On Mon, 2020-09-07 at 22:24 +0300, Yusuf Altıparmak wrote: > CAUTION: This email originated from outside of the organization. Do not click > links or open attachments unless you recognize the sender and know the > content is safe. > > > Hello, > > I want to modify U-boot to relocate itself to on-board SRAM of chip (T1042 > demo board) instead of DRAM. > > At first, there is call list in u-boot/common/board_f.c and it has a line > to call dram_init. I will change this line with my custom sram_init > function. > > [image: Capture.PNG] > > The function board_f() is being called in start.S which is located at > u-boot/arch/powerpc/cpu/mpc85xx/ > > start.S file also includes a region to relocate itself by changing Link > Register. Code region is: > > */** > ** void relocate_code(addr_sp, gd, addr_moni)* > *** > ** This "function" does not return, instead it continues in RAM* > ** after relocating the monitor code.* > *** > ** r3 = dest* > ** r4 = src* > ** r5 = length in bytes* > ** r6 = cachelinesize* > **/* > *.globl relocate_code* > *relocate_code:* > *mr r1,r3 /* Set new stack pointer */* > *mr r9,r4 /* Save copy of Init Data pointer */* > *mr r10,r5 /* Save copy of Destination Address */* > > *GET_GOT* > *#ifndef CONFIG_SPL_SKIP_RELOCATE* > *mr r3,r5 /* Destination Address */* > *lis r4,CONFIG_SYS_MONITOR_BASE@h /* Source Address */* > *ori r4,r4,CONFIG_SYS_MONITOR_BASE@l* > *lwz r5,GOT(__init_end)* > *sub r5,r5,r4* > *li r6,CONFIG_SYS_CACHELINE_SIZE /* Cache Line Size */* > > > My question is, in above code, how relocate_code() function is calculating > the jump address of Link Register (CONFIG_SYS_MONITOR_BASE@h). > > What should be done to change it to point SRAM of t1042 after we initialize > it in board_init_f() function. ?
I don't think you should change anything here. Just make gd->relocaddr point to somewhere in SRAM Jocke
