add new dfboot loader - a complete revison of romboot code.
[openwrt/svn-archive/archive.git] / target / linux / at91-2.6 / image / dfboot / src / asm_mci_isr.S
1 #include <AT91RM9200_inc.h>
2
3 #define ARM_MODE_USER 0x10
4 #define ARM_MODE_FIQ 0x11
5 #define ARM_MODE_IRQ 0x12
6 #define ARM_MODE_SVC 0x13
7 #define ARM_MODE_ABORT 0x17
8 #define ARM_MODE_UNDEF 0x1B
9 #define ARM_MODE_SYS 0x1F
10
11 #define I_BIT 0x80
12 #define F_BIT 0x40
13 #define T_BIT 0x20
14
15
16 /* -----------------------------------------------------------------------------
17 AT91F_ASM_MCI_Handler
18 ---------------------
19 Handler called by the AIC
20
21 Save context
22 Call C handler
23 Restore context
24 ----------------------------------------------------------------------------- */
25
26 .global AT91F_ASM_MCI_Handler
27
28 AT91F_ASM_MCI_Handler:
29 /* Adjust and save LR_irq in IRQ stack */
30 sub r14, r14, #4
31 stmfd sp!, {r14}
32
33 /* Write in the IVR to support Protect Mode
34 No effect in Normal Mode
35 De-assert the NIRQ and clear the source in Protect Mode */
36 ldr r14, =AT91C_BASE_AIC
37 str r14, [r14, #AIC_IVR]
38
39 /* Save SPSR and r0 in IRQ stack */
40 mrs r14, SPSR
41 stmfd sp!, {r0, r14}
42
43 /* Enable Interrupt and Switch in SYS Mode */
44 mrs r0, CPSR
45 bic r0, r0, #I_BIT
46 orr r0, r0, #ARM_MODE_SYS
47 msr CPSR_c, r0
48
49 /* Save scratch/used registers and LR in User Stack */
50 stmfd sp!, { r1-r3, r12, r14}
51
52 ldr r1, =AT91F_MCI_Handler
53 mov r14, pc
54 bx r1
55
56 /* Restore scratch/used registers and LR from User Stack */
57 ldmia sp!, { r1-r3, r12, r14}
58
59 /* Disable Interrupt and switch back in IRQ mode */
60 mrs r0, CPSR
61 bic r0, r0, #ARM_MODE_SYS
62 orr r0, r0, #I_BIT | ARM_MODE_IRQ
63 msr CPSR_c, r0
64
65 /* Mark the End of Interrupt on the AIC */
66 ldr r0, =AT91C_BASE_AIC
67 str r0, [r0, #AIC_EOICR]
68
69 /* Restore SPSR_irq and r0 from IRQ stack */
70 ldmia sp!, {r0, r14}
71 msr SPSR_cxsf, r14
72
73 /* Restore adjusted LR_irq from IRQ stack directly in the PC */
74 ldmia sp!, {pc}^
75