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cpu/microwatt: add initial software support

This commit is contained in:
Florent Kermarrec 2019-12-20 23:32:21 +01:00
parent f883f0c703
commit 0e46913d52
8 changed files with 129 additions and 1 deletions
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2
litex/soc/cores/cpu/microwatt/core.py
View File

@ -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

2
litex/soc/integration/soc_core.py
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@ -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)

4
litex/soc/software/bios/boot-helper-microwatt.S Normal file
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@ -0,0 +1,4 @@
.section .text, "ax", @progbits
.global boot_helper
boot_helper:
nop # FIXME

2
litex/soc/software/bios/isr.c
View File

@ -56,7 +56,9 @@ void isr(void)
irqs = irq_pending() & irq_getmask();
#ifndef UART_POLLING
if(irqs & (1 << UART_INTERRUPT))
uart_isr();
#endif
}
#endif

2
litex/soc/software/bios/sdram.c
View File

@ -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

10
litex/soc/software/include/base/irq.h
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@ -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

102
litex/soc/software/libbase/crt0-microwatt.S Normal file
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@ -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

6
litex/soc/software/libbase/system.c
View File

@ -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