[58127230] | 1 | /* A fake 'bios' which does nothing but move a kernel image |
---|
| 2 | * to RAM address zero and then starts that... |
---|
| 3 | */ |
---|
[f33e6c0] | 4 | |
---|
| 5 | #include <bsp/residual.h> |
---|
| 6 | |
---|
[58127230] | 7 | #define LD_CACHE_LINE_SIZE 5 |
---|
| 8 | #define INIT_STACK (0x100 - 16) /* 16-byte/svr4 aligned */ |
---|
| 9 | |
---|
| 10 | /* These offsets must correspond to declaration in qemu_fakeres.c */ |
---|
| 11 | #define DAT_LEN 0 |
---|
| 12 | #define RES_OFF 4 |
---|
| 13 | #define CMD_OFF 8 |
---|
| 14 | #define CMD_LEN 12 |
---|
| 15 | #define IMG_ADR 16 |
---|
| 16 | |
---|
| 17 | /* Non-volatile registers */ |
---|
| 18 | #define OBASE 30 |
---|
| 19 | #define PCID 25 |
---|
| 20 | #define PCIA 26 |
---|
| 21 | |
---|
| 22 | #define PCI_MAX_DEV 32 |
---|
| 23 | |
---|
[6464a2b] | 24 | #define BA_OPCODE(tgt) ((18<<(31-5)) | 2 | ((tgt) & 0x03fffffc)) |
---|
| 25 | |
---|
[58127230] | 26 | .global fake_data |
---|
| 27 | .global res_set_memsz |
---|
| 28 | |
---|
| 29 | .global _start |
---|
| 30 | _start: |
---|
| 31 | lis 1, INIT_STACK@h |
---|
| 32 | ori 1,1,INIT_STACK@l |
---|
[6464a2b] | 33 | |
---|
| 34 | /* qemu 0.14.1 has the wrong exception prefix for 74xx CPUs |
---|
| 35 | * (bug 811683). Work around this by putting a stub at 0x00000X00 |
---|
| 36 | * which simply jumps to high memory. We only need the SC exception |
---|
| 37 | * for now. |
---|
| 38 | */ |
---|
| 39 | lis 3, BA_OPCODE(0xfff00000)@h |
---|
| 40 | ori 3, 3, BA_OPCODE(0xfff00000)@l |
---|
| 41 | li 4, 0x0c00 |
---|
| 42 | add 3, 3, 4 |
---|
| 43 | stw 3, 0(4) |
---|
| 44 | dcbf 0, 4 |
---|
| 45 | icbi 0, 4 |
---|
| 46 | |
---|
[58127230] | 47 | bl pci_irq_set |
---|
| 48 | /* copy residual to RAM and fix up; |
---|
| 49 | * this routine returns a pointer to |
---|
| 50 | * a 'fake_data' struct. If reading |
---|
| 51 | * NVRAM failed then the return value |
---|
| 52 | * points to a fall-back version in |
---|
| 53 | * ROM... |
---|
| 54 | */ |
---|
| 55 | bl res_copy |
---|
| 56 | /* fake_data pointer to R29 */ |
---|
| 57 | mr 29, 3 |
---|
| 58 | |
---|
| 59 | /* Load up R3..R5 with PreP mandated |
---|
| 60 | * values (R3: residual, R4: kernel image, |
---|
| 61 | * R5: OpenFirmware PTR (or NULL). |
---|
| 62 | */ |
---|
| 63 | |
---|
| 64 | /* load R3 with residual pointer */ |
---|
| 65 | lwz 3, RES_OFF(29) |
---|
| 66 | add 3, 3, 29 |
---|
| 67 | |
---|
| 68 | /* load R4 with image address */ |
---|
| 69 | lwz 4, IMG_ADR(29) |
---|
| 70 | |
---|
| 71 | /* load R5 with zero (OFW = NULL) */ |
---|
| 72 | li 5, 0 |
---|
| 73 | /* EXTENSION: R6 = cmdline start */ |
---|
| 74 | lwz 6, CMD_OFF(29) |
---|
| 75 | add 6, 6, 29 |
---|
| 76 | /* EXTENSION: R7 = cmdline end */ |
---|
| 77 | lwz 7, CMD_LEN(29) |
---|
| 78 | add 7, 7, 6 |
---|
| 79 | |
---|
| 80 | /* jump to image address */ |
---|
| 81 | mtctr 4 |
---|
| 82 | bctr |
---|
| 83 | |
---|
| 84 | .org 0x100 |
---|
| 85 | b _start |
---|
| 86 | |
---|
| 87 | .org 0x110 |
---|
| 88 | template: |
---|
| 89 | mfsrr0 30 |
---|
| 90 | mfsrr1 31 |
---|
| 91 | 1: b 1b |
---|
| 92 | template_end: |
---|
| 93 | |
---|
| 94 | .org 0xc00 |
---|
| 95 | b monitor |
---|
| 96 | |
---|
| 97 | |
---|
| 98 | .org 0x4000 |
---|
| 99 | codemove: /* src/dst are cache-aligned */ |
---|
| 100 | addi 5,5,(1<<LD_CACHE_LINE_SIZE)-1 |
---|
| 101 | srwi 5,5,LD_CACHE_LINE_SIZE |
---|
| 102 | addi 3,3,-4 |
---|
| 103 | addi 4,4,-4 |
---|
| 104 | 1: |
---|
| 105 | li 0, (1<<LD_CACHE_LINE_SIZE) |
---|
| 106 | mtctr 0 |
---|
| 107 | 2: |
---|
| 108 | lwzu 0, 4(3) |
---|
| 109 | stwu 0, 4(4) |
---|
| 110 | bdnz 2b |
---|
| 111 | dcbf 0,4 |
---|
| 112 | icbi 0,4 |
---|
| 113 | addic. 5,5,-1 |
---|
| 114 | bne 1b |
---|
| 115 | blr |
---|
| 116 | |
---|
| 117 | cpexc: |
---|
| 118 | lis 3,template@h |
---|
| 119 | ori 3,3,template@l |
---|
| 120 | li 5,template_end-template |
---|
| 121 | b codemove |
---|
| 122 | |
---|
| 123 | monitor: |
---|
| 124 | stwu 1,-16(1) |
---|
| 125 | stw OBASE, 8(1) |
---|
| 126 | lis OBASE, 0x80000000@h |
---|
| 127 | cmplwi 10,0x63 /* enter_monitor -> RESET */ |
---|
| 128 | bne 10f |
---|
| 129 | hwreset: |
---|
| 130 | li 3,1 |
---|
| 131 | stb 3,0x92(OBASE) |
---|
| 132 | 1: b 1b |
---|
| 133 | 10: cmplwi 10,0x1d /* .NETCTRL -> ignore */ |
---|
| 134 | bne 10f |
---|
| 135 | b ret_from_mon |
---|
| 136 | 10: b hwreset /* unknown -> RESET */ |
---|
| 137 | |
---|
| 138 | ret_from_mon: |
---|
| 139 | lwz OBASE,8(1) |
---|
| 140 | lwz 1,0(1) |
---|
| 141 | rfi |
---|
| 142 | |
---|
| 143 | rcb: |
---|
| 144 | stwbrx 3, 0, PCIA |
---|
| 145 | lbzx 3, 0, PCID |
---|
| 146 | blr |
---|
| 147 | |
---|
| 148 | wcb: |
---|
| 149 | stwbrx 3, 0, PCIA |
---|
| 150 | stbx 4, 0, PCID |
---|
| 151 | blr |
---|
| 152 | |
---|
| 153 | rcd: |
---|
| 154 | stwbrx 3, 0, PCIA |
---|
| 155 | lwbrx 3, 0, PCID |
---|
| 156 | blr |
---|
| 157 | |
---|
| 158 | /* fixup pci interrupt line register according to what |
---|
| 159 | * qemu does: line = ((pin-1) + slot_no) & 1 ? 11 : 9; |
---|
| 160 | */ |
---|
| 161 | pci_irq_set: |
---|
| 162 | /* set up stack frame */ |
---|
| 163 | stwu 1, -32(1) |
---|
| 164 | mflr 0 |
---|
| 165 | stw 0, 32+4(1) |
---|
| 166 | /* load counter with # of PCI devs */ |
---|
| 167 | li 0, PCI_MAX_DEV |
---|
| 168 | mtctr 0 |
---|
| 169 | /* save non-volatile registers we use |
---|
| 170 | * in stack frame |
---|
| 171 | */ |
---|
| 172 | stw 20, 8(1) |
---|
| 173 | stw PCIA, 12(1) |
---|
| 174 | stw PCID, 16(1) |
---|
| 175 | /* load non-volatile registers with |
---|
| 176 | * intended values. |
---|
| 177 | */ |
---|
| 178 | lis 20, 0x80000000@h /* key for slot # 0 */ |
---|
| 179 | lis PCIA, 0x80000cf8@h /* PCI config space address reg */ |
---|
| 180 | ori PCIA, PCIA, 0x80000cf8@l |
---|
| 181 | addi PCID, PCIA, 4 /* PCI config space data reg */ |
---|
| 182 | |
---|
| 183 | /* loop over all slots and fix up PCI IRQ LINE */ |
---|
| 184 | 1: |
---|
| 185 | mr 3, 20 |
---|
| 186 | bl rcd |
---|
| 187 | addi 3, 3, 1 |
---|
| 188 | cmplwi 3, 0 /* slot empty (= -1 + 1 = 0) ? */ |
---|
| 189 | beq 2f |
---|
| 190 | addi 3, 20, 0x3d |
---|
| 191 | bl rcb |
---|
| 192 | cmplwi 3, 0 |
---|
| 193 | beq 2f |
---|
| 194 | slwi 4, 3, 11 |
---|
| 195 | addi 3, 20, 0x3c |
---|
| 196 | xor 4, 4, 3 /* bit 11 = slot # + irq_num [zero-based] + 1 */ |
---|
| 197 | andi. 4, 4, 0x0800 |
---|
| 198 | li 4, 11 |
---|
| 199 | beq 3f |
---|
| 200 | li 4, 9 |
---|
| 201 | 3: |
---|
| 202 | bl wcb |
---|
| 203 | 2: |
---|
| 204 | addi 20, 20, 0x0800 /* next slot */ |
---|
| 205 | bdnz 1b |
---|
| 206 | |
---|
| 207 | /* restore and return */ |
---|
| 208 | lwz 20, 32+4(1) |
---|
| 209 | mtlr 20 |
---|
| 210 | lwz PCID, 16(1) |
---|
| 211 | lwz PCIA, 12(1) |
---|
| 212 | lwz 20, 8(1) |
---|
| 213 | lwz 1, 0(1) |
---|
| 214 | blr |
---|
| 215 | |
---|
| 216 | .section .romentry, "ax" |
---|
| 217 | b _start |
---|