From a1f49718aee378fa075303c86106309091d56b80 Mon Sep 17 00:00:00 2001
From: Christian Cunningham <cc@localhost>
Date: Mon, 31 Jan 2022 19:05:50 -0700
Subject: Break exceptions off to own files
---
linker.ld | 1 +
src/boot.S | 139 +--------------------------------------------
src/cpu/irq.c | 29 +---------
src/exceptions/data.S | 29 ++++++++++
src/exceptions/fiq.S | 26 +++++++++
src/exceptions/irq.S | 8 +++
src/exceptions/prefetch.S | 20 +++++++
src/exceptions/svc.S | 45 +++++++++++++++
src/exceptions/undefined.S | 34 +++++++++++
src/lib/mem.c | 8 +--
src/sys/core.c | 6 +-
src/sys/kernel.S | 2 +-
12 files changed, 176 insertions(+), 171 deletions(-)
create mode 100644 src/exceptions/data.S
create mode 100644 src/exceptions/fiq.S
create mode 100644 src/exceptions/irq.S
create mode 100644 src/exceptions/prefetch.S
create mode 100644 src/exceptions/svc.S
create mode 100644 src/exceptions/undefined.S
diff --git a/linker.ld b/linker.ld
index 17c951a..474bdeb 100644
--- a/linker.ld
+++ b/linker.ld
@@ -9,6 +9,7 @@ SECTIONS
.text :
{
KEEP(*(.text.boot))
+ KEEP(*(.text.exceptions))
KEEP(*(.text.kernel))
*(.text*)
}
diff --git a/src/boot.S b/src/boot.S
index 0cbd8e3..8c9becf 100644
--- a/src/boot.S
+++ b/src/boot.S
@@ -6,7 +6,7 @@
_start:
reset:
- cpsid if
+ cpsid aif
// disable core0,1,2.
mrc p15, #0, r1, c0, c0, #5
and r1, r1, #3
@@ -50,12 +50,10 @@ reset:
mov r8, #0
b 2f
-1:
- // store multiple at r4.
+1: // store multiple at r4.
stmia r4!, {r5-r8}
- // If we are still below bss_end, loop.
-2:
+2: // If we are still below bss_end, loop.
cmp r4, r9
blo 1b
@@ -63,12 +61,6 @@ reset:
ldr r3, =kernel_main
blx r3
-irq:
- push {r0,r1,r2,r3,r4,r5,r6,r7,r8,r9,r10,r11,r12,lr}
- bl c_irq_handler
- pop {r0,r1,r2,r3,r4,r5,r6,r7,r8,r9,r10,r11,r12,lr}
- subs pc, lr, #4
-
// TODO: Each core needs to set up their stacks
core1run:
core2run:
@@ -78,123 +70,6 @@ io_halt:
wfi
b io_halt
-undefined:
- stmfd sp!, {r0-r12,lr}
- ldr r4, [lr, #-4]
- mov r0, #0
- mov r1, #17
- ldr r2, =undefined_msg
- bl draw_string
- mov r0, #18
- mov r1, #17
- mov r2, r4
- bl draw_hex32
- mov r0, #27
- mov r1, #17
- ldr r2, =undefined_at
- bl draw_string
- // Output lr
- mov r1, #0x1000
- ldr r0, [r1, #-4]
- sub r2, r0, #4
- mov r0, #31
- mov r1, #17
- bl draw_hex32
- // Skip instruction for now
- // In future,
- // ldmfd sp!, {r0-r12,lr} // Note the lack of ^ since subs will handle it
- // subs pc, lr, #4
- ldmfd sp!, {r0-r12,pc}^
-svc:
- cpsid f
- stmfd sp!, {r0-r12,lr}
- ldr r0, [lr, #-4]
- bic r0, #0xFF000000
- // SVC #0 returns to supervisor mode
- // TODO: Make supervisor mode return to a specific location
- // (rather than to a user location) such as the kernel loop
- cmp r0, #3
- bgt svc_exit
- beq svc_000003
- cmp r0, #2
- beq svc_000002
- cmp r0, #1
- beq svc_000001
- cmp r0, #1
- beq svc_000000
-svc_000000:
- cps #0x13
- b svc_exit
-svc_000001:
- b svc_exit
-svc_000002:
- ldmfd sp!, {r0-r12,lr}
- b schedule
-svc_000003:
- ldr r3, =scheduler
- ldr r2, [r3, #0]
- ldr r1, [r2, #8] // sp_base
- cmp r1, #-1
- beq svc_exit
- ldr r3, =stacks_table
- mov r0, #0
- strb r0, [r3, r1]
- // Free the thread after freeing the stack
- mov r0, r2
- bl free
- b svc_exit
-svc_exit:
- ldmfd sp!, {r0-r12,pc}^
-prefetch:
- stmfd sp!, {r0-r12,lr}
- mov r4, lr
- mov r0, #0
- mov r1, #16
- ldr r2, =prefetch_msg
- bl draw_string
- // Output return address
- mov r0, #17
- mov r1, #16
- mov r2, r4
- bl draw_hex32
- ldmfd sp!, {r0-r12,lr}
- subs pc, lr, #4
-data:
- stmfd sp!, {r0-r12,lr}
- mov r4, lr
- mov r0, #0
- mov r1, #15
- ldr r2, =data_msg
- bl draw_string
- // Output return address
- mov r0, #13
- mov r1, #15
- mov r2, r4
- sub r2, #8
- bl draw_hex32
- mov r0, #22
- mov r1, #15
- ldr r2, [r4, #-8]
- bl draw_hex32
- ldmfd sp!, {r0-r12,lr}
- subs pc, lr, #4 // Should be 8 once I can actually handle the abort
-fiq:
- stmfd sp!, {r0-r12,lr}
- bl c_fiq_handler
- cmp r0, #1
- bne 1f
- ldmfd sp!, {r0-r12,lr}
- sub lr, #4
- push {r3}
- ldr r3, =irqlr
- str lr, [r3, #0]
- pop {r3}
- cps #0x13
- b schedule
-1:
- ldmfd sp!, {r0-r12,lr}
- subs pc, lr, #4
-
.align 5
vector:
ldr pc, reset_handler
@@ -214,11 +89,3 @@ data_handler: .word data
unused_handler: .word io_halt
irq_handler: .word irq
fiq_handler: .word fiq
-
-.section .data
-undefined_msg: .asciz "Undefined Handler"
-undefined_at: .asciz "@ 0x"
-svc_msg: .asciz "SVC Handler #"
-prefetch_msg: .asciz "Prefetch Handler"
-data_msg: .asciz "Data Handler"
-fiq_msg: .asciz "FIQ\n"
diff --git a/src/cpu/irq.c b/src/cpu/irq.c
index e6c6a80..7f2a89e 100644
--- a/src/cpu/irq.c
+++ b/src/cpu/irq.c
@@ -97,49 +97,24 @@ void handle_data(unsigned char data)
if (off < 2048) {
// Newline Case
if (data == 0x0D) {
- for(int i = off; i>=0;i--)
- cmd[i] = 0x0;
- off = 0;
// Backspace Case
} else if (data == 0x08 || data == 0x7F) {
- if (off > 0) {
- off -= 1;
- }
- cmd[off] = 0x0;
// Lock Case
} else if (data == 0x6C) {
- cmd[off] = (char) data;
- off += 1;
lock_mutex(&exe_cnt_m, SYS_PID);
// Release Case
} else if (data == 0x72) {
- cmd[off] = (char) data;
- off += 1;
release_mutex(&exe_cnt_m, SYS_PID);
} else if (data == 0x61) {
- cmd[off] = (char) data;
- off += 1;
add_thread(testfxn, 0, 3);
} else if (data == 0x62) {
- cmd[off] = (char) data;
- off += 1;
add_thread(uart_scheduler, 0, 2);
+ } else if (data == 0x63) {
+ add_thread(heap_info, 0, 2);
// Else output
} else {
- cmd[off] = (char) data;
- off += 1;
}
} else if (off == 2048) {
- if (data == 0x0D) {
- for(int i = off; i>=0;i--)
- cmd[i] = 0x0;
- off = 0;
- } else if (data == 0x08 || data == 0x7F) {
- if (off > 0) {
- off -= 1;
- }
- cmd[off] = 0x0;
- }
}
cmdidx = off;
g_Drawer.x = 0;
diff --git a/src/exceptions/data.S b/src/exceptions/data.S
new file mode 100644
index 0000000..2268de5
--- /dev/null
+++ b/src/exceptions/data.S
@@ -0,0 +1,29 @@
+.section ".text.exceptions"
+.globl data
+data:
+ cpsid aif
+ stmfd sp!, {r0-r12,lr}
+ mov r4, lr
+ mov r0, #0
+ mov r1, #15
+ ldr r2, =data_msg
+ bl draw_string
+ // Output return address
+ mov r0, #13
+ mov r1, #15
+ mov r2, r4
+ sub r2, #8
+ bl draw_hex32
+ mov r0, #22
+ mov r1, #15
+ ldr r2, [r4, #-8]
+ bl draw_hex32
+ mov r0, #32
+ mov r1, #15
+ mrs r2, spsr
+ bl draw_hex32
+ ldmfd sp!, {r0-r12,lr}
+ subs pc, lr, #4 // Should be 8 once I can actually handle the abort
+
+.section .data
+data_msg: .asciz "Data Handler"
diff --git a/src/exceptions/fiq.S b/src/exceptions/fiq.S
new file mode 100644
index 0000000..f323a02
--- /dev/null
+++ b/src/exceptions/fiq.S
@@ -0,0 +1,26 @@
+.section ".text.exceptions"
+.globl fiq
+fiq:
+ cpsid aif
+ stmfd sp!, {r0-r12,lr}
+ bl c_fiq_handler
+ cmp r0, #1
+ bne 1f
+ mrs r1, spsr
+ and r1, r1, #0x1f
+ cmp r1, #0x10
+ bne 1f
+ ldmfd sp!, {r0-r12,lr}
+ sub lr, #4
+ push {r3}
+ ldr r3, =irqlr
+ str lr, [r3, #0]
+ pop {r3}
+ cps #0x13
+ b schedule
+1:
+ ldmfd sp!, {r0-r12,lr}
+ subs pc, lr, #4
+
+.section .data
+fiq_msg: .asciz "FIQ\n"
diff --git a/src/exceptions/irq.S b/src/exceptions/irq.S
new file mode 100644
index 0000000..025fc41
--- /dev/null
+++ b/src/exceptions/irq.S
@@ -0,0 +1,8 @@
+.section ".text.exceptions"
+.globl irq
+irq:
+ cpsid aif
+ push {r0,r1,r2,r3,r4,r5,r6,r7,r8,r9,r10,r11,r12,lr}
+ bl c_irq_handler
+ pop {r0,r1,r2,r3,r4,r5,r6,r7,r8,r9,r10,r11,r12,lr}
+ subs pc, lr, #4
diff --git a/src/exceptions/prefetch.S b/src/exceptions/prefetch.S
new file mode 100644
index 0000000..1aeba10
--- /dev/null
+++ b/src/exceptions/prefetch.S
@@ -0,0 +1,20 @@
+.section ".text.exceptions"
+.globl prefetch
+prefetch:
+ cpsid aif
+ stmfd sp!, {r0-r12,lr}
+ mov r4, lr
+ mov r0, #0
+ mov r1, #16
+ ldr r2, =prefetch_msg
+ bl draw_string
+ // Output return address
+ mov r0, #17
+ mov r1, #16
+ mov r2, r4
+ bl draw_hex32
+ ldmfd sp!, {r0-r12,lr}
+ subs pc, lr, #4
+
+.section .data
+prefetch_msg: .asciz "Prefetch Handler"
diff --git a/src/exceptions/svc.S b/src/exceptions/svc.S
new file mode 100644
index 0000000..a5e9982
--- /dev/null
+++ b/src/exceptions/svc.S
@@ -0,0 +1,45 @@
+.section ".text.exceptions"
+.globl svc
+svc:
+ cpsid aif
+ stmfd sp!, {r0-r12,lr}
+ ldr r0, [lr, #-4]
+ bic r0, #0xFF000000
+ // SVC #0 returns to supervisor mode
+ // TODO: Make supervisor mode return to a specific location
+ // (rather than to a user location) such as the kernel loop
+ cmp r0, #3
+ bgt svc_exit
+ beq svc_000003
+ cmp r0, #2
+ beq svc_000002
+ cmp r0, #1
+ beq svc_000001
+ cmp r0, #1
+ beq svc_000000
+svc_000000:
+ cps #0x13
+ b svc_exit
+svc_000001:
+ b svc_exit
+svc_000002:
+ ldmfd sp!, {r0-r12,lr}
+ b schedule
+svc_000003:
+ ldr r3, =scheduler
+ ldr r2, [r3, #0]
+ ldr r1, [r2, #8] // sp_base
+ cmp r1, #-1
+ beq svc_exit
+ ldr r3, =stacks_table
+ mov r0, #0
+ strb r0, [r3, r1]
+ // Free the thread after freeing the stack
+ mov r0, r2
+ bl free
+ b svc_exit
+svc_exit:
+ ldmfd sp!, {r0-r12,pc}^
+
+.section .data
+svc_msg: .asciz "SVC Handler #"
diff --git a/src/exceptions/undefined.S b/src/exceptions/undefined.S
new file mode 100644
index 0000000..b8eab29
--- /dev/null
+++ b/src/exceptions/undefined.S
@@ -0,0 +1,34 @@
+.section ".text.exceptions"
+.globl undefined
+undefined:
+ cpsid aif
+ stmfd sp!, {r0-r12,lr}
+ ldr r4, [lr, #-4]
+ mov r0, #0
+ mov r1, #17
+ ldr r2, =undefined_msg
+ bl draw_string
+ mov r0, #18
+ mov r1, #17
+ mov r2, r4
+ bl draw_hex32
+ mov r0, #27
+ mov r1, #17
+ ldr r2, =undefined_at
+ bl draw_string
+ // Output lr
+ mov r1, #0x1000
+ ldr r0, [r1, #-4]
+ sub r2, r0, #4
+ mov r0, #31
+ mov r1, #17
+ bl draw_hex32
+ // Skip instruction for now
+ // In future,
+ // ldmfd sp!, {r0-r12,lr} // Note the lack of ^ since subs will handle it
+ // subs pc, lr, #4
+ ldmfd sp!, {r0-r12,pc}^
+
+.section .data
+undefined_msg: .asciz "Undefined Handler"
+undefined_at: .asciz "@ 0x"
diff --git a/src/lib/mem.c b/src/lib/mem.c
index 73c6a48..2f50d3d 100644
--- a/src/lib/mem.c
+++ b/src/lib/mem.c
@@ -222,10 +222,10 @@ void free(void* memloc)
unsigned char size = base[MEM_SIZE_OFFSET];
// TODO: Use Null PID
base[MEM_USE_OFFSET] = 0;
- // // Clear out old memory
- // for(unsigned int i = 0; i < size; i++) {
- // base[i + MEM_BASE_SIZE] = 0;
- // }
+ // Clear out old memory
+ for(unsigned int i = 0; i < size; i++) {
+ base[i + MEM_BASE_SIZE] = 0;
+ }
// If it is the last entry, clear it and move the heap top down
if (base + size + MEM_META_SIZE == rpi_heap_top) {
while(base[MEM_USE_OFFSET] == 0 && base >= rpi_heap) {
diff --git a/src/sys/core.c b/src/sys/core.c
index d84770d..39eaffd 100644
--- a/src/sys/core.c
+++ b/src/sys/core.c
@@ -61,9 +61,9 @@ void sysinit(void)
// Start Scheduler
init_scheduler();
- // Enable IRQ & FIQ
- enableirq();
- enablefiq();
+ //// // Enable IRQ & FIQ
+ //// enableirq();
+ //// enablefiq();
add_thread(testlocal, 0, 0);
add_thread(testlocal, 0, 1);
diff --git a/src/sys/kernel.S b/src/sys/kernel.S
index b76df62..93074b6 100644
--- a/src/sys/kernel.S
+++ b/src/sys/kernel.S
@@ -17,7 +17,7 @@ kernel_main:
// svc #1
// mrs r0, cpsr
// bl uart_hexn
- cps #0x10
+ cpsie aif, #0x10
svc #2 // Start scheduling!
1:
wfe
--
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