diff options
Diffstat (limited to 'c/src/lib/libbsp/mips/jmr3904/start/start.S')
| -rw-r--r-- | c/src/lib/libbsp/mips/jmr3904/start/start.S | 131 |
1 files changed, 48 insertions, 83 deletions
diff --git a/c/src/lib/libbsp/mips/jmr3904/start/start.S b/c/src/lib/libbsp/mips/jmr3904/start/start.S index c484b7b0bd..525232e2c8 100644 --- a/c/src/lib/libbsp/mips/jmr3904/start/start.S +++ b/c/src/lib/libbsp/mips/jmr3904/start/start.S @@ -17,22 +17,14 @@ * they apply. */ +#include <asm.h> +#include "regs.S" + #ifdef __mips16 /* This file contains 32 bit assembly code. */ .set nomips16 #endif -#include <asm.h> -#include "regs.S" - -/* - * Set up some room for a stack. We just grab a chunk of memory. - */ -#define STACK_SIZE 0x4000 -#define GLOBAL_SIZE 0x2000 - -#define STARTUP_STACK_SIZE 0x0100 - /* This is for referencing addresses that are not in the .sdata or .sbss section under embedded-pic, or before we've set up gp. */ #ifdef __mips_embedded_pic @@ -45,10 +37,6 @@ # define LA(t,x) la t,x #endif /* __mips_embedded_pic */ - .comm __memsize, 12 - .comm __lstack, STARTUP_STACK_SIZE - .comm __stackbase,4 - .text .align 2 @@ -62,6 +50,38 @@ .ent _start _start: .set noreorder + # Get the address of start into $5 in a position independent fashion. + # This lets us know whether we have been relocated or not. + + $LF1 = . + 8 + bal $LF1 + nop +_branch: + move $5, $31 # $5 == where are we + li $6, 0x8800000c # $6 == where we want to be + #la $6,_branch + beq $5, $6, _start_in_ram + nop + # relocate the code from EEPROM to RAM + la $7, _edata +relocate: + lw $8, ($5) # $8 = *EEPROM + addu $5, $5, 4 # EEPROM++ + sw $8, ($6) # *RAM = $8 + addu $6, $6, 4 # RAM++ + bne $6, $7, relocate # copied all the way to edata? + nop + la $6, _start_in_ram + jr $6 + nop + .end _start + + + .globl _start_in_ram + .ent _start_in_ram +_start_in_ram: + nop + #ifdef __mips_embedded_pic PICBASE = .+8 bal PICBASE @@ -111,9 +131,6 @@ _start: * zero out the bss section. */ .globl __memsize - .globl get_mem_info .text - .globl __stack - .globl __global .globl zerobss .ent zerobss zerobss: @@ -124,22 +141,7 @@ zerobss: bltu v0,v1,3b addiu v0,v0,4 # executed in delay slot - la t0, __lstack # make a small stack so we - addiu sp, t0, STARTUP_STACK_SIZE # can run some C code - la a0, __memsize # get the usable memory size - jal get_mem_info - nop - - /* setup the stack pointer */ - LA (t0, __stack) # is __stack set ? - bne t0,zero,4f - nop - - /* NOTE: a0[0] contains the amount of memory available, and - not the last memory address. */ - lw t0,0(a0) # last address of memory available - la t1,K0BASE # cached kernel memory - addu t0,t0,t1 # get the end of memory address + la t0, _stack_init # initialize stack so we /* We must subtract 24 bytes for the 3 8 byte arguments to main, in case main wants to write them back to the stack. The caller is supposed to allocate stack space for parameters in registers in @@ -149,73 +151,36 @@ zerobss: Some ports need a larger alignment for the stack, so we subtract 32, which satisifes the stack for the arguments and keeps the stack pointer better aligned. */ - subu t0,t0,32 # and generate a starting stack-pointer -4: + subu t0,t0,32 move sp,t0 # set stack pointer - sw sp,__stackbase # keep this for future ref .end zerobss -/* - * initialize target specific stuff. Only execute these - * functions it they exist. - */ -#if 0 - .globl hardware_init_hook .text - .globl software_init_hook .text - .globl __do_global_dtors .text - .globl atexit .text -#endif .globl exit .text .globl init .ent init init: -#if 0 - LA (t9, hardware_init_hook) # init the hardware if needed - beq t9,zero,6f - nop - jal t9 - nop -6: - LA (t9, software_init_hook) # init the hardware if needed - beq t9,zero,7f - nop - jal t9 - nop -7: - LA (a0, __do_global_dtors) - jal atexit - nop -#endif - -#ifdef GCRT0 - .globl _ftext - .globl _extext - LA (a0, _ftext) - LA (a1, _etext) - jal monstartup - nop -#endif move a0,zero # set argc to 0 jal boot_card # call the program start function nop # fall through to the "exit" routine - jal exit # call libc exit to run the G++ + jal _sys_exit # call libc exit to run the G++ # destructors move a0,v0 # pass through the exit code .end init /* - * Exit from the application. Normally we cause a user trap - * to return to the ROM monitor for another run. NOTE: This is - * the only other routine we provide in the crt0.o object, since - * it may be tied to the "_start" routine. It also allows - * executables that contain a complete world to be linked with - * just the crt0.o object. + * _sys_exit -- Exit from the application. Normally we cause a user trap + * to return to the ROM monitor for another run. NOTE: This is + * the only other routine we provide in the crt0.o object, since + * it may be tied to the "_start" routine. It also allows + * executables that contain a complete world to be linked with + * just the crt0.o object. */ - -FRAME(_sys_exit,sp,0,ra) + .globl _sys_exit + .ent _sys_exit +_sys_exit: 7: #ifdef GCRT0 jal _mcleanup @@ -226,6 +191,6 @@ FRAME(_sys_exit,sp,0,ra) nop b 7b # but loop back just in-case nop -ENDFRAME(_sys_exit) + .end _sys_exit /* EOF crt0.S */ |