summaryrefslogtreecommitdiff
path: root/src/cpu/ppc/mpc74xx/mpc74xx.inc
diff options
context:
space:
mode:
authorGreg Watson <jarrah@users.sourceforge.net>2003-07-24 21:03:45 +0000
committerGreg Watson <jarrah@users.sourceforge.net>2003-07-24 21:03:45 +0000
commitf7dd98995581302666c09c6c437bbe3e61ad6a2c (patch)
tree25f955f6a001acfcde52874d1c8ddb7564ee1645 /src/cpu/ppc/mpc74xx/mpc74xx.inc
parentb794667b75e96370a8d409a6dc9781043170e4f9 (diff)
*** empty log message ***
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@1030 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Diffstat (limited to 'src/cpu/ppc/mpc74xx/mpc74xx.inc')
-rw-r--r--src/cpu/ppc/mpc74xx/mpc74xx.inc190
1 files changed, 190 insertions, 0 deletions
diff --git a/src/cpu/ppc/mpc74xx/mpc74xx.inc b/src/cpu/ppc/mpc74xx/mpc74xx.inc
new file mode 100644
index 0000000000..6d23c3ad7e
--- /dev/null
+++ b/src/cpu/ppc/mpc74xx/mpc74xx.inc
@@ -0,0 +1,190 @@
+/* Copyright 2000 AG Electronics Ltd. */
+/* This code is distributed without warranty under the GPL v2 (see COPYING) */
+
+/*
+ * The aim of this code is to bring the machine from power-on to the point
+ * where we can jump to the the main LinuxBIOS entry point hardwaremain()
+ * which is written in C.
+ *
+ * At power-on, we have no RAM, a memory-mapped I/O space, and we are executing
+ * out of ROM, generally at 0xfff00100.
+ *
+ * Before we jump to harwaremain() we want to do the following:
+ *
+ * - enable L1 I/D caches, otherwise performance will be slow
+ * - set up DBATs for the following regions:
+ * - RAM (generally 0x00000000 - 0x7fffffff)
+ * - ROM (_ROMBASE - _ROMBASE + 16Mb)
+ * - I/O (generally 0xfc000000 - 0xfdffffff)
+ * - the main purpose for setting up the DBATs is so the I/O region
+ * can be marked cache inhibited/write through
+ * - set up IBATs for RAM and ROM
+ *
+ */
+
+#define BSP_IOREGION1 0x80000000
+#define BSP_IOMASK1 BAT_BL_256M | BAT_VALID_SUPERVISOR | BAT_VALID_USER
+#define BSP_IOREGION2 0xFD000000
+#define BSP_IOMASK2 BAT_BL_64M | BAT_VALID_SUPERVISOR | BAT_VALID_USER
+
+ isync
+
+ /*
+ * Disable dcache and MMU, so we're in a known state
+ */
+ li r0, 0
+ sync
+ mtspr HID0, r0
+ sync
+ mtmsr r0
+ isync
+
+ /*
+ * Invalidate D & I BATS
+ */
+ mtibatu 0, r0
+ mtibatu 1, r0
+ mtibatu 2, r0
+ mtibatu 3, r0
+ isync
+ mtdbatu 0, r0
+ mtdbatu 1, r0
+ mtdbatu 2, r0
+ mtdbatu 3, r0
+ isync
+
+ /*
+ * Clear segment registers (LinuxBIOS doesn't use these)
+ */
+ mtsr 0, r0
+ isync
+ mtsr 1, r0
+ isync
+ mtsr 2, r0
+ isync
+ mtsr 3, r0
+ isync
+ mtsr 4, r0
+ isync
+ mtsr 5, r0
+ isync
+ mtsr 6, r0
+ isync
+ mtsr 7, r0
+ isync
+ mtsr 8, r0
+ isync
+ mtsr 9, r0
+ isync
+ mtsr 10, r0
+ isync
+ mtsr 11, r0
+ isync
+ mtsr 12, r0
+ isync
+ mtsr 13, r0
+ isync
+ mtsr 14, r0
+ isync
+ mtsr 15, r0
+ isync
+
+ /*
+ * Initialize northbridge. This has to happen early because it
+ * resets memory. Memory is on at this point, albeit with
+ * pessimistic settings. We reconfigure later using I2C.
+ */
+ bl bsp_init_northbridge
+
+ /*
+ * Set up DBATs
+ *
+ * DBAT0 covers RAM (0 - 256Mb)
+ * DBAT1 covers PCI memory and ROM (0xFC000000 - 0xFFFFFFFF)
+ * DBAT1 covers PCI memory (0x80000000 - 0x8FFFFFFF)
+ */
+ lis r2, 0@ha
+ ori r3, r2, BAT_BL_256M | BAT_VALID_SUPERVISOR | BAT_VALID_USER
+ ori r2, r2, BAT_READ_WRITE
+ mtdbatu 0, r3
+ mtdbatl 0, r2
+ isync
+
+ lis r2, BSP_IOREGION2@ha
+ ori r3, r2, BAT_BL_64M | BAT_VALID_SUPERVISOR | BAT_VALID_USER
+ ori r2, r2, BAT_CACHE_INHIBITED | BAT_GUARDED | BAT_READ_WRITE
+ mtdbatu 1, r3
+ mtdbatl 1, r2
+ isync
+
+ lis r2, BSP_IOREGION1@h
+ ori r3, r2, BSP_IOMASK1
+ ori r2, r2, BAT_CACHE_INHIBITED | BAT_GUARDED | BAT_READ_WRITE
+ mtdbatu 2, r3
+ mtdbatl 2, r2
+ isync
+
+ /*
+ * IBATS
+ *
+ * IBAT0 covers RAM (0 - 256Mb)
+ * IBAT1 covers ROM (_ROMBASE - _ROMBASE+16M)
+ */
+ lis r2, 0@ha
+ ori r3, r2, BAT_BL_256M | BAT_VALID_SUPERVISOR | BAT_VALID_USER
+ ori r2, r2, BAT_READ_WRITE
+ mtibatu 0, r3
+ mtibatl 0, r2
+ isync
+
+ lis r2, _ROMBASE@ha
+ ori r3, r2, BAT_BL_16M | BAT_VALID_SUPERVISOR | BAT_VALID_USER
+ ori r2, r2, BAT_READ_ONLY
+ mtibatu 1, r3
+ mtibatl 1, r2
+ isync
+
+ /*
+ * Invalidate tlb entries
+ */
+ lis r3, 0
+ lis r5, 0x4
+ isync
+tlblp:
+ tlbie r3
+ sync
+ addi r3, r3, 0x1000
+ cmp 0, 0, r3, r5
+ blt tlblp
+
+ sync
+
+ /*
+ * Enable MMU
+ */
+ mfmsr r2
+ ori r2, r2, MSR_DR | MSR_IR
+ isync
+ mtmsr r2
+ isync
+
+ /*
+ * Enable L1 dcache
+ */
+ mfspr r2, HID0
+ ori r2, r2, HID0_DCE | HID0_DCFI
+ sync
+ mtspr HID0, r2
+
+ /*
+ * Enable L1 icache
+ */
+ mfspr r2, HID0
+ ori r2, r2, HID0_ICE | HID0_ICFI
+ isync
+ mtspr HID0, r2
+
+ /*
+ * Must branch to start_payload once CPU initialization is completed
+ */
+ b start_payload