[Qemu-devel] [PATCH v1 11/23] tests/tcg/alpha: add system boot.S

[Alex Bennée]

From: Richard Henderson <address@hidden>

This provides the bootstrap and low level helper functions for an
alpha kernel.  We use direct access to the DP264 serial port for
test output, and hard machine halt to exit the emulation.

Signed-off-by: Richard Henderson <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Alex Bennée <address@hidden>
---
 MAINTAINERS                             |   1 +
 tests/tcg/alpha/Makefile.softmmu-target |  32 ++
 tests/tcg/alpha/system/boot.S           | 511 ++++++++++++++++++++++++
 tests/tcg/alpha/system/kernel.ld        |  30 ++
 4 files changed, 574 insertions(+)
 create mode 100644 tests/tcg/alpha/Makefile.softmmu-target
 create mode 100644 tests/tcg/alpha/system/boot.S
 create mode 100644 tests/tcg/alpha/system/kernel.ld

diff --git a/MAINTAINERS b/MAINTAINERS
index 66ddbda9c95..eb3058f8e76 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -470,6 +470,7 @@ M: Richard Henderson <address@hidden>
 S: Maintained
 F: hw/alpha/
 F: hw/isa/smc37c669-superio.c
+F: tests/tcg/alpha/system/
 
 ARM Machines
 ------------
diff --git a/tests/tcg/alpha/Makefile.softmmu-target 
b/tests/tcg/alpha/Makefile.softmmu-target
new file mode 100644
index 00000000000..9f4b199258f
--- /dev/null
+++ b/tests/tcg/alpha/Makefile.softmmu-target
@@ -0,0 +1,32 @@
+#
+# Alpha system tests
+#
+
+ALPHA_SYSTEM_SRC=$(SRC_PATH)/tests/tcg/alpha/system
+VPATH+=$(ALPHA_SYSTEM_SRC)
+
+# These objects provide the basic boot code and helper functions for all tests
+CRT_OBJS=boot.o
+
+ALPHA_TEST_SRCS=$(wildcard $(ALPHA_SYSTEM_SRC)/*.c)
+ALPHA_TESTS = $(patsubst $(ALPHA_SYSTEM_SRC)/%.c, %, $(ALPHA_TEST_SRCS))
+
+CRT_PATH=$(ALPHA_SYSTEM_SRC)
+LINK_SCRIPT=$(ALPHA_SYSTEM_SRC)/kernel.ld
+LDFLAGS=-Wl,-T$(LINK_SCRIPT)
+TESTS+=$(ALPHA_TESTS) $(MULTIARCH_TESTS)
+CFLAGS+=-nostdlib -g -O1 -mcpu=ev6 $(MINILIB_INC)
+LDFLAGS+=-static -nostdlib $(CRT_OBJS) $(MINILIB_OBJS) -lgcc
+
+# building head blobs
+.PRECIOUS: $(CRT_OBJS)
+
+%.o: $(CRT_PATH)/%.S
+       $(CC) $(CFLAGS) -x assembler-with-cpp -c $< -o $@
+
+# Build and link the tests
+%: %.c $(LINK_SCRIPT) $(CRT_OBJS) $(MINILIB_OBJS)
+       $(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)
+
+# Running
+QEMU_OPTS+=-serial chardev:output -kernel
diff --git a/tests/tcg/alpha/system/boot.S b/tests/tcg/alpha/system/boot.S
new file mode 100644
index 00000000000..9791b1ef7c8
--- /dev/null
+++ b/tests/tcg/alpha/system/boot.S
@@ -0,0 +1,511 @@
+/*
+ * Minimal Alpha system boot code.
+ *
+ * Copyright Linaro Ltd 2019
+ */
+
+       .set    noat
+       .set    nomacro
+       .arch   ev6
+       .text
+
+.macro load_pci_io reg
+       /* For typhoon, this is
+        *   0xfffffc0000000000  -- kseg identity map
+        * +      0x10000000000  -- typhoon pio base
+        * +        0x1fc000000  -- typhoon pchip0 pci base
+        * = 0xfffffd01fc000000
+        */
+       ldah    \reg, -3                /* ff..fd0000 */
+       lda     \reg, 0x1fc(\reg)       /* ff..fd01fc */
+       sll     \reg, 24, \reg
+.endm
+
+#define com1Rbr 0x3f8
+#define com1Thr 0x3f8
+#define com1Ier 0x3f9
+#define com1Iir 0x3fa
+#define com1Lcr 0x3fb
+#define com1Mcr 0x3fc
+#define com1Lsr 0x3fd
+#define com1Msr 0x3fe
+#define com1Scr 0x3ff
+#define com1Dll 0x3f8
+#define com1Dlm 0x3f9
+
+#define PAL_halt    0
+#define PAL_wrent  52
+#define PAL_wrkgp  55
+
+       .text
+       .p2align 4
+       .globl  _start
+       .ent    _start
+_start:
+       br      $gp, .+4
+       ldah    $gp, 0($gp)             !gpdisp!1
+       lda     $gp, 0($gp)             !gpdisp!1
+
+       ldah    $sp, $stack_end($gp)    !gprelhigh
+       lda     $sp, $stack_end($sp)    !gprellow
+
+       /* Install kernel gp for exception handlers.  */
+       mov     $gp, $16
+       call_pal PAL_wrkgp
+
+       /* Install exception handlers.  */
+       ldah    $16, entInt($gp)        !gprelhigh
+       lda     $16, entInt($16)        !gprellow
+       lda     $17, 0
+       call_pal PAL_wrent
+
+       ldah    $16, entArith($gp)      !gprelhigh
+       lda     $16, entArith($16)      !gprellow
+       lda     $17, 1
+       call_pal PAL_wrent
+
+       ldah    $16, entMM($gp)         !gprelhigh
+       lda     $16, entMM($16)         !gprellow
+       lda     $17, 2
+       call_pal PAL_wrent
+
+       ldah    $16, entIF($gp)         !gprelhigh
+       lda     $16, entIF($16)         !gprellow
+       lda     $17, 3
+       call_pal PAL_wrent
+
+       ldah    $16, entUna($gp)        !gprelhigh
+       lda     $16, entUna($16)        !gprellow
+       lda     $17, 4
+       call_pal PAL_wrent
+
+       ldah    $16, entSys($gp)        !gprelhigh
+       lda     $16, entSys($16)        !gprellow
+       lda     $17, 5
+       call_pal PAL_wrent
+
+       /*
+        * Initialize COM1.
+        */
+       load_pci_io $1
+       lda     $2, 0x87                /* outb(0x87, com1Lcr); */
+       stb     $2, com1Lcr($1)
+       stb     $31, com1Dlm($1)        /* outb(0, com1Dlm); */
+       lda     $2, 3                   /* baudconst 3 => 56000 */
+       stb     $2, com1Dll($1)         /* outb(baudconst, com1Dll); */
+       lda     $2, 0x07
+       stb     $2, com1Lcr($1)         /* outb(0x07, com1Lcr) */
+       lda     $2, 0x0f
+       stb     $2, com1Mcr($1)         /* outb(0x0f, com1Mcr) */
+
+       bsr     $26, main               !samegp
+
+       /* fall through to _exit */
+       .end    _start
+
+       .globl  _exit
+       .ent    _exit
+_exit:
+       .frame  $sp, 0, $26, 0
+       .prologue 0
+
+       /* We cannot return an error code.  */
+       call_pal PAL_halt
+       .end    _exit
+
+/*
+ * We have received an exception that we don't handle.  Log and exit.
+ */
+       .ent    log_exit
+log_exit:
+entInt:
+entArith:
+entMM:
+entIF:
+entUna:
+entSys:
+       ldah    $16, $errormsg($gp)     !gprelhigh
+       lda     $16, $errormsg($16)     !gprellow
+       bsr     $26, __sys_outs         !samegp
+       bsr     $26, _exit              !samegp
+       .end    log_exit
+
+       .section .rodata
+$errormsg:
+       .string "Terminated by exception.\n"
+       .previous
+
+       /*
+        * Helper Functions
+        */
+
+       /* Output a single character to serial port */
+       .global __sys_outc
+       .ent    __sys_outc
+__sys_outc:
+       .frame  $sp, 0, $26, 0
+       .prologue 0
+
+       load_pci_io $1
+
+       /* 
+        * while ((inb(com1Lsr) & 0x20) == 0)
+        *       continue;
+        */
+1:     ldbu    $0, com1Lsr($1)
+       and     $0, 0x20, $0
+       beq     $0, 1b
+
+       /* outb(c, com1Thr); */
+       stb     $16, com1Thr($1)
+       ret
+       .end    __sys_outc
+
+       /* Output a nul-terminated string to serial port */
+       .global __sys_outs
+       .ent    __sys_outs
+__sys_outs:
+       .frame  $sp, 0, $26, 0
+       .prologue 0
+
+       load_pci_io $1
+
+       ldbu    $2, 0($16)
+       beq     $2, 9f
+
+       /* 
+        * while ((inb(com1Lsr) & 0x20) == 0)
+        *       continue;
+        */
+1:     ldbu    $0, com1Lsr($1)
+       and     $0, 0x20, $0
+       beq     $0, 1b
+
+       /* outb(c, com1Thr); */
+       stb     $2, com1Thr($1)
+
+       addq    $16, 1, $16
+       ldbu    $2, 0($16)
+       bne     $2, 1b
+
+9:     ret
+       .end    __sys_outs
+
+/*
+ * Division routines that are normally in libc.
+ *
+ * These do not follow the C calling convention.  Arguments are in $24+$25,
+ * the result is in $27.  Register $28 may be clobbered; everything else
+ * must be saved.
+ *
+ * We store the remainder in $28, so that we can share code.
+ *
+ * We do not signal divide by zero.
+ */
+
+/*
+ * Unsigned 64-bit division.
+ */
+
+       .globl  __divqu
+       .ent    __divqu
+__divqu:
+       .frame  $sp, 48, $23
+       subq    $sp, 48, $sp
+       stq     $0, 0($sp)
+       stq     $1, 8($sp)
+       stq     $2, 16($sp)
+       stq     $3, 24($sp)
+       stq     $4, 32($sp)
+       .prologue 0
+
+#define mask     $0
+#define divisor  $1
+#define compare  $2
+#define tmp1     $3
+#define tmp2     $4
+#define quotient $27
+#define modulus  $28
+
+       mov     $24, modulus
+       mov     $25, divisor
+       mov     $31, quotient
+       mov     1, mask
+       beq     $25, 9f
+
+       /* Shift left until divisor >= modulus.  */
+1:     cmpult  divisor, modulus, compare
+       blt     divisor, 2f
+       addq    divisor, divisor, divisor
+       addq    mask, mask, mask
+       bne     compare, 1b
+
+2:     addq    quotient, mask, tmp2
+       srl     mask, 1, mask
+       cmpule  divisor, modulus, compare
+       subq    modulus, divisor, tmp1
+       cmovne  compare, tmp2, quotient
+       srl     divisor, 1, divisor
+       cmovne  compare, tmp1, modulus
+       bne     mask, 2b
+
+9:     ldq     $0, 0($sp)
+       ldq     $1, 8($sp)
+       ldq     $2, 16($sp)
+       ldq     $3, 24($sp)
+       ldq     $4, 32($sp)
+       addq    $sp, 48, $sp
+       ret     $31, ($23), 1
+
+#undef mask
+#undef divisor
+#undef compare
+#undef tmp1
+#undef tmp2
+#undef quotient
+#undef modulus
+
+       .end    __divqu
+
+/*
+ * Unsigned 64-bit remainder.
+ * Note that __divqu above leaves the result in $28.
+ */
+
+       .globl  __remqu
+       .ent    __remqu
+__remqu:
+       .frame  $sp, 16, $23
+       subq    $sp, 16, $sp
+       stq     $23, 0($sp)
+       .prologue 0
+
+       bsr     $23, __divqu
+
+       ldq     $23, 0($sp)
+       mov     $28, $27
+       addq    $sp, 16, $sp
+       ret     $31, ($23), 1
+       .end    __remqu
+
+/*
+ * Signed 64-bit division.
+ */
+
+       .globl  __divqs
+       .ent    __divqs
+__divqs:
+       .prologue 0
+
+       /* Common case: both arguments are positive.  */
+       bis     $24, $25, $28
+       bge     $28, __divqu
+
+       /* At least one argument is negative.  */
+       subq    $sp, 32, $sp
+       stq     $23, 0($sp)
+       stq     $24, 8($sp)
+       stq     $25, 16($sp)
+
+       /* Compute absolute values.  */
+       subq    $31, $24, $28
+       cmovlt  $24, $28, $24
+       subq    $31, $25, $28
+       cmovlt  $25, $28, $25
+
+       bsr     $23, __divqu
+
+       ldq     $24, 8($sp)
+       ldq     $25, 16($sp)
+
+       /* -a / b = a / -b = -(a / b) */
+       subq    $31, $27, $23
+       xor     $24, $25, $28
+       cmovlt  $28, $23, $27
+
+       ldq     $23, 0($sp)
+       addq    $sp, 32, $sp
+       ret     $31, ($23), 1
+       .end    __divqs
+
+/*
+ * Signed 64-bit remainder.
+ */
+
+       .globl  __remqs
+       .ent    __remqs
+__remqs:
+       .prologue 0
+
+       /* Common case: both arguments are positive.  */
+       bis     $24, $25, $28
+       bge     $28, __remqu
+
+       /* At least one argument is negative.  */
+       subq    $sp, 32, $sp
+       stq     $23, 0($sp)
+       stq     $24, 8($sp)
+       stq     $25, 16($sp)
+
+       /* Compute absolute values.  */
+       subq    $31, $24, $28
+       cmovlt  $24, $28, $24
+       subq    $31, $25, $28
+       cmovlt  $25, $28, $25
+
+       bsr     $23, __divqu
+
+       ldq     $23, 0($sp)
+       ldq     $24, 8($sp)
+       ldq     $25, 16($sp)
+
+       /* -a % b = -(a % b); a % -b = a % b.  */
+       subq    $31, $28, $27
+       cmovge  $24, $28, $27
+
+       addq    $sp, 32, $sp
+       ret     $31, ($23), 1
+       .end    __remqs
+
+/*
+ * Unsigned 32-bit division.
+ */
+
+       .globl  __divlu
+       .ent    __divlu
+__divlu:
+       .frame  $sp, 32, $23
+       subq    $sp, 32, $sp
+       stq     $23, 0($sp)
+       stq     $24, 8($sp)
+       stq     $25, 16($sp)
+       .prologue 0
+
+       /* Zero extend and use the 64-bit routine.  */
+       zap     $24, 0xf0, $24
+       zap     $25, 0xf0, $25
+       bsr     $23, __divqu
+
+       addl    $27, 0, $27
+       ldq     $23, 0($sp)
+       ldq     $24, 8($sp)
+       ldq     $25, 16($sp)
+       addq    $sp, 32, $sp
+       ret     $31, ($23), 1
+       .end    __divlu
+
+/*
+ * Unsigned 32-bit remainder.
+ */
+
+       .globl  __remlu
+       .ent    __remlu
+__remlu:
+       .frame  $sp, 32, $23
+       subq    $sp, 32, $sp
+       stq     $23, 0($sp)
+       stq     $24, 8($sp)
+       stq     $25, 16($sp)
+       .prologue 0
+
+       /* Zero extend and use the 64-bit routine.  */
+       zap     $24, 0xf0, $24
+       zap     $25, 0xf0, $25
+       bsr     $23, __divqu
+
+       /* Recall that the remainder is returned in $28.  */
+       addl    $28, 0, $27
+       ldq     $23, 0($sp)
+       ldq     $24, 8($sp)
+       ldq     $25, 16($sp)
+       addq    $sp, 32, $sp
+       ret     $31, ($23), 1
+       .end    __remlu
+
+/*
+ * Signed 32-bit division.
+ */
+
+       .globl  __divls
+       .ent    __divls
+__divls:
+       .frame  $sp, 32, $23
+       subq    $sp, 32, $sp
+       stq     $23, 0($sp)
+       stq     $24, 8($sp)
+       stq     $25, 16($sp)
+       .prologue 0
+
+       /* Sign extend.  */
+       addl    $24, 0, $24
+       addl    $25, 0, $25
+
+       /* Compute absolute values.  */
+       subq    $31, $24, $28
+       cmovlt  $24, $28, $24
+       subq    $31, $25, $28
+       cmovlt  $25, $28, $25
+
+       bsr     $23, __divqu
+
+       ldq     $24, 8($sp)
+       ldq     $25, 16($sp)
+
+       /* Negate the unsigned result, if necessary.  */
+       xor     $24, $25, $28
+       subl    $31, $27, $23
+       addl    $27, 0, $27
+       addl    $28, 0, $28
+       cmovlt  $28, $23, $27
+
+       ldq     $23, 0($sp)
+       addq    $sp, 32, $sp
+       ret     $31, ($23), 1
+       .end    __divls
+
+/*
+ * Signed 32-bit remainder.
+ */
+
+       .globl  __remls
+       .ent    __remls
+__remls:
+       .frame  $sp, 32, $23
+       subq    $sp, 32, $sp
+       stq     $23, 0($sp)
+       stq     $24, 8($sp)
+       stq     $25, 16($sp)
+       .prologue 0
+
+       /* Sign extend.  */
+       addl    $24, 0, $24
+       addl    $25, 0, $25
+
+       /* Compute absolute values.  */
+       subq    $31, $24, $28
+       cmovlt  $24, $28, $24
+       subq    $31, $25, $28
+       cmovlt  $25, $28, $25
+
+       bsr     $23, __divqu
+
+       ldq     $23, 0($sp)
+       ldq     $24, 8($sp)
+       ldq     $25, 16($sp)
+
+       /* Negate the unsigned result, if necessary.  */
+       subl    $31, $28, $27
+       addl    $28, 0, $28
+       cmovge  $24, $28, $27
+
+       addq    $sp, 32, $sp
+       ret     $31, ($23), 1
+       .end    __remls
+
+       .data
+       .p2align 4
+stack:
+       .skip   65536
+$stack_end:
+       .type   stack,@object
+       .size   stack, . - stack
diff --git a/tests/tcg/alpha/system/kernel.ld b/tests/tcg/alpha/system/kernel.ld
new file mode 100644
index 00000000000..d2ac6ecfeb8
--- /dev/null
+++ b/tests/tcg/alpha/system/kernel.ld
@@ -0,0 +1,30 @@
+ENTRY(_start)
+
+SECTIONS
+{
+    /* Linux kernel legacy start address.  */
+    . = 0xfffffc0000310000;
+    _text = .;
+    .text : {
+        *(.text)
+    }
+    .rodata : {
+        *(.rodata)
+    }
+    _etext = .;
+
+    . = ALIGN(8192);
+    _data = .;
+    .got : {
+        *(.got)
+    }
+    .data : {
+       *(.sdata)
+        *(.data)
+    }
+    _edata = .;
+    .bss : {
+        *(.bss)
+    }
+    _end = .;
+}
-- 
2.20.1