cpu/microwatt: add initial software support

diff --git a/litex/soc/cores/cpu/microwatt/core.py b/litex/soc/cores/cpu/microwatt/core.py
index 9fd41ea0079781da1ea157774310933b6223eb08..22ce12d960d9bebb417b99c912ffea9213079211 100644 (file)
--- a/litex/soc/cores/cpu/microwatt/core.py
+++ b/litex/soc/cores/cpu/microwatt/core.py
@@ -18,7 +18,7 @@ class Microwatt(CPU):
     data_width           = 64
     endianness           = "little"
     gcc_triple           = ("powerpc64le-linux")
-    linker_output_format = "elf64-powerpc64le"
+    linker_output_format = "elf64-powerpcle"
     io_regions           = {0xc0000000: 0x10000000} # origin, length
 
     @property

diff --git a/litex/soc/integration/soc_core.py b/litex/soc/integration/soc_core.py
index 63c1f8ef041a9ff47c2fe7bf2c5ea5db641d938e..6bafe6f1f28efb9d3f67519706c667945c64c828 100644 (file)
--- a/litex/soc/integration/soc_core.py
+++ b/litex/soc/integration/soc_core.py
@@ -170,6 +170,8 @@ class SoCCore(Module):
                 raise ValueError("Unsupported CPU type: {}".format(cpu_type))
             # Declare the CPU
             self.submodules.cpu = cpu.CPUS[cpu_type](platform, self.cpu_variant)
+            if cpu_type == "microwatt":
+                self.add_constant("UART_POLLING", None)
 
             # Update Memory Map (if defined by CPU)
             self.soc_mem_map.update(self.cpu.mem_map)

diff --git a/litex/soc/software/bios/boot-helper-microwatt.S b/litex/soc/software/bios/boot-helper-microwatt.S
new file mode 100644 (file)
index 0000000..8dc226d
--- /dev/null
+++ b/litex/soc/software/bios/boot-helper-microwatt.S
@@ -0,0 +1,4 @@
+.section    .text, "ax", @progbits
+.global     boot_helper
+boot_helper:
+       nop # FIXME

diff --git a/litex/soc/software/bios/isr.c b/litex/soc/software/bios/isr.c
index aa47caccd147449e2b39708f8b1ec45bf542d612..68944072d1ee68002a6ef3e15857d024f8c70bfe 100644 (file)
--- a/litex/soc/software/bios/isr.c
+++ b/litex/soc/software/bios/isr.c
@@ -56,7 +56,9 @@ void isr(void)
 
        irqs = irq_pending() & irq_getmask();
 
+#ifndef UART_POLLING
        if(irqs & (1 << UART_INTERRUPT))
                uart_isr();
+#endif
 }
 #endif

diff --git a/litex/soc/software/bios/sdram.c b/litex/soc/software/bios/sdram.c
index 652d9098fef0d7ee86cd7cc1c84c6f7e34ff4339..712138d23fe3255d8f1ee86829ff49d9c596e466 100644 (file)
--- a/litex/soc/software/bios/sdram.c
+++ b/litex/soc/software/bios/sdram.c
@@ -46,6 +46,8 @@ __attribute__((unused)) static void cdelay(int i)
                __asm__ volatile("nop");
 #elif defined (__powerpc__)
                __asm__ volatile("nop");
+#elif defined (__microwatt__)
+               __asm__ volatile("nop");
 #else
 #error Unsupported architecture
 #endif

diff --git a/litex/soc/software/include/base/irq.h b/litex/soc/software/include/base/irq.h
index 4bf6786c4569af6209a338a5a3558fd7eda5f423..a9d1fecbe3238c4eeeb0f89eaad623e07c143b31 100644 (file)
--- a/litex/soc/software/include/base/irq.h
+++ b/litex/soc/software/include/base/irq.h
@@ -56,6 +56,8 @@ static inline unsigned int irq_getie(void)
        return (csrr(mstatus) & CSR_MSTATUS_MIE) != 0;
 #elif defined (__rocket__)
        return (csrr(mstatus) & CSR_MSTATUS_MIE) != 0;
+#elif defined (__microwatt__)
+       return 0; // FIXME
 #else
 #error Unsupported architecture
 #endif
@@ -81,6 +83,8 @@ static inline void irq_setie(unsigned int ie)
        if(ie) csrs(mstatus,CSR_MSTATUS_MIE); else csrc(mstatus,CSR_MSTATUS_MIE);
 #elif defined (__rocket__)
        if(ie) csrs(mstatus,CSR_MSTATUS_MIE); else csrc(mstatus,CSR_MSTATUS_MIE);
+#elif defined (__microwatt__)
+       // FIXME
 #else
 #error Unsupported architecture
 #endif
@@ -108,6 +112,8 @@ static inline unsigned int irq_getmask(void)
        return mask;
 #elif defined (__rocket__)
        return csr_readl(PLIC_ENABLED) >> 1;
+#elif defined (__microwatt__)
+       return 0; // FIXME
 #else
 #error Unsupported architecture
 #endif
@@ -129,6 +135,8 @@ static inline void irq_setmask(unsigned int mask)
        asm volatile ("csrw %0, %1" :: "i"(CSR_IRQ_MASK), "r"(mask));
 #elif defined (__rocket__)
        csr_writel(mask << 1, PLIC_ENABLED);
+#elif defined (__microwatt__)
+       // FIXME
 #else
 #error Unsupported architecture
 #endif
@@ -154,6 +162,8 @@ static inline unsigned int irq_pending(void)
        return pending;
 #elif defined (__rocket__)
        return csr_readl(PLIC_PENDING) >> 1;
+#elif defined (__microwatt__)
+       return 0; // FIXME
 #else
 #error Unsupported architecture
 #endif

diff --git a/litex/soc/software/libbase/crt0-microwatt.S b/litex/soc/software/libbase/crt0-microwatt.S
new file mode 100644 (file)
index 0000000..0dd6f34
--- /dev/null
+++ b/litex/soc/software/libbase/crt0-microwatt.S
@@ -0,0 +1,102 @@
+/* Copyright 2013-2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define STACK_TOP      0xffff4000
+
+#define FIXUP_ENDIAN                                              \
+       tdi   0,0,0x48;   /* Reverse endian of b . + 8          */ \
+       b     191f;       /* Skip trampoline if endian is good  */ \
+       .long 0xa600607d; /* mfmsr r11                          */ \
+       .long 0x01006b69; /* xori r11,r11,1                     */ \
+       .long 0x05009f42; /* bcl 20,31,$+4                      */ \
+       .long 0xa602487d; /* mflr r10                           */ \
+       .long 0x14004a39; /* addi r10,r10,20                    */ \
+       .long 0xa64b5a7d; /* mthsrr0 r10                        */ \
+       .long 0xa64b7b7d; /* mthsrr1 r11                        */ \
+       .long 0x2402004c; /* hrfid                              */ \
+191:
+
+
+/* Load an immediate 64-bit value into a register */
+#define LOAD_IMM64(r, e)                       \
+       lis     r,(e)@highest;                  \
+       ori     r,r,(e)@higher;                 \
+       rldicr  r,r, 32, 31;                    \
+       oris    r,r, (e)@h;                     \
+       ori     r,r, (e)@l;
+
+       .section ".head","ax"
+
+       . = 0
+.global _start
+_start:
+       FIXUP_ENDIAN
+
+       /* setup stack */
+       LOAD_IMM64(%r1, STACK_TOP - 0x100)
+       LOAD_IMM64(%r12, main)
+       mtctr   %r12,
+       bctrl
+       ba      0
+
+       /* XXX: litedram init should not take exceptions, maybe we could get
+        *      rid of these to save space, along with a core tweak to suppress
+        *      exceptions in case they happen (just terminate ?)
+        */
+
+#define EXCEPTION(nr)          \
+       .=  nr;      \
+       b       .
+
+       /* More exception stubs */
+       EXCEPTION(0x100)
+       EXCEPTION(0x200)
+       EXCEPTION(0x300)
+       EXCEPTION(0x380)
+       EXCEPTION(0x400)
+       EXCEPTION(0x480)
+       EXCEPTION(0x500)
+       EXCEPTION(0x600)
+       EXCEPTION(0x700)
+       EXCEPTION(0x800)
+       EXCEPTION(0x900)
+       EXCEPTION(0x980)
+       EXCEPTION(0xa00)
+       EXCEPTION(0xb00)
+       EXCEPTION(0xc00)
+       EXCEPTION(0xd00)
+       EXCEPTION(0xe00)
+       EXCEPTION(0xe20)
+       EXCEPTION(0xe40)
+       EXCEPTION(0xe60)
+       EXCEPTION(0xe80)
+       EXCEPTION(0xf00)
+       EXCEPTION(0xf20)
+       EXCEPTION(0xf40)
+       EXCEPTION(0xf60)
+       EXCEPTION(0xf80)
+#if 0
+       EXCEPTION(0x1000)
+       EXCEPTION(0x1100)
+       EXCEPTION(0x1200)
+       EXCEPTION(0x1300)
+       EXCEPTION(0x1400)
+       EXCEPTION(0x1500)
+       EXCEPTION(0x1600)
+#endif
+
+       .text
+

diff --git a/litex/soc/software/libbase/system.c b/litex/soc/software/libbase/system.c
index bb15aad06e70e188018dff30a0310a5c49944d6a..6e7bfafdfdea50fa5714573eea140e1ad82c4c0a 100644 (file)
--- a/litex/soc/software/libbase/system.c
+++ b/litex/soc/software/libbase/system.c
@@ -56,6 +56,9 @@ void flush_cpu_icache(void)
 #elif defined (__rocket__)
        /* FIXME: do something useful here! */
        asm volatile("nop");
+#elif defined (__microwatt__)
+       /* FIXME: do something useful here! */
+       asm volatile("nop");
 #else
 #error Unsupported architecture
 #endif
@@ -101,6 +104,9 @@ void flush_cpu_dcache(void)
 #elif defined (__rocket__)
        /* FIXME: do something useful here! */
        asm volatile("nop");
+#elif defined (__microwatt__)
+       /* FIXME: do something useful here! */
+       asm volatile("nop");
 #else
 #error Unsupported architecture
 #endif