diff options
Diffstat (limited to 'libgloss/mt/crt0-64-001.S')
| -rw-r--r-- | libgloss/mt/crt0-64-001.S | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/libgloss/mt/crt0-64-001.S b/libgloss/mt/crt0-64-001.S new file mode 100644 index 000000000..b78e7808e --- /dev/null +++ b/libgloss/mt/crt0-64-001.S @@ -0,0 +1,144 @@ +; crt0_2.s - Startup code for the mrisc1. This code initializes the C +; run-time model. +; +; 12Nov01 (DJK) - The return code from main was not being passed to exit(). +; Now it is passed as a parameter in R1. +; +; 10Sep01 (DJK) - The function exit() does not return. However, in the +; the case of device error (if the halt bit does not +; function properly, for instance), then a catch loop +; has been added. +; +; +; Copyright 2001, 2002, 2003, 2004 Morpho Technologies, Inc. +; + + ; Create a label for the start of the eh_frame section. + .section .eh_frame +__eh_frame_begin: + + .equ HALT_REG, 0x300 + .section .text + .global _start +_start: + ;; Initialize the stack pointer + ldui sp, #%hi16(__stack) + addui sp, sp, #%lo16(__stack) + or fp, sp, sp + + ;; Copy data from ROM to Frame Buffer (on-chip memory) + ldui r9, #%hi16(_fbdata_start) + ori r9, r9, #%lo16(_fbdata_start) + ldui r10, #%hi16(_fbdata_end) + ori r10, r10, #%lo16(_fbdata_end) + ldui r11, #%hi16(__FRAME_BUFFER_START) + brle r10, r9, .Lnext1 + ori r11, r11, #%lo16(__FRAME_BUFFER_START) +.Lcpy0: + ldw r5, r9, #$0 + addi r9, r9, #$4 + stw r5, r11, #$0 + brlt r9, r10, .Lcpy0 + addi r11, r11, #$4 + +.Lnext1: + ;; Copy data from ROM to External Memory (off-chip memory) + ldui r9, #%hi16(_extdata_start) + ori r9, r9, #%lo16(_extdata_start) + ldui r10, #%hi16(_extdata_end) + ori r10, r10, #%lo16(_extdata_end) + ldui r11, #%hi16(__EXTERNAL_MEMORY_START) + brle r10, r9, .Lnext2 + ori r11, r11, #%lo16(__EXTERNAL_MEMORY_START) +.Lcpy1: + ldw r5, r9, #$0 + addi r9, r9, #$4 + stw r5, r11, #$0 + brlt r9, r10, .Lcpy1 + addi r11, r11, #$4 + + +.Lnext2: + ;; Zero the bss space + ldui r9, #%hi16(__bss_start) + addui r9, r9, #%lo16(__bss_start) + ldui r10, #%hi16(__bss_end) + addui r10, r10, #%lo16(__bss_end) + or r0, r0, r0 + brle r10, r9, .Lnext3 + or r0, r0, r0 +.Lcpy2: + stw r0, r9, #0 + addi r9, r9, #4 + or r0, r0, r0 ; nop + brle r9, r10, .Lcpy2 + or r0, r0, r0 ; nop + +.Lnext3: + ;; Zero the external memory bss section + ldui r9, #%hi16(_extbss_start) + ori r9, r9, #%lo16(_extbss_start) + ldui r10, #%hi16(_extbss_end) + ori r10, r10, #%lo16(_extbss_end) + or r0, r0, r0 + brle r10, r9, .Lnext4 + or r0, r0, r0 +.Lcpy3: + stw r0, r9, #$0 + addi r9, r9, #$4 + or r0, r0, r0 + brle r9, r10, .Lcpy3 + or r0, r0, r0 + +.Lnext4: + ;; Call global and static constructors + ldui r10, #%hi16(_init) + ori r10, r10, #%lo16(_init) + or r0, r0, r0 ; nop + jal r14, r10 + or r0, r0, r0 ; nop + + ;; Setup destructors to be called from exit. + ;; (Just in case main never returns....) + ldui r10, #%hi16(atexit) + ori r10, r10, #%lo16(atexit) + ldui r1, #%hi16(_fini) + ori r1, r1, #%lo16(_fini) + or r0, r0, r0 ; nop + jal r14, r10 + or r0, r0, r0 ; nop + + ;; Initialise argc, argv and envp to empty + addi r1, r0, #0 + addi r2, r0, #0 + addi r3, r0, #0 + + ;; Call main + ldui r10, #%hi16(main) + ori r10, r10, #%lo16(main) + or r0, r0, r0 ; nop + jal r14, r10 + or r0, r0, r0 ; nop + + ;; DJK - Added 12Nov01. Pass main's return value to exit. + or r1, r11, r0 + + ;; Jump to exit + ldui r10, #%hi16(exit) + ori r10, r10, #%lo16(exit) + or r0, r0, r0 ; nop + jal r14, r10 + or r0, r0, r0 ; nop + + ;; Exit does not return, however, this code is to catch an + ;; error if it does. Set the processor into sleep mode. + ori r1, r0, #$1 + stw r1, r0, #HALT_REG + or r0, r0, r0 + or r0, r0, r0 + or r0, r0, r0 + or r0, r0, r0 + or r0, r0, r0 +.Lend: + jmp .Lend + or r0, r0, r0 |