Changeset ae8d7b0 in mainline for boot/arch/riscv64/src/asm.S

Timestamp:

2017-08-21T18:23:39Z (7 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

c58441d

Parents:

fdc29300

Message:

riscv64: update to the latest Privileged Architecture specification (1.10)

File:

• boot/arch/riscv64/src/asm.S (modified) (3 diffs)

boot/arch/riscv64/src/asm.S

@@ -29 +29 @@
 #include <abi/asmtool.h>
 #include <arch/arch.h>
+#include <arch/mm.h>
+
+#define MSTATUS_MPP_MASK        0x00001800
+#define MSTATUS_MPP_USER        0x00000000
+#define MSTATUS_MPP_SUPERVISOR  0x00000800
+#define MSTATUS_MPP_MACHINE     0x00001800
+
+#define MSTATUS_SUM_MASK        0x00040000
+
+#define SATP_PFN_MASK  0x00000fffffffffff
+
+#define SATP_MODE_MASK  0xf000000000000000
+#define SATP_MODE_BARE  0x0000000000000000
+#define SATP_MODE_SV39  0x8000000000000000
+#define SATP_MODE_SV48  0x9000000000000000
 
 .section BOOTSTRAP
@@ -76 +91 @@
 
 FUNCTION_BEGIN(jump_to_kernel)
-        j halt
+        /* Setup SV48 paging for supervisor mode */
+        la t0, ptl_0
+        srli t0, t0, 12
+        
+        li t1, SATP_PFN_MASK
+        and t0, t0, t1
+        
+        li t1, SATP_MODE_SV48
+        or t0, t0, t1
+        
+        csrw sptbr, t0
+        
+        /* Jump to supervisor mode */
+        csrr t0, mstatus
+        
+        li t1, ~MSTATUS_MPP_MASK
+        and t0, t0, t1
+        
+        
+        /*
+         * TODO: Enable running with Supervisor User Mode
+         * access disabled.
+         */
+        li t1, MSTATUS_MPP_SUPERVISOR | MSTATUS_SUM_MASK
+        or t0, t0, t1
+        
+        csrw mstatus, t0
+        
+        li ra, PA2KA(BOOT_OFFSET)
+        csrw mepc, ra
+        
+        mret
 FUNCTION_END(jump_to_kernel)
 
@@ -88 +134 @@
 SYMBOL(boot_stack)
         .space BOOT_STACK_SIZE
+
+.section .pt, "aw", @progbits
+
+.align PAGE_WIDTH
+SYMBOL(ptl_0)
+        .fill 256, 8, 0
+        /* Identity mapping for [0; 512G) */
+        .quad 0 + (PTL_DIRTY | PTL_ACCESSED | PTL_EXECUTABLE | PTL_WRITABLE | PTL_READABLE | PTL_VALID)
+        .fill 255, 8, 0