[platform][riscv-virt] added support for QEMU's riscv 'virt' machine

The virt machine is a generic target, much like the arm virt machine. Intended to be simple to use and a good target to run large systems like linux on. At the moment simply support booting and simple uart and timer support.
2019-03-30 21:31:47 -07:00
parent dbe86c89be
commit ae5200595c
18 changed files with 536 additions and 13 deletions
--- a/arch/riscv/linker-onesegment.ld
+++ b/arch/riscv/linker-onesegment.ld
@@ -0,0 +1,107 @@
+OUTPUT_FORMAT("elf32-littleriscv", "elf32-littleriscv", "elf32-littleriscv")
+OUTPUT_ARCH(riscv)
+
+ENTRY(_start)
+SECTIONS
+{
+    . = %KERNEL_BASE% + %KERNEL_LOAD_OFFSET%;
+
+    _start = .;
+
+    /* text/read-only data */
+    /* set the load address to physical MEMBASE */
+    .text : AT(%MEMBASE% + %KERNEL_LOAD_OFFSET%) {
+        KEEP(*(.text.boot))
+        *(.text .text*)
+        *(.gnu.linkonce.t.*)
+    }
+
+    .interp : { *(.interp) }
+    .hash : { *(.hash) }
+    .dynsym : { *(.dynsym) }
+    .dynstr : { *(.dynstr) }
+    .rel.text : { *(.rel.text) *(.rel.gnu.linkonce.t*) }
+    .rela.text : { *(.rela.text) *(.rela.gnu.linkonce.t*) }
+    .rel.data : { *(.rel.data) *(.rel.gnu.linkonce.d*) }
+    .rela.data : { *(.rela.data) *(.rela.gnu.linkonce.d*) }
+    .rel.rodata : { *(.rel.rodata) *(.rel.gnu.linkonce.r*) }
+    .rela.rodata : { *(.rela.rodata) *(.rela.gnu.linkonce.r*) }
+    .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.init : { *(.rel.init) }
+    .rela.init : { *(.rela.init) }
+    .rel.fini : { *(.rel.fini) }
+    .rela.fini : { *(.rela.fini) }
+    .rel.bss : { *(.rel.bss) }
+    .rela.bss : { *(.rela.bss) }
+    .rel.plt : { *(.rel.plt) }
+    .rela.plt : { *(.rela.plt) }
+    .init : { *(.init) }
+    .plt : { *(.plt) }
+
+    .rodata : ALIGN(4) {
+        __rodata_start = .;
+        *(.rodata .rodata.* .gnu.linkonce.r.*)
+        *(.srodata*)
+    }
+
+    /*
+     * extra linker scripts tend to insert sections just after .rodata,
+     * so we want to make sure this symbol comes after anything inserted above,
+     * but not aligned to the next section necessarily.
+     */
+    .dummy_post_rodata : {
+        __rodata_end = .;
+    }
+
+    .data : ALIGN(4) {
+        __data_start_rom = .;
+        /* in one segment binaries, the rom data address is on top of the ram data address */
+        __data_start = .;
+        *(.data .data.* .gnu.linkonce.d.*)
+        PROVIDE( __global_pointer$ = . + (4K / 2) );
+        *(.sdata .sdata.*)
+        __ctor_list = .;
+        KEEP(*(.ctors .init_array))
+        __ctor_end = .;
+        __dtor_list = .;
+        KEEP(*(.dtors .fini_array))
+        __dtor_end = .;
+        *(.got*)
+        *(.dynamic)
+    }
+
+    /*
+     * extra linker scripts tend to insert sections just after .data,
+     * so we want to make sure this symbol comes after anything inserted above,
+     * but not aligned to the next section necessarily.
+     */
+    .dummy_post_data : {
+        __data_end = .;
+    }
+
+    /* uninitialized data (in same segment as writable data) */
+    .bss : ALIGN(4) {
+        __bss_start = .;
+        /* regular bss */
+        *(.bss .bss.*)
+        *(.sbss .sbss.*)
+        *(.gnu.linkonce.b.*)
+
+        . = ALIGN(4);
+        __bss_end = .;
+    }
+
+    _end = .;
+
+    . = %KERNEL_BASE% + %MEMSIZE%;
+    _end_of_ram = .;
+
+    /* Strip unnecessary stuff */
+    /DISCARD/ : { *(.comment .note .eh_frame) }
+}
+