
 			    CONFIG_ENV_ADDR_REDUND + 2*CONFIG_ENV_SECT_SIZE - 1,
 			    &flash_info[0]);
 #endif
+#endif /* CONFIG_SYS_NO_FLASH */
 
 	/*
 	 * USB suff...
@@ -515,7 +521,7 @@ int post_hotkeys_pressed(void)
 }
 #endif /* CONFIG_POST */
 
-#if defined(CONFIG_NAND_U_BOOT)
+#if defined(CONFIG_NAND_U_BOOT) || defined(CONFIG_SYS_RAMBOOT)
 /*
  * On NAND-booting sequoia, we need to patch the chips select numbers
  * in the dtb (CS0 - NAND, CS3 - NOR)
diff --git a/board/amcc/sequoia/u-boot-ram.lds b/board/amcc/sequoia/u-boot-ram.lds
new file mode 100644
index 000000000..9393b6517
--- /dev/null
+++ b/board/amcc/sequoia/u-boot-ram.lds
@@ -0,0 +1,126 @@
+/*
+ * (C) Copyright 2009
+ * Stefan Roese, DENX Software Engineering, sr@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program 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 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+OUTPUT_ARCH(powerpc)
+SECTIONS
+{
+  /* Read-only sections, merged into text segment: */
+  . = + SIZEOF_HEADERS;
+  .interp : { *(.interp) }
+  .hash          : { *(.hash)		}
+  .dynsym        : { *(.dynsym)		}
+  .dynstr        : { *(.dynstr)		}
+  .rel.text      : { *(.rel.text)		}
+  .rela.text     : { *(.rela.text)	}
+  .rel.data      : { *(.rel.data)		}
+  .rela.data     : { *(.rela.data)	}
+  .rel.rodata    : { *(.rel.rodata)	}
+  .rela.rodata   : { *(.rela.rodata)	}
+  .rel.got       : { *(.rel.got)		}
+  .rela.got      : { *(.rela.got)		}
+  .rel.ctors     : { *(.rel.ctors)	}
+  .rela.ctors    : { *(.rela.ctors)	}
+  .rel.dtors     : { *(.rel.dtors)	}
+  .rela.dtors    : { *(.rela.dtors)	}
+  .rel.bss       : { *(.rel.bss)		}
+  .rela.bss      : { *(.rela.bss)		}
+  .rel.plt       : { *(.rel.plt)		}
+  .rela.plt      : { *(.rela.plt)		}
+  .init          : { *(.init)	}
+  .plt : { *(.plt) }
+  .text      :
+  {
+    cpu/ppc4xx/start.o	(.text)
+
+    *(.text)
+    *(.fixup)
+    *(.got1)
+  }
+  _etext = .;
+  PROVIDE (etext = .);
+  .rodata    :
+  {
+    *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*)))
+  }
+  .fini      : { *(.fini)    } =0
+  .ctors     : { *(.ctors)   }
+  .dtors     : { *(.dtors)   }
+
+  /* Read-write section, merged into data segment: */
+  . = (. + 0x00FF) & 0xFFFFFF00;
+  _erotext = .;
+  PROVIDE (erotext = .);
+  .reloc   :
+  {
+    *(.got)
+    _GOT2_TABLE_ = .;
+    *(.got2)
+    _FIXUP_TABLE_ = .;
+    *(.fixup)
+  }
+  __got2_entries = (_FIXUP_TABLE_ - _GOT2_TABLE_) >>2;
+  __fixup_entries = (. - _FIXUP_TABLE_)>>2;
+
+  .data    :
+  {
+    *(.data)
+    *(.data1)
+    *(.sdata)
+    *(.sdata2)
+    *(.dynamic)
+    CONSTRUCTORS
+  }
+  _edata  =  .;
+  PROVIDE (edata = .);
+
+  . = .;
+  __u_boot_cmd_start = .;
+  .u_boot_cmd : { *(.u_boot_cmd) }
+  __u_boot_cmd_end = .;
+
+
+  . = .;
+  __start___ex_table = .;
+  __ex_table : { *(__ex_table) }
+  __stop___ex_table = .;
+
+  . = ALIGN(256);
+  __init_begin = .;
+  .text.init : { *(.text.init) }
+  .data.init : { *(.data.init) }
+  . = ALIGN(256);
+  __init_end = .;
+
+  __bss_start = .;
+  .bss (NOLOAD)       :
+  {
+   *(.sbss) *(.scommon)
+   *(.dynbss)
+   *(.bss)
+   *(COMMON)
+   . = ALIGN(4);
+  }
+
+  _end = . ;
+  PROVIDE (end = .);
+}