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-rw-r--r--src/exceptions/svc.S56
1 files changed, 43 insertions, 13 deletions
diff --git a/src/exceptions/svc.S b/src/exceptions/svc.S
index 88716db..a95c7a6 100644
--- a/src/exceptions/svc.S
+++ b/src/exceptions/svc.S
@@ -6,20 +6,12 @@ svc:
// Get the SVC Exception #
ldr r0, [lr, #-4]
bic r0, #0xFF000000
- // Jump to the appropriate Call
- cmp r0, #5
+ cmp r0, #7
+ // Check it is within our defined SVC
bgt svc_exit
- beq svc_000005
- cmp r0, #4
- beq svc_000004
- cmp r0, #3
- beq svc_000003
- cmp r0, #2
- beq svc_000002
- cmp r0, #1
- beq svc_000001
- cmp r0, #0
- beq svc_000000
+ //// Jump to the appropriate Call
+ adr r3, svc_table
+ ldr pc, [r3, r0, LSL #2]
svc_000000: // SYS_YIELD
bl yield
ldmfd sp!, {r0-r12,lr}
@@ -79,5 +71,43 @@ svc_000005: // Release Lock
ldmfd sp!, {r0-r12,lr}
b schedule
b svc_exit
+svc_000006: // Semaphore decrease
+ ldr r0, [sp, #0] // struct Semaphore* s
+1: clrex
+ ldrex r2, [r0, #0]
+ cmp r2, #0
+ beq svc_000006_delay_semaphore
+ sub r1, r2, #1
+ strexeq r2, r1, [r0, #0]
+ teq r2, #0
+ bne 1b
+ dmb
+ b svc_exit
+svc_000006_delay_semaphore:
+ bl sched_semaphore_yield
+ ldmfd sp!, {r0-r12,lr}
+ sub lr, #4
+ b schedule
+svc_000007: // Semaphore increase
+ ldr r0, [sp, #0] // struct Semaphore* s
+1: clrex
+ ldrex r2, [r0, #0]
+ add r1, r2, #1
+ strexeq r2, r1, [r0, #0]
+ teq r2, #0
+ bne 1b
+ dmb
+ bl sched_semaphore_resurrect
+ b svc_exit
svc_exit:
ldmfd sp!, {r0-r12,pc}^
+
+svc_table:
+ .word svc_000000
+ .word svc_000001
+ .word svc_000002
+ .word svc_000003
+ .word svc_000004
+ .word svc_000005
+ .word svc_000006
+ .word svc_000007